blower fan

[killerazonic]

So i have a problem, the blower fan will only blow air on 1,2,3. As soon as you put it on "4" it shuts off. My local GM dealer told me it was a relay, but they are kinda stupid, so im not sure if i believe them. And they wanted an a#$ load to fix it. And the guys at napa cant find any relay for it, they thought it may be a resistor, but dont know.

So my question is, what would make just one of the fan speeds stop working?

'99 s10 4x4 w/ AC

[Hammer Head]

Could be the blower motor itself, fan switch (potentiometer), or I have heard of some guy having a wiring issue cause this.

[Sparky2263]

The high blower relay is most likely bad. Orange wire at the relay is energized when selecting high. A test lamp will reveal if it's got power. Or just turn the blower to high and whack the relay with a small hammer. It'll probably start working.

Oh yeah, that's a good indication the relay is bad........

Tried to upload a pic of the relay. No go. It's on the housing to the left (drivers) of the blower motor.

I'll try the pic again later.

[killerazonic]

ok so i found the relay

the number on the top is 12193611

im not sure if thats of any relevance

but im going to look on the internet for something then go to NAPA tomorrow

[Sparky2263]

Did you smack it around to see if it would start working? Check it with a test light?

[killerazonic]

i went and got a different relay and that didn't work. The guys at NAPA think that it may be the switch, they told me to take it apart and test the wiring. Or they think that it may be the resistor, tho i don't know why. so now i have to pull apart part of my dash again (F$)$**&% im so tired of doing that) and pull the switch.

thanks sparky

[tmoney0501]

i have this same exact problem. when i put my A/C on high (4) it just doesnt blow anythign at all. i have no clue what the problem could be, but if you find out, pleeeeeease let me know.

[87wildside]

I had this problem afew years back and it was the switch. That positon of the switch burns out for some reason.

[tmoney0501]

were you able to fix it? how?

[87wildside]

Put in a new switch. Thats all.

[Mikz86TA]

Most likely its either a blower relay for the Hi setting or the thermal resistor. 1,2 and 3 positions are on a circuit that uses set resistance to power the fan motor at those speeds. The 4th speed is on its own circuit due to the higher current draw. It has its own relay . I recommend getting the ACDelco parts to repace it with. If you have a multi-meter to test with you can do a couple test to find out where your problem exist. Fisrt since the 1-3 settings work you know your 20A HVAC fuse is good and switch panel is working. From the panel you have a Brown wire to 1 setting, a Tan wire to 2, a LtBlue to 3 and a Orange to Hi or 4. Rotate switch to 4 and verify 12V output from that wire. Ignition must be on FYI. The Orange wire goes directly to the blower relay to pin marked 86. This trips the relay on to supply the motor with a direct hi current 12V source. That source is input on the pin marked 87 and is from the underhood fuse block. The fuse for that is a 30A HVAC which is hot at all times. The relay has output to the blower motor on pin 30 and is a Purple wire. The relay is a standats 30A Bosch style configuration. Pins are 86-Orange(input from Hi switch), 85-Black(Ground),87-Orange(large)(input from 12V underhood f.block),87A-Dk.Blue(Input from resistor to control 1-3 settings) and 30-Purple(Output to fan motor). Fan itself wil have the 12Vinput Purple and Ground Black. Hope this helps. If you need any futher assistance on locations of circuits/help with testing/etc. Just shout at me.

[jdegraeve]

I have a similar problem with my 01 s10. About a year ago i had the same issue with setting 4 not working. I got into a fender bender that required some minimal work to front of my truck. The body shop got everything back together but for some reason after the repair, the electric was not working in the cab. They did a few tests, no fuses blown, etc. etc. Next thing you know everything is back into working order - including the 4 setting on the heater. They never did a thing to repair this, it just started working again! Today, it was pretty cold out when i left work, around 15 degrees. Started my truck and no heater at all, checked fuses in the cab first - all fine. Checked fuses under hood and the 30 Amp HVAC fuse was shot. Replaced it and now the blower works but only on 3 or 4 - nothing on 1 or 2. Any clues on this one?

Could this just be a bad switch as well? What switch are you referring to? The entire front panel of the heater controls?

Thanks for reading.........please let me know, thanks.

[tmoney0501]

im talking about the circular switch on the top of the panel that has four settings

[Mikz86TA]

Probably a bad switch or a combination defective resistor and hi-relay on yours. Refer to my last post for the wiring, colors and what they should test. You need a multimeter. If you test and have strange results, repost them and Ill try to help you diagnose them.I have a similar problem with my 01 s10. About a year ago i had the same issue with setting 4 not working. I got into a fender bender that required some minimal work to front of my truck. The body shop got everything back together but for some reason after the repair, the electric was not working in the cab. They did a few tests, no fuses blown, etc. etc. Next thing you know everything is back into working order - including the 4 setting on the heater. They never did a thing to repair this, it just started working again! Today, it was pretty cold out when i left work, around 15 degrees. Started my truck and no heater at all, checked fuses in the cab first - all fine. Checked fuses under hood and the 30 Amp HVAC fuse was shot. Replaced it and now the blower works but only on 3 or 4 - nothing on 1 or 2. Any clues on this one?

Could this just be a bad switch as well? What switch are you referring to? The entire front panel of the heater controls?

Thanks for reading.........please let me know, thanks.

[Mikz86TA]

Yours seems to be in the high speed circuit alone. Get a multi meter and test the circuits in the last post I did ci=oncerning the issue. It will give you the colors and functions. Likely not the switch but not impossible. Testing is your cheap freind. If you have strange results re-post them and I will try to help you out. 12 Volt Tech - Its what I doim talking about the circular switch on the top of the panel that has four settings

[jdegraeve]

Thanks, i will definitely check this out. Just curious, it seems as though my washer fluid does not operate now, could this be related? It's pretty cold here today like 2 degrees. I checked the outside nozzles and they don't appear to be frozen.....just curious. For now i guess i need to get that heat working, thanks again, i'll try to check it out.

[Mikz86TA]

Hmm- could be the motor. Do you hear it when activating the lever for wash? If you are using water, it might have frozen and damaged the motor pump vane assy. Some washer fluid will freeze but at very low temp. and others are designed not to. Ill check on the wiring and tests and get back this evening on that. Good luck on the heat!Thanks, i will definitely check this out. Just curious, it seems as though my washer fluid does not operate now, could this be related? It's pretty cold here today like 2 degrees. I checked the outside nozzles and they don't appear to be frozen.....just curious. For now i guess i need to get that heat working, thanks again, i'll try to check it out.

[jdegraeve]

No, i don't hear the motor activate when i hit the control for the washer fluid - that certainly concerns me. I haven't looked under the hood yet as i realized this on my way to work this morning. I'm hoping there is a fuse under the hood..........

And no, i'm not using water - using the orange rain-x fluid - for cold weather.

[Mikz86TA]

Si seinor--might be the pump went south. Hopefully its a fuse.

[tmoney0501]

if it is the 30A fuse for my blower motor (the high relay), where would that be? with the rest of them under the dash?

[Mikz86TA]

The fuse for the relay is under the hood at the fuse/relay center on the drivers fenderwell. 30amp Green in color to the RR section of the box. The High relay is located on the firewall under the pas. side wiper cowl area. Should be a OMRON relay and will have distinctive large Orange (12v In) and large Purple (12v out to fan motor when hi is energized) going to it. Check these there for power with meter. Also you can have someone turn high on and off and with your hand on the relay itself you should 'feel' it click on/off. You will also notice for reference that the low speeds resistor is on top of the air-box next to the hi relay--just for reference if you wanted to know. That part only affects the first 3 speeds. Let me know if you need any futher assistance. The locations given are from a 4.3 engine but should be like for a 2.2 engine. TTYL. Michel

[Mikz86TA]

Did you get a chance to track it down?

[tmoney0501]

no, i cant find my fuse box under the hood, would all the fuses be in the one under the dash?

[87wildside]

no, i cant find my fuse box under the hood, would all the fuses be in the one under the dash? The '91s only had fuses under the dash

[tmoney0501]

do you know what fuse it would be then? like gimme a diagram or something

[87wildside]

If it is working in all settings but hi check the red wire from the relay for 12 volts. this wire has a fusible link so if it doesn't show voltage the fusible link is bad. If it reads 12 volts then turn the blower switch to hi with the ignition on and check the orange wire for 12 volts. If no power it would be the switch itself. If both check out ok then you may have a ground problem at the relay.
**note: when checking the fusible link the test light may light then get dim or go out. This means the link is bad. The link are usually located near the starter or altenator**

[Mikz86TA]

Sorry, I was posting answer for the 2nd Gen S-series. The 1st Gen S-series only has fuse box under dash. There is not a specific one foe Hi circuit. That is controled by a direct 12V source and has a fusible link in-line. A fusible link is a black round tube on a wire much like a small glass fuse housing. It does not open and if bad just needs to be replaced. At your Hi relay, which is under the hood close to the rt. side firewall/frnder area, you can check power with a test light or multi-meter. The relay will have 4 wires going to it. One is Black and is the Ground. Another is Orange(fairly large) and is the 12V Battery supply. Should have 12V at all times. Another is Purple(fairly large)and is the output to the fan motor itself. This will have 12V when setting is on High. The other color is sometimes Gray or Green. This wire is from the A/C controls and will have a low current 12V when Hi is selected. First check the Orange for a 12V from the batt. If OK then check also for adequete ground at the Black wire. If OK then see if there is 12V at the purple wire when high is selected(ignition must be on). If Ok, then you have a motor problem. If not move on to check the last wire out. Check for 12V here as well when hi is selected(ignition must be on). If OK, replace relay. If not move on to A/C controls. A/C controls has a single fuse in the underdash fusebox for its power inout. Check that if not already done. If you have gone through all these steps and are still not getting High and have not come up with any of the afformentioned BAD parts, your A/C controller might be bad. Ill go over that test if you reply confirmation all other test have been accomplished. Good Luck, Michelno, i cant find my fuse box under the hood, would all the fuses be in the one under the dash?

[jdegraeve]

When checking these different wires for voltage what am i using as the negative lead? All that has been mentioned in the various posts here is check the orange wire - for example. So what wire(s) do i use the negative probe from the multimeter with?

Thanks.

[Mikz86TA]

Just put the negative M.Meter probe on a sufficient ground. Battery neg if underhood or bare metal or outter ring on lighter socket inside. You are testing voltage so this is the appropriate method.When checking these different wires for voltage what am i using as the negative lead? All that has been mentioned in the various posts here is check the orange wire - for example. So what wire(s) do i use the negative probe from the multimeter with?

Thanks.

[jdegraeve]

Thanks, i will check it out. I really do appreciate your help with this.

[Mikz86TA]

Not a problem at all...Glad to help out anytime I can =) Lemme know what you find out or if you need any futher help. Thanks, i will check it out. I really do appreciate your help with this.

[jdegraeve]

Ok, finally got it. It was a bad resistor, replaced an everything works fine. Thanks for all your help!

Joe


Not a problem at all...Glad to help out anytime I can =) Lemme know what you find out or if you need any futher help.

[Mikz86TA]

Cool deal--glad to hear you accomplished it. Anytime I can help is always a privelidge. Thx, MichelOk, finally got it. It was a bad resistor, replaced an everything works fine. Thanks for all your help!

Joe

[87wildside]

I helped a little...haha

[killerazonic]

OK so i have changed the switch and relay for the blowerfan and it still doesnt work on 4. So im gonna try the resistor. My question is where is it and how much does it cost?

[Mikz86TA]

It is just to the left (lookin at motor) of the valve cover back near firewall on passenger side. Has a 3-4 pin plug, mounted to the A/C housing on firewall, kinda triangular shaped, and should have a couple 7mm screws holding it in. When it comes out it looks like a coil spring on the back. Be sure to check the motor ground too. At low speeds if its a poor connection itll still work but on high the extra current needs a good ground. Hope this helps =)

[killerazonic]

So i went and pulled a resistor out of a junkjard and it still doesnt blow on 4. So can anybody think of anything else it could be?

[Mikz86TA]

blower fan itself or grounding issue at fan?

[tmoney0501]

take it to Acdelco

[jdegraeve]

I've got another question for you relating to electronics in the cab. Ever since i bought my S-10 (2001 2.2L) used two years ago the intermittent wipers do not work correctly. The control arm for the wiper control has the standard 5 intermittent settings then Lo, and Hi. No matter which Inter-setting you put it on the wipers only have one speed about a 1-2 second interval, then they work fine on the Lo and Hi settings. There is just no difference in speed on the intermittent settings. Any ideas on where or how to track this issue down?



Cool deal--glad to hear you accomplished it. Anytime I can help is always a privelidge. Thx, Michel

[Sparky2263]

12V test lights are cheap. Like $5-10.

[Abaddon]

Not to bring up an old thread but I'm curious to see what the solution might be to my problem. My blower doesn't work at all. It was working fine this morning but I parked it during lunch and it won't work at all when I went out to turn the AC back on. It doesn't power up on any setting. When I put the switch on heat or vent, you can hear the vacuum switch over but the blower doesn't come on at all.

Ideas? Should I replace the switch?

[Hammer Head]

no, not yet.. check your fuses. Could even be one under the hood in the fuse/relay box.

[Abaddon]

I checked the one inside under the dash (the heater/AC fuse) earlier and it was fine. I've got a 93 S-10 with a 2.8 6cyl but I don't know about any other fuses that are supposed to be under the hood. I'm still not sure my switch isn't just bad. Any other places to check? Thanks for the input.

[Mikz86TA]

On a 91 you only have the inside fuses. Check them all 1st. Next would be to get a volt-meter or test light. Under the hood is the blower fan on the passenger side firewall. Youll need to start testing there. Blower fan has 2 wires.....one is hot the other is ground. Should test 12v on high and progressively lower volts on the first 3 settings. If nothing at all youll need to check ground. If thats OK, get back and well futher assist you on the next steps to finding the problem source.

[Abaddon]

Already. I tested the cables with my ohm meter and nothing. I turned the key to the on position and I got no reading whatsoever. I'm think it's either the switch inside the truck or the relay. Your thoughts?

Thanks for the help!

[Mikz86TA]

Check all fuses under dash. Check the seperate leads coming from the starter solenoid on the vehicls side of the fusible links and check the relay.

[Abaddon]

I checked the fuses already. How do I check the relay?

[Abaddon]

NM. I went ahead and ordered a relay (only $10 from LMC) and a new heater/AC switch. I can justify the purchase since the truck has been good to me and I want it to continue to do so. That and it's supposed to be 92 degrees here tomorrow and I don't have AC!

[Mikz86TA]

Cool...good luck. FYI the relay has 3-4 pins. It needs either a switched ground circuit and a constant/ignition 12V circuit or a switched 12V circuit and a constant ground to operate. The other 2-3 pins are input from battery or ignition source and on this type of operation(fan relay) it ill be a larger wire. The other wire is the one that goes to the fan/thermal resistor and will also be a larger wire. For your year I am unsure of the exact colors. Most older GMs had a large red, large purple, orange and black going to the relay. If its not working on any slections (hi speed is somewhat seperately controlled from the 3 lower speed settings) then I doubt its the relay. The relay only operates the hi-speed setting due to the large current needed. The lower 3 settings are from 3 seperate wires coming srom the inside switch panel and go to the thermal resistor on the airbox under the hood. The power for the lower 3 settings and the switch panel itself comes via the HTR-A/C fuse (usually a 25amp) in the fuse panel. The power for the relay on the hi-setting is from a Fusible Link which is located off the starter solenoid. Just a little more info in case you stilll have issues after the new parts are installed =)

[Abaddon]

Good info. I appreciate it. It's just too hot to be without AC right now. :)

I'm pretty sure it's the switch because I took it out this afternoon and it practically fell apart in my hands. The selector switch was having trouble moving up and down at all. It was just weird. The AC was working perfectly. I just turned it off because the compressor is loud and I didn't want it to be too noisy when I pulled into a loading dock. I came back out and turned the truck on and nothing in the switch worked. I'm sure I'll be replacing the AC compressor and clutch before too much longer. It's louder than it should be.

One thing at a time, I guess. I may tackle the compressor during the winter months when it doesn't matter how how it is (isn't).

[T Man]

while you are in there installing a new compressor, remember to install a new accumulator, also dont pour oil into the compressor, they have enough (about an ounce) of assembly lube to last them till the oil you poured (i believe the newer systems take 9oz) into the accumulator to make it back around. also flush the system and install a new oriface tube..if your compressor is going tits up, thats the first place junk is gonna get caught up, plus they are cheep. Remember, the compressor should never see liquid..just gas so dont pour your oil in there!

[Abaddon]

That's good advice. I have a 93 S10 so if I decide to do the compressor myself I'll also convert it over to 134a. It's still R12 and it's expensive to charge. I've just been told 134a doesn't cool as quickly as the old R12 does.

[Abaddon]

Got the new switch installed and I am once again riding in the cool! Thanks for the advice, gang. I'm going to install the relay, anyway. It's got 14 years and 162k on it so I might as well just do it as part of my maintenance. It was only $12 after all.

[T Man]

That's good advice. I have a 93 S10 so if I decide to do the compressor myself I'll also convert it over to 134a. It's still R12 and it's expensive to charge. I've just been told 134a doesn't cool as quickly as the old R12 does.

urban legend. This comes from people using the same amount of 134A to charge their R12 system as they used r12. 134 requires more freon as it uses a higher pressure to cool. the new compressor will tell how much is required of each.


Thats a good idea to install a new compressor relay. Everytime your compressor cycles it trips that relay. After time the relay becomes eroded and has more and more resistance. THis is a major problem espcially with fords in compressor failure. If the compressor requires 12 or 14 volts to lock the compressor and it is seeing 11 or less it will lock it more slowly causing it to slip a little bit, think a gradual application as opposed to a slap (which it needs) after a while the clutch will burn out...ive seen a couple of fords come in where the clutch pulley has burnt itself off because of insufficent voltage

[Mikz86TA]

I agree....most of the R143a complaints were only on a car that came with R12 originally and was retrofitted, and usually the complaint was while at idle. So T-Man...what do you think about that Arctic-Freeze additive Interdynamics has out now? Can you just add it with out removing a little of the existing freon and is it really good? Think it can cause more problems in the future / is it a hoax

[T Man]

we use a product out on the market now called Ice 32. It is the only additive recommended by new car manufacturers. I recommend the hell out of the stuff. they claim that it can drop a brand new car, still in the showroom by 5 degrees. It comes in a 12oz can i believe, i usually bleed a little off because an over charged system is as innefective as an undercharged

[Abaddon]

I'm running Freeze 12 in my truck right now because it's compatible with my system and I can get it over the counter. It works quite well. The compressor in my truck has rattled when it kicks in since I bought the thing. I'm not sure it isn't the clutch since it only rattles with the clutch kicks in but since my bro-in-law drove the truck a lot of times without the proper oil and freon (because there's a leak in the system and he was too cheap to fix it, heh) it could be the compressor. Any thoughts on this?

[xacy0303]

I guess I will revive this thread. My a/c, or blower will not work peroid. I checked the fuse and it is good, what I did discover is that there is no power to my heater/ac fuse at all. Will this cause the blower not to work also? I have checked all grounds, and for obviuos broken wires and cant find anything so I think that my problem lies in the fuse block. Also, from the fuse block where does the main power wire run to, and what color is it? Its been like 108 degrees here the last few days so any advice will be GREATLY appreciated.

[Mikz86TA]

If the fuse thats powering the blower doesnt have power, then there ya go.
Id 1st test the blower motor direct to the battery. If it works, then start going down the line with a multimeter testing the circuit and its commponets.

[xacy0303]

Okay, I tested the blower by jumping the relay and it works so I know the blower is good. Also, just testing the a/c,heater fuse I found that it has no power, but when I test it as a ground it shows it to be grounded. Pulled the fuse block down and tested the wire that runs to the a/c, heater fuse and found that it isnt the problem and that the terminal on the block is, because when I test the terminal alone with the wire disconnected it still show that it is a ground somehow. I found a new spot on the fuse block for my a/c, heater fuse and connected the wire but still no fan or a/c? I am tottally confused, what wires should be what on the a/c controls because I am getting nothing from them?