'95 Heater Fan Issues

[special-K]

This is on my '95 K2500 Suburban. Late last winter the fan control started acting up. Some positions wouldn't always work. It seemed pretty random and if I switched around sometimes I'd get which ever setting I needed. If I remember correctly, it may have also acted funny for switching from defrost to heat and messing with the fan switch could help. Like it wouldn't switch while fan was on High, but would if on Low. I'm not sure now, after all these monthes, so let's just stick to the fan control issue for now... Unless someone is certain this is all inter-related.

Now that the mornings have been cool enough to want a little heat and more rain creating the need to defog windshield I have not been able to get any fan at all. I get the heat. I set the controls to defrost mostly since keeping windshield clear is mostly what I've needed and it isn't cold toes time yet. I definitely have defrost but need to check to see if heat switches to under dash outlets. Right now what most concerns me is getting some fan action. From what I have learned, I don't believe the issue is the control module, but open to better advice. Could what I described be a symptom of a failing fan switch? Any help appreciated. It seems the options for simple replacements are heater control module, fan switch, or whole control panel.

[sntrym95]

There is also a resistor on top of the airbox behind the glove box. The resistor controls the 3 low settings while the high setting goes straight to the blower motor. I would get out the multimeter and pull the wires from the fan. Switch the fan on at the control for each setting, and check the voltage at the fan. Full high should be 12-14v. If my memory serves me correctly, the low settings are 3v, 6v, 9v. If any of these are off and high works fine, I would suggest the resistor. If none of them provides voltage, then it's likely the switch/control panel. If all of them work, then go for the blower motor.

[sntrym95]

another couple things to check - on the wiring to the blower motor there is a connector. Mine melted at one point and created a little random issue. It's up behind the glove box.

Check your body grounds too. Add another to the blower motor to help. They rust out sometimes.

[special-K]

Thanks for the suggestions. I ordered just the switch to begin with. I'll go over all connections.

[Tom]

Its the switch. I go threw one every 2yrs or so. Used to replace the control panel, then realized the switch can be done by itself for 1/10th the cost.

[b454rat]

Crap part is its 95 only. Dunno what the difference is but there is. The fan in my 96 Yukon was on hi in any position but hi, it would turn off in hi. None of the vent settings changed either. Was a mix between floor and defrost. Got super lucky and found a brand new one in the junkyard. Grabbed the door blend motor for the hell of it. Now everything works!!! But now motor that I just put in last year has a knock. Maybe the truck is cursed, maybe it's the whipple, but I didn't drive it that hard....

[special-K]

I got the switch and the module just in case. I also have wanky wiper action. They have become very independent minded, turn off when they are good and ready, when I hit them for a single swipe they may sweep a random number of times, might not park all the way, go on full-time when I'm on intermittent. I do have wipers, but they sure do act funny. I got that module, too. That is an easy fix. So today is the day.

One evening after work I thought I'd "pop" that heater fan switch in real quick before going inside. Had a little bit of daylight left. The dash surround is all munged up from the county sheriffs (p.o) yanking all their equipment, so removing that takes a minute. I go to pop the tabs on the control panel and soon as I touch them (yes, carefully) I hear all this shattering plastic. I hadn't even pried yet! Those things snapped off and so did the shaft on the fan switch. I didn't even touch that. I decided to wait till today to mess with it. That plastic was way brittle, unbelievable. I'm hoping the panel will still sit in there ok behind the surround. But I may be ordering the whole deal now. The 'Burb came with basic AM/FM and I now have the factory AM/FM/Cass/CD to swap in... hopefully... today. get all this sorted out and I'll see about finding a good surround. Then there is the steering wheel with a chunk missing at 1:00 ever since I bought it. I have a really nice upgrade factory wheel to replace it with.

[Grumpy old man]

I've got the same 2 issues with my 95 K2500 the control module started acting funny last year and I put off buying a new one because of my 67 build parts wish list , last year the module was $165.00 new and checking for one last week they are no longer made I found one online for $453.00 and ebay had one seller at $743.00 . There's a youtube video on how to use the later module and the wiring off the old one but I haven't gone into it all yet .

[PDW HOTRODS]

I have a 99 Suburban and I have had to change the heater fan switch 3 times. The new one's are junk. They last a few months and start going out. Last time I also added a hot wire with toggle switch direct to the fan for a back up. When the switch goes out again I use the toggle switch and still have a fan. Does anyone know of a brand switch that will keep working?

[sntrym95]

Your best bet is an original if you can find it. eBay has some for a couple hundred. the aftermarket ones are hit and miss as they use inferior materials and don't last as you've found.

[68 TT]

Originally Posted by PDW HOTRODS

Does anyone know of a brand switch that will keep working?

Not the one I got from AutoZone as their house brand. Warranty or not it isn't worth it considering the work involved in replacing them and inconvenience. I went through three in under a year in my old 1995 K3500.

[Grumpy old man]

I found one on Ebay for $109.00 with a warranty for my 95 and also replaced the blower motor resistor from auto zone for $25.00 and it all works again . The wiper issue was fixed with a little re soldering and works as new again .

https://www.autozone.com/cooling-hea...776/384856_0_0

https://www.youtube.com/watch?v=U3H7UKEC-rU

The (1995 only) control panel ebay seller was macsusedcars0 he said he had more

[Grumpy old man]

seller https://www.ebay.com/itm/1995-Chevy-...rdt=true&rt=nc

[special-K]

So if I buy a complete panel like that it has to be '95? I see yours was listed that way but all the others on Ebay say 95-99. I assume they are wrong. I know '95s have some one year stuff but I don't know what

[Grumpy old man]

Yup . It has to be a 95 control module , I'll post a picture of the one I took out and you can see the different harness in the back , As if I didn't have enough one year only parts on the 67's now my 95 GMC is a one year only truck too .

This pic is off the ebay post but if you look at the top left there are 2 plug ins for the wiring harness and a rear defrost button .

[sntrym95]

I bought one off eBay some years ago that was for 95-99. It came with a adapter harness for the 95 but had the plugs for the later years.

[Grumpy old man]

Originally Posted by sntrym95

another couple things to check - on the wiring to the blower motor there is a connector. Mine melted at one point and created a little random issue. It's up behind the glove box.

Check your body grounds too. Add another to the blower motor to help. They rust out sometimes.

Does anyone have the climate control wiring schematic ? specifically the ground wire connection points ? The more I think about this it seems to me the ground wires could be causing these symptoms ? and by tying in another ground wire into the existing ground plug close to the fan motor just might clear up the problem ?

[sntrym95]

Originally Posted by Grumpy old man

Does anyone have the climate control wiring schematic ? specifically the ground wire connection points ? The more I think about this it seems to me the ground wires could be causing these symptoms ? and by tying in another ground wire into the existing ground plug close to the fan motor just might clear up the problem ?

From some troubleshooting a while back. http://www.flickr.com/photos/99167717@N06/