Heater Fan

crowebar · September 10, 2008

I have an 05 silverado crew cab with the standard heater controls. I noticed a burning electrical smell the other day and the next thing I knew I had lost the high speed (number 5) on my fan. 1 thru 4 still work great. Any ideas? I did a search and it seems most people had the oposite trouble of high speed only which meant the fan resistor. Could this be the case for me even though I don't have high speed? The other speeds still work perfectly and no more burning smell.

Thanks,

DC

matthuber1 · September 10, 2008

I had the same exact problem on my 2005 - I replaced the resistor.... and i still have the problem. So i am interested in a solution as well.

crowebar · September 10, 2008

That is interesting. I'm hoping because I had a buring electrical smeel for a bit I will be able to see the problem. Maybe it is in the switch???

Any other ideas?

Thanks,

DC

I had the same exact problem on my 2005 - I replaced the resistor.... and i still have the problem. So i am interested in a solution as well.

minibike132 · September 10, 2008

Nine times out of ten on a manual system the problem will be the resistor for loss of high as well as the other speeds being lost. The high blower relay is part of the resistor assembly in a manual. Matt is your truck auto hvac?

crowebar · September 10, 2008

I think you may be right. I haven't pulled it apart yet, but I can hear a click in the fan shroud area when I turn the switch to 5, just no fan. My point is it wouldn't probably make any noise when I turned to 5 it it were the switch itself.

Thanks,

DC

Nine times out of ten on a manual system the problem will be the resistor for loss of high as well as the other speeds being lost. The high blower relay is part of the resistor assembly in a manual. Matt is your truck auto hvac?

biller007 · September 10, 2008

I myself have never seen the resistor cause a problem on High. Only thing I have ever seen is all other speeds quit and High still works. Strange

crowebar · September 10, 2008

I got it.

It was the plug going into the resistor. The red wire on the end apparently wasn't making very good contact and got hot enough to melt the platic on that terminal. The plastic must have acted as an insulator once it cooled. I cleaned it up and tightened up that terminal and everything was great again.

Matt, you might want to look at your plug and see if that is what happened to you too.

Thanks for the help guys!

DC

matthuber1 · September 11, 2008

I got it.
It was the plug going into the resistor. The red wire on the end apparently wasn't making very good contact and got hot enough to melt the platic on that terminal. The plastic must have acted as an insulator once it cooled. I cleaned it up and tightened up that terminal and everything was great again.

Matt, you might want to look at your plug and see if that is what happened to you too.

Thanks for the help guys!

DC

Yup, That is exactly what happened to me... It was weird because it didn't melt the plastic- but the pin was disintegrated, so i didn't notice it when i changed the resistor. Now i need to get creative with a soldering iron....

JA_Silverado_04 · September 20, 2009

This happened to me too. It turned out being the contacts as well. The bad contact was easy to spot. It was all corroded and the wire insulation was even slightly melted. I cleaned the and it worked for few months before it happened again. I have lived with it like this since then, now I've lost speeds 3&4 - so now I'm really going to have to go back in there.

GM inserted the relay to keep the fan control switch from melting on speed 5, now its getting hot after the relay.

Is there any TSB for this Relay/HighSpeed thing?

KENNHON · September 20, 2009

I got it.
It was the plug going into the resistor. The red wire on the end apparently wasn't making very good contact and got hot enough to melt the platic on that terminal. The plastic must have acted as an insulator once it cooled. I cleaned it up and tightened up that terminal and everything was great again.

Matt, you might want to look at your plug and see if that is what happened to you too.

Thanks for the help guys!

DC

Yup, That is exactly what happened to me... It was weird because it didn't melt the plastic- but the pin was disintegrated, so i didn't notice it when i changed the resistor. Now i need to get creative with a soldering iron....

Hey, could any of ya tell me where the 'resistor' is on a '96[c-3500 dually] i only have hih speed---do i have to take out 'climate control switch' in dash? i have 'manual sys. THANX!

patternjockey · September 27, 2009

I had the low end (positions 1-4) go on my 2002 Silverado 2500HD so I came to this forum and searched out the issue. Thanks to your posts I was able to identify the resistor, order the part and installed it myself. The resisitor has changed quite a bit but here is a shot of the failed one.... just removed the lower cover and easily install the replacement part.

Thanks

Dave

JA_Silverado_04 · September 27, 2009

Kennhon....

Mine is a 2004, its right under the dash below the glove box. Mine is a W/T and so I don't have any of the panels underneath and its directly accessible.

I would start by locating your blower motor. Then the blower motor resistor should have a wire that feeds directly to the blower motor. That's how you can find it.

As for my issue:

I ordered a new A/C Delco blower motor resisitor. When I removed the seven pin harness connector pin G (direct power feed for High Speed to the relay) came out and was stuck in the wiring harness.

After much effort I was able to extract the old resistor pin from the wiring harness. Then I found I only got speeds 1,2 and 4 working. I had to file the corrosion off of the contacts on the harness and then I got speeds 1-5 working again.

I didn't like it and now this will not last long, I need a repair harness. I tried the old resistor with some clean up on its connections and now the old one worked on speeds 1-4. Speed 5 not working due to the missing pin.

Anyhow, I'm leaving the old one on there for now. I'm going to order a harness repair kit and then put both new parts in together. Hopefully that will last me a little longer!

KENNHON · October 3, 2009

Kennhon....

Mine is a 2004, its right under the dash below the glove box. Mine is a W/T and so I don't have any of the panels underneath and its directly accessible.

I would start by locating your blower motor. Then the blower motor resistor should have a wire that feeds directly to the blower motor. That's how you can find it.

As for my issue:

I ordered a new A/C Delco blower motor resisitor. When I removed the seven pin harness connector pin G (direct power feed for High Speed to the relay) came out and was stuck in the wiring harness.

After much effort I was able to extract the old resistor pin from the wiring harness. Then I found I only got speeds 1,2 and 4 working. I had to file the corrosion off of the contacts on the harness and then I got speeds 1-5 working again.

I didn't like it and now this will not last long, I need a repair harness. I tried the old resistor with some clean up on its connections and now the old one worked on speeds 1-4. Speed 5 not working due to the missing pin.

Anyhow, I'm leaving the old one on there for now. I'm going to order a harness repair kit and then put both new parts in together. Hopefully that will last me a little longer!

Thank you Sir... getting to blower was NO problem[after 134,000 miles my blowermade more noise than the locomotive i used to run!] Got a real AC/Delco motor--- followed purple hot wire[used Haynes' manual to show how and why the resistor works in series[i'm NOT a big fan of this manual-bought assembly manual on ebay yesterday]. And, Yes, Virginny, voila!--- all speeds! Thanks to all here!