: Heat fan not functioning



Nomadinator
01-19-10, 05:50 AM
Hello folks,

I am trying to help my father troubleshoot his 1980 Deville (with 40k miles) due to a AC / Heat fan not functioning. I scanned through many of the previous posts on this forum, but none seemed to match exactly, so I figured I would ask the experts.

Many of the threads pointed to the controller which I am assuming is the multi-plug connector on the firewall in the air box next to the fan.

The fuse is good but we do not have power going to the fan. When switching the lever from "Auto" to any other position, you can hear the vacuum operated dampers functioning.

The fan will not work on any setting at all.

Any help would be greatly appreciated. I checked eBay for a factory service manual, but came up empty handed.

Thanks much!

Alan

thefleetwoodguy
01-19-10, 09:13 AM
blower motor resistor

Nomadinator
01-20-10, 04:21 AM
Thanks!

I will see if I can trace the wire back to find it. Are they under the dash or on the firewall?

Thanks again.

carnut
01-20-10, 02:51 PM
Look under the dash below the steering wheel. Should be a bank of relays in a common block. The fan relay melts within the connector bank. Orange wire I believe? If you find it melted, replace the relay and cut the wires to it out of the common block and wire them directly to the relay. Another place it can melt is behind the climate control display. Pull that from the dash and inspect the multi wire plug connected to it. It can melt there as well. Clean the copper connector on the control head, cut the wire out of the plug and connect it directly to the climate control head as well. Very common problem. Years of people changing the temp wheel from max cold to max heat causing surges which eventually melt the plugs.

carnut
01-20-10, 02:52 PM
Look under the dash below the steering wheel. Should be a bank of relays in a common block. The fan relay melts within the connector bank. Orange wire I believe? If you find it melted, replace the relay and cut the wires to it out of the common block and wire them directly to the relay. Another place it can melt is behind the climate control display. Pull that from the dash and inspect the multi wire plug connected to it. It can melt there as well. Clean the copper connector on the control head, cut the wire out of the plug and connect it directly to the climate control head as well. Very common problem. Years of people changing the temp wheel from max cold to max heat causing surges which eventually melt the plugs.

carnut
01-20-10, 04:34 PM
Sorry, I double posted. When I hit post quick reply the web site did not confirm right away?

durrk johnson
01-21-10, 01:29 AM
If Im not mistaken, this might be the part you need.

http://www.autozone.com/autozone/catalog/parts/partsProduct.jsp?itemIdentifier=156224_0_11245_&skuDescription=Duralast+/+Relay+-+Blower+Motor&brandName=Duralast&displayName=Relay+-+Blower+Motor&categoryNValue=15299999&sortType=&store=1985&isSearchByPartNumber=false&fromWhere=&fromString=search&counter=0&itemId=607-0&navValue=15200607&filterByKeyWord=blower+relay&productId=156224&searchText=blower+relay&categoryDisplayName=Climate+Control&parentId=52-0


I had the same problem when I had my 80' CDV.


It was the blower motor relay. Simply replacing it fixed the problem, but I eventually went through a couple of them and never found out the true problem. They burnt out again in a about a month of use if there is someting else wrong.

Nomadinator
01-21-10, 05:46 AM
Thanks for all of your replies guys.

This will give me a good starting point.

Thanks!