Fan problem
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2nd Gear
Joined: Jun 2014
Posts: 2
Likes: 0
Fan problem
Fired up the car this spring and noticed that the fan runs continously from a cold start. Looked at the schematic in the shop manual and it appears that when the fan relay is pulled low the fan is enabled. I disconnected the temp sensor and the line is still being held low. The schematic shows one more connection going off the page to AC which I can't seem to find anywhere else. I did convert the AC last fall from R12 to R134a and it seems to work OK. Any ideas on how the AC might be holding the fan relay control line low?
Intermediate
Joined: Apr 2012
Posts: 37
Likes: 0
From: Pittsburgh PA
My fan on my '84 was also running continuously since someone hot wired it from the fuse box-finally decided to fix it -replaced relay and fan switch that looks like a coolant sensor (screws in to head between last two plugs on passenger side). Fan sensor was broken-that was problem-I also replaced relay , too since it was only $7.99 at parts store-anyways, works like it's supposed to now. I think someone broke the tip off the sensor when they were changing plugs and didn't realize it.
Safety Car
Joined: Aug 2009
Posts: 3,752
Likes: 278
From: Melbourne, Victoria, Australia
Hi look along the small a/c pipe that goes to the evaporator box, there are 2x pressure switches 1x has plain spade terminals that is the a/c high pressure lock out, the other pressure switch with the round connector on it is the pressure switch that the ECM senses to run the cooling fan, open = a/c call make sure it is plugged in fully.
Removing that connector will make the ecm start the cooling fan.
Removing that connector will make the ecm start the cooling fan.
Burning Brakes
Joined: Feb 2013
Posts: 1,173
Likes: 152
From: norway
