Both fans stopped working?
Thread Starter
Heel & Toe
Joined: May 2015
Posts: 15
Likes: 0
Both fans stopped working?
I have a 1987 z52 auto coupe. Normally the main fan turns on when the ignition is turned on, shuts off when the engine fires up, and then turns back on when the sensor tells it to (228?). Yesterday, I was driving around town with outside temps of about 90*F. Car was operating at normal temps 180-210. I then rolled up the Windows and turned on the a.c. (c68). After about 5 minutes, I noticed the temp getting a little too high for my comfort. Thankfully this was right as I was pulling in to my driveway. As I pulled in and shut the car off, temps were about 240, and I monitored them up to 248 on the dash until it started falling. Once the car cooled off, I restarted it. Started and ran fine, but I noticed neither fan worked. With either the ignition on, or engaging the ac, I coudent get either fan to work. I just bought the car, so I don't even know if the aux pusher fan works, but I know the main fan worked. Now I don't really know what to do. The fan fuse is good, and the relay clicks when I turn the ignition, but neither fan works. Any ideas? Thanks in advance.
Race Director
Joined: Apr 2002
Posts: 10,036
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From: Anaheim CA
You can test the auxiliary fan (the one in front of the A/C condenser) by shorting the green wire on the coolant temperature switch to ground. Unplug the connector and short the pin to a convenient engine part. I use the alternator bolts. This wire:
The main coolant fan should come on if you turn on the A/C (engine running). The system must be charged with freon so the high pressure switch functions. You can test this by unplugging the coolant fan cycling switch (the smaller switch on the left), which simulates having the A/C on:
The main coolant fan should come on if you turn on the A/C (engine running). The system must be charged with freon so the high pressure switch functions. You can test this by unplugging the coolant fan cycling switch (the smaller switch on the left), which simulates having the A/C on:
Last edited by Cliff Harris; Aug 6, 2015 at 12:52 AM.
Thread Starter
Heel & Toe
Joined: May 2015
Posts: 15
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Alright, I got the aux fan to work by grounding it to the alternator bolt as suggested. Looks like I need a new aux fan connector though, the plastic connector where the aux fan wire connects to the sensor on the engine is in pieces, and Dosent hold the pin. The main fan I still cannot get to work. I have done most of the trouble shooting in the Haynes manual, but nothing. When I turn the ignition, I hear a loud click that sounds like it's coming from the main fan motor. The fan spins freely, so it's not jammed. Maybe I need a new fan motor? Thanks for the help so far, it has been very useful.
Thread Starter
Heel & Toe
Joined: May 2015
Posts: 15
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Brought the car to my mechanic on Monday. Got a new connector for the aux fan to get that working. Turns out, I needed a new fan motor for the main fan. Got that all done, and now no problems. I have noticed that the main fan stays on all the time now though. I am thinking the thermostat is stuck open and i will probably get a new one.
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
Your car might be wired to run the fan all the time (some people do that because they think their car is "too hot"). Another possibility is that the coolant fan cycling switch on the A/C line is bad or there is a bad connection there (see my second picture in post #2).
