IHADAV8.com - Turbo Buick Tech, and Nonsense

Tech Area => General Buick Tech => Topic started by: Scoobum on July 08 2015, 10:35:34 AM

Title: Cooling Fan Problem
Post by: Scoobum on July 08 2015, 10:35:34 AM
I forgot to mention the TR from the track last week has the cooling fan come on as soon as you key it...hot or cold. I checked Steves site but didn't see a cause for that issue. Anyone?

P.S. It does shut off a couple of minutes after you key it off on shutdown.
Title: Re: Cooling Fan Problem
Post by: motorhead on July 08 2015, 11:02:27 AM
If I had to guess the cooling fan temp switch is fragged.

http://www.gnttype.org/techarea/images/wiring_images/cooling_fan_circuit.jpg (http://www.gnttype.org/techarea/images/wiring_images/cooling_fan_circuit.jpg)
Title: Re: Cooling Fan Problem
Post by: dyermullet on July 08 2015, 12:14:06 PM
First thing get rid of the off delay relay.  When it fails it drains your battery dead.  Just unplug it it will not interfear with low or high speed fan operation.
From reviewing the drawing, the off delay relay could be causing your fan to be on, the high pressure AC switch could be stuck closed, the high temp switch on the intake could be stuck closed, any of the three relays could be stuck closed, or you have a ground signal to a relay coil that is shorted to ground causing the relay to close.
Unplug the off delay relay first and then test.
If still have problem unplug AC high pressure switch
If still have problem unplug one at a time high speed relay, then low speed relay.  Findout which one is causing the fan to run then you can test further.
 
Title: Re: Cooling Fan Problem
Post by: Scoobum on July 08 2015, 01:31:27 PM
Thanks so much for the help guys. Car comes into the shop next Sunday for valve springs...and I'll try to nail it down then. :cheers:
Title: Cooling Fan Problem
Post by: Steve Wood on July 08 2015, 05:48:01 PM
http://www.vortexbuicks-etc.com/fan.htm

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Title: Re: Cooling Fan Problem
Post by: Top Speed on July 09 2015, 03:49:46 PM
Thanks Steve.  I still have to figure out why my fans don't work right.  One day I will get the Buick out and actually work on it!
Title: Re: Cooling Fan Problem
Post by: good2win22 on July 09 2015, 04:22:48 PM
Good info.  My delay relay is still functional but looks like I'll be disconnecting it.
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