Fans
Thread Starter
Instructor
Joined: Oct 2003
Posts: 117
Likes: 0
From: Coweta OK
Fans
Since it has started warming up I noticed my cooling fans were not working. After replacing both relays the main fan (between engine and radiator) comes on at 225 degrees. Shouldn't it come on at a lower temp?
The fan in front of the radiator won't come on. I checked the fan and it works. Any ideas where I should look for the problem.?
The fan in front of the radiator won't come on. I checked the fan and it works. Any ideas where I should look for the problem.?
Pro
Joined: Jun 2003
Posts: 559
Likes: 6
From: OKC OK
Re: Fans (VettBrat)
That sounds about right for the primary fan. If memory serves I think it's calibrated to come on at 230. You can change that with a chip mod. The aux fan should come on with the a/c though mine doesn't either. There is a temp switch (not sender) in one of the heads (depends on the year for which one/side). To make sure whether it's the switch for the fan or the sender for the temp guage turn the ignition on and ground one of the leads. Either the fan will come on for the switch or the temp guage will read 299 for the sender.
MAD sells a switch calibrated to close at a lower temp (on 200*/ off 185*) part # 609-106 $12.99. I use this as well and wired in a manual switch. :seeya
MAD sells a switch calibrated to close at a lower temp (on 200*/ off 185*) part # 609-106 $12.99. I use this as well and wired in a manual switch. :seeya
Le Mans Master
Joined: Oct 2003
Posts: 6,130
Likes: 2
From: seattle WA
Re: Fans (MtlSphere)
I got the 200 on 185 off and took the two wire from the new switch directly to the primary fan relay-causing both fans to come on at the same time, rather than taking one wire to each relay- I like it, don't think I would like the manual switch-I can get awful forgetful at times :D
Le Mans Master
Joined: Dec 2000
Posts: 7,839
Likes: 22
From: San Diego, Ca
Re: Fans (VettBrat)
Up until '90, aux fan is independent of a/c operation. It's grounded by a switch in the right or left head, depending on year, at 228. Main fan is controlled by the ECM based on temp signal of 226 from the Engine Coolant Temp switch, or 230psi signal from the a/c fan switch. If under control of the a/c switch, it will shut off when the pressure drops to about 170 - 190 psi.
