Fan not coming on automatically but works with ac
11-09-2011, 09:50 PM
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Car: 1986 Z28 Camaro
Engine: 350 with .440" lopey cam
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Fan not coming on automatically but works with ac
I just got a new engine and having a few problems (another post about carb issues over in the carb thread).
One of the issues I'm having is the fan is not coming on with a brand new fan switch in the new engine.
It comes on fine with the AC turned on, but will not come on by itself. Disconnected the fan relay to see if that might the problem, thinking that maybe the relay only worked off the switch and not the ac, but it wont come on with ac either if the relay is disconnected. I'm assuming that means the relay is fine.
Anyone have any other ideas on what else might be causing this, seems like it should be a rather simple circuit but for some reason it just isn't working. I don't really want to wire the fan to run all the time if I can avoid it.
One of the issues I'm having is the fan is not coming on with a brand new fan switch in the new engine.
It comes on fine with the AC turned on, but will not come on by itself. Disconnected the fan relay to see if that might the problem, thinking that maybe the relay only worked off the switch and not the ac, but it wont come on with ac either if the relay is disconnected. I'm assuming that means the relay is fine.
Anyone have any other ideas on what else might be causing this, seems like it should be a rather simple circuit but for some reason it just isn't working. I don't really want to wire the fan to run all the time if I can avoid it.
11-09-2011, 11:32 PM
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Re: Fan not coming on automatically but works with ac
the fans come on automaticly when you turn on the ac. this tells you the relay is working and so are the fans. I would look into the temp switch as the culprit. do you have a single fan or a dual?
11-10-2011, 12:37 AM
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Re: Fan not coming on automatically but works with ac
If you installed a new fan switch, then possibly it's the wire going to the relay that's not completing the ground to that relay. With the key on try grounding the wire from the switch and see if that works. If not there is a break somewhere in the wire or the connector has a problem
11-10-2011, 12:39 AM
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Car: 82 Z28
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Re: Fan not coming on automatically but works with ac
If fan runs; new switch is bad.
If fan doesn't run ;
then you have a problem with the relay control wire from relay to switch.
Temp run a wire between the 2 points and see if fan runs to confirm.
http://austinthirdgen.org/mkportal/m...ine_wiring.gif
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