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Re: Cooling fan not working... Posted by Gary Stottler [Email]  (#1463) [Profile/Gallery]
(more from Gary Stottler) on Mon, 17 Aug 2015 07:15:37
In Reply to: Cooling fan not working..., Brently, Sun, 9 Aug 2015 21:02:10 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Brently,
The circuit has two parts - the signal circuit which is the thermal switch used to turn the relay on and off (so think of it as a wire from 12V, through the switch, through the relay coil, and to ground), and the power circuit which is from the battery through the fuse, to the relay, then from the relay to the fan, then to ground. So, you can try checking for 12V on one of the wires at the thermal switch (signal circuit)and then check for continuity from the thermal switch back to the relay socket. You can try jumping the relay to see if the power circuit is OK, if this works then the problem could be the relay but that's not common. You can try the "fuse roll", sometimes the fuse socket gets corroded (also power circuit). I suspect a problem in the power circuit - 2 things often happen in addition to the fuse issue: One is that the connector from the main harness to the fan pigtail can get corroded (just try unplugging it, inspect, make sure the terminals are clean and tight). The other is that the terminals underneath the fuse panel where the wires connect to the fuse "prongs" get hot and either the terminals corrode or fall off or the rivets through the plastic fuse panel get loose and stop carrying current. Does the fuse area look discolored/distorted from heat? The rivet problem can be fixed by running screws through to replace the rivets. The terminals can be re-tensioned and cleaned.
On my car I have bypassed the whole power circuit from the battery to the relay with modern connectors and fuses. The signal side works fine as is, but I have also added a manual bypass using the "extra" switch on the dash - just grounds the signal circuit and turns on the relay when I hit the switch. Just remember to turn it off - the fan is powered when the ignition is off.
Hope that helps!
Gary
_______________________________________ Gary Stottler
, Fri, 21 Aug 2015 15:00:17, Fri, 11 Sep 2015 11:41:01, Mon, 17 Aug 2015 07:15:37 <-- Viewing This Message
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