Currently the auxiliary fan on my street rod is controlled by an off/on, 3 pole, switch located under the dash. I have an extra automatic, probe activated, relay that I want to install. I have had the tested the relay outside the vehicle and it is good to go. When I tested it in the vehicle I blew the fuze. Maybe I just touched something I shouldn't have...I don't know. Attached is a diagram of how I intend to wire it. Does anyone see anything wrong with the wiring diagram?
Thanks......as I indicated I am using a relay...so on the diagram you can consider the yellow circle marked "Fan" as the relay. I just can't figure out what I might have done to make the fuze blow.
Is that really a relay or is it a capillary switch? A relay would require additional power and control wires. The capillary switch simply used a temp probe to heat up the fluid in the capillary tube. The fluid expands and closes the switch. The way you have it drawn suggests it is really a capillary switch. If so, temporarily disconnect the on/off switch and see if the fan comes on with the capillary switch. If so, you've got a problem with the on/off switch or wiring to it.
Here is a copy of Vintage Air's suggestion of how to Wire a Relay for Fan usage (hope this helps)-
There could be more than one reason why your Fuse popped (too small of Fuse, too small of Wire, Switch not rated correctly, etc.)-
I just finished wiring my Fans (I have 5 Fans in my Car ain, and I hate that I have to run a separate Fuse and either buy a Relay socket (or wire it all together-yes, I am lazy) for each one, so I will offer an alternative:
I have used these all over my Car (and love them)-it's basically an all-in-one Relay, and he offers them in different Amperages (I used his 70 Amp double units mostly)-he uses Industrial Relays and J-Case Fuses-
I think we all need to go back and look closely at the diagram in the OP's first post. The thing he calls a "relay" with a temp probe does not appear to be an electrical relay. It is a mechanically actuated thermal switch.
I agree with Joe, looks like a temp controller as a relay would have a separate pwr source to control it's "On-Off" state.
Here's how I suggest you wire it. You need the fan to be in the "On" state whenever the engine is running..... switched 12 volts controlling the relay. Very expensive lesson for me when I forgot to turn on a toggle, engine over heated and warped the intake. I also install a bypass switch as a backup etc.....
The capillary thermal switch doesn't need a relay. It is designed to carry the current from the fan motor. The OP's initial drawing shows that he has power full time power to the capillary switch, then from there to the fan. That's why I suggested disconnecting the manual switch as a test. If the capillary switch turns the fan off and on as intended, then it (and the associated wiring) is correct and the problem is in the manual switch. Note that the only reason why the manual switch has a ground wire is for the indicator light in the switch. That is really a DPST switch. One pole is supposed to power the fan, the other powers the indicator light. The switch he's using is internally wired like this:
including one a few pages down that uses a braking relay that slows or stops the fans from windmilling in the ram air thru the radiator.
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