what size diode?

[jfever71]

What size diode should i put in the wire going to a temp switch to turn on my electric fans. I keep burning out switchs and i think if I put diode in the wire it will stop the ground going to the switch and burning up. I just have no idea what size to put in.

Over the winter i went four five months without any problems but soon i started using the air conditioning the switch started burning up.

 

[Ruger_556]

Are you burning out a temp switch or a toggle? It's a motor not a solenoid so you shouldn't need spike suppression in the circuit... If you're not running a relay you need to. Then use the temp switch to control the relay.

 

[Ruger_556]

Then make sure you use a relay with a diode built in (spike suppression) because the relay will spike when it cycles off.

 

[jfever71]

I have the negative coming off the temp switch running to two relays, one for each fan. And I have the negative off the a/c tapped into the wire running from the temp switch to the the relays. It seems like if I don't turn the a/c on the system runs fine but soon as I run the a/c for awhile the switch will go bad, because the fan will not shut off. I was going to put a diode in the wire between the switch and were the a/c wire is tapped in. I was thinking that when the a/c is on for awhile it over heats the temp switch and burns out.

And I also have one relay for a manual switch to turn on the fans.

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