Heater Switch Bad or Fan???

[DuncanR]

Hey guys!

My heater went out (fan quit). I'm getting about 10 volts in front of the heater switch and the same behind it. I pulled the fan and connected it to the battery and it worked. Battery is about 13 volts.

Where do you think the problem is?

 

[Viperwolf1]

Clean the rust from the fuse clips.

 

[DirtDonk]

Bad heater switch or fan?

Neither one is bad at this point. Sure, they might both be tired and feeling old, but you just measured a low-voltage condition before and after the switch. Nothing wrong with a switch that passes the same exact voltage level through it. And nothing wrong with a fan that works fine when you connect it to the battery.

So basically what Viper said.
You have something that's not letting the full battery voltage make it to the heater switch in the first place. And the first place to look on an old rig like this is always the fuse panel.
Remove and clean the fuses and their contacts, then put them back in. If that does not improve things enough, work your way all the way back to the battery if you need to, to find out where the voltage loss is.

And while you're at it, it's never a bad thing to verify that your body ground is intact. Many of them get removed the first time a battery cable is changed and they don't realize that the clamp holding the ground cable tight to the fender is in fact the body ground.

Good luck. Hopefully it's that simple and you don't have to keep digging.

Paul