Rear Heater Freaking Out

For some reason, my rear heat is acting possessed. If you turn it on to the lowest setting, it will either not blow, or blow full. I suspect a bad switch. Anybody have a clue where and how to replace it?

Also....it seems to effect the entire vehicle. When the rear heat is acting up, it affects the lights, instrument panel, etc. You can hear the relay click every time it adjusts on it's own as well.

Finally, I am also having trouble with the battery not charging. It's a brand new battery, with a brand new alternator. Could this switch be the source of my current draw?

Thanks,

For some reason, my rear heat is acting possessed. If you turn it on to the lowest setting, it will either not blow, or blow full. I suspect a bad switch. Anybody have a clue where and how to replace it?

Also....it seems to effect the entire vehicle. When the rear heat is acting up, it affects the lights, instrument panel, etc. You can hear the relay click every time it adjusts on it's own as well.

Finally, I am also having trouble with the battery not charging. It's a brand new battery, with a brand new alternator. Could this switch be the source of my current draw?

Thanks,
Hello

I would feel the relays under the dash and find the one that's clicking. This relay may not have anything to do with the heater??

Have you checked to see if the Alt is charging? Put a volt/ohm meter on the cables with the engine running. You should see above 13 volts. If not the alt isn't charging. Also, many auto parts stors will do this test free of charge hoping that you will buy parts from them. There also could be a "draw" on the battery and it's draining the battery when the engine isn't running.

Regards

Dan

Check the alternator fuse.....on my '96... It is fuse "T" in the engine compartment fuse / relay box.
If that fuse is Open.....the alternator will not charge the battery. You can buy replacement fuses at any auto parts stores. Fuse "T" is one of the "mini" fuses.

Same thing happened to me with my 99 Windstar. Turned out to be a failed body control module which is pretty much one of the brains for the Windstar.

I hear so many that replace their alternators frequently because te pipeline of supply is just trash. Much better results finding a rebuild shop for the original for about $50. I would attach a DMM to the battery and start the car. You should get about 14.3V at idle without any power attachments and a drop to 13V and change with all power - lights, AC, full fan, and rear defrost. It will then jump back to 14.3 when you rev the engine. That's a good alternator load check.

If that's all good, I've not heard of any fan switch causing havoc. These machines do strange things when their batteries get low, considering all the computer control. You'll likely find the culprit in the charging system.
Good luck!
Marc/Atlanta