Heater switch

Can someone tell me if the stock heater switch is designed to spring to off?
So to run the heat or defrost you have to keep your finger on the switch.


Nope the stock heater switch flips in and stays on! Your switch must be broken. I’m sure you can find a replacment switch at most auto parts store

The GEM heater switch is a specialty item and scarce as hens teeth. Also expensive.

Takes some changing to replace it with a commonly available automotive switch.

I’ll trade you ten heater switches for one GEM factory AC switch…


Is there any way I can get a pic or diagram of how the switch should be wired. I think the previous owner might have messed with it.


The heater is only 2 wires. The switch simply connects 2 wires.

The switch that’s on my lower dash is a common everyday switch Unless it’s 72 volt ???

There 8 spades with a couple jumpers on the back. Does anyone have a pic or diagram of the correct wiring?

It’s not an ordinary switch (0106-00595 ASSY, HEATER CONTROL SWITCH) and has been a PITA for owners since day one. If you want to do a little updating and are electrically handy I have a PDF of the electrical diagram for a 2005 which has a simple circuit. Email me rodneyadiehl@aol.com

Could someone post a picture?

I’m missing something.

Oh, I get it! Doh. The 2005 is the simple one.

Here is the 2005 with relay.
And a 30 amp switch without relay.

I could draw a switch and bosch relay with numbers if it was helpful.

Note blower motor is off the 12Volt Buss

Heater coil is off the 72volt buss

We saw this happen once. We were living in Tuscaloosa.

[quote=OLD HOUSEBOATER;27054]Note blower motor is off the 12Volt Buss

Heater coil is off the 72volt buss[/quote]

I’ll change it to reflect that.
Or delete it if not helpful.
May be hard to find a switch rated 72vdc at >30a.
Digikey has one but it’s $25:eek:

Believe me $25 is cheap!

You might help these guys out with source and switch #

The only down side to not using the relay circuit is if you have blower circuit failure you could have a fire.

Correct, same goes for the relay circuit though.

Unless there is a high temperature limit in the heater that cuts power to relay if over heated.

I didn’t see one in diagram. I could be part of the element. I bet one out of a clothes dryer would work.

If you think a toggle switch properly rated would work, I’ll post a link.

I will work

My bad!

The dc rating was off the screen.:o
I just saw the 125 volt rating.

Yeah DC is a toughy and were back to requiring the relay

Is this the part? #12

The ugly switch is the only one found so far with a 125vdc 20A rating.:o