One of the previous owners before me installed an aftermarket switch for the A/C condenser fan (now used as an auxiliary electric radiator fan). The switch did not fit well and it would fall into the dash if I pressed it incorrectly. It also felt of very suspect quality.

So my idea was to use a spare rear wiper switch and install it in a switch slot that was otherwise filled with a plastic blank. 

However, I worry about the amperage rating of the rear wiper switch. The fan pulls 10A max but the rear wiper motor and washer only pull ≈5.4A collectively. Would it be worth it to give it a go? I just don't want to burn out the switch and damage a good OEM part.

Thanks :]

Run a horn relay that handles the current. Have the switch turn the relay on and off.  

Cheers 

Bennie

So as it turns out the previous owner had the same idea as you, Bennie. He wired the cheap switch into the A/C fan relay in the engine bay. Doh!

Well that's good news, less wiring for me to do. 

Does anyone know if these rear wiper switches are illuminated? If so is it illuminated all the time? 

Thanks :]

Edited May 17, 2025May 17 by SuspiciousPizza

Bit of a side question.

For the operation of the A.C. fan the relay is shorted to ground? 

All the thermo switch does is short the relay to ground?

Electronics aren't my thing.

Thanks :]

 

The EA81 AC fan circuit is a satanic unholy mess that includes, among other things, whether the headlights are on.... 

What vehicle are you working on?

 

 

Edited June 8, 2025Jun 8 by bushytails

An '89 GL wagon. The switch was wired to terminal 86 on the AC fan relay (switched to Bosch 5-pin from the original).

This pin, from what I understand, is the relay ground. So all I should be doing when I flip the switch is connecting the relay to ground, thus completing the circuit. 

Sounds about right. You’ll find many circuits on the L series are earth switched. 

If you wire up some driving lights “the normal way” you’ll find your driving lights turn on when the ignition is off and the cab switch that controls them is on. 

Cheers 

Bennie