Wiring Conundrum. Need advice Please

lal Naja · #1 (**permalink**) 10-03-2011, 11:01 PM

Trying hard to figure out the wiring. I do not understand why the Wiper motor and the Cooling Fan have been wired to the ACC terminal on the Key switch.

From how I read the circuit (see below) the wipers and fan will never turn on unless the switch is in the ACC position.

Can any explain this wiring circuit? See circuit diagram below. Thanks

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Tommy · #2 (**permalink**) 10-04-2011, 04:12 AM

I can't see the image of the wiring diagram.

IndyCobra · #3 (**permalink**) 10-04-2011, 06:03 AM

I can't view your diagram either, but I think the ACC side of the switch is hot when the switch is ON or ACC. So when the ignition is hot, both will operate. They are on ACC so you can also run them when the engine is off.

750hp · #4 (**permalink**) 10-04-2011, 06:41 AM

Murky781 · #5 (**permalink**) 10-04-2011, 03:10 PM

wipers need power after the car is turned off to return to the down position. fans need power to keep cooling if the thermostat calls for it after parking.

lal Naja · #6 (**permalink**) 10-04-2011, 05:46 PM

Tommy & Randy, I hope you can see the diagram now.
Thanks to Craig-750hp for showing it.

And thanks for the input from you all, including Murky781. It prompted me to do a little more research.

First of all the Original key switch that came from Butler had the incorrect key. So I was locked out.

So I went to a auto supply and got what looked like an identical key switch and swapped it out. Now I believe that I have a faulty switch for the following reasons.

1: With the key inserted and in the ON position the Ignition & the Starter terminals are live. This would have been startling and dangerous.

2: ACC is only live when in the ACC position. I agree with you guys that ACC should be live when the key in in the ON position.

I dismantled the original key switch by pulling out the tumbler and was able to do the same test using a screwdriver and the results are: In the ON position, Ignition & ACC are live. Starter only live in Start position.

With regard to wipers & fans. The car would have to have the key in, and in ACC position to operate those two components if that were the case.

My wiper motor has an extra positive feed going to a built-in rotary switch on the motor, and continues to supply power till wipers return to the rest position. The switch is adjustable and shuts off power at the precise moment. If you adjust it correctly that is

The fan is controlled by a nice module from Spal which has a direct feed from the battery + to allow the fan to run it's cool-down cycle. The Spal unit just needs an igition ON/OFF signal and temperature sensor. I'm not going to use the existing wire in my harness. The one from ACC through the fuse > fan (the one I Hi-Lit in blue on the diagram) I'll just save it for some other accessory in the future.

Please chime in if I'm getting any of this wrong.

This Forum is just great! I do not have any local gear head (Petrol head) friends to bounce these issues off. So thanks again to all for your comments.

Arthur

mreid · #7 (**permalink**) 10-04-2011, 09:51 PM

Quote:

Originally Posted by Murky781

wipers need power after the car is turned off to return to the down position. fans need power to keep cooling if the thermostat calls for it after parking.

BAAAAAAHHHP (that's the wrong buzzer).

It's actually backwards and while no one can account for someone elses logic, I'll bet they were deemed devices not required to start the engine. Your key should provide:

ACC: ACC circuits only
OFF: None from key (Only circuits powered by battery have power)
ON: ACC and ON circuits
START: Starting signal to solenoid and ON circuits

This is how your switch should work and it removes power to switched circuits not required to start the car or who may draw battery current away from the starter motor (items like headlights, horn, and brake lights are powered directly from the battery). Fan and wipers are not required to start the engine or for safety.