I have a 1980 vette. all of the sudden my heater fan and wipers only work with the drivers door open. or swith open. if I push the switch in, they stop working. when I let off, they start right up.??????

 

You have lost a ground somewhere, most likely the one under the dash on the left side.

 

I did check as many grounds as I could find including the one under dash on door jam. Even reset door switch after a good cleaning.

 

Is it possible that there are more then one ground under the dash? I put a new printed circuit on the panel and everything seems to work but the fan and wipers. They work but only when the door switch is open. I know that something must be shorted out, but im not finding it.

 

2 threads?
not really appropriate.

start at the wipers.
seems people like to make custom grounds there.

 

SIMPLE... The SAME GROUND WIRE is used to run your wiper and blower motor.

And ODDLY enough...the alarm switch on your firewall has wiring that connects to your door jamb switches.

So...someone has accidentally attached the ground wire for your blower motor and wipers to THAT wire...which is why they work when you open your door due to the circuit is being completed.

The correct ground wire will be a wire that attaches to your lower bellhousing bolt on the right side of your engine down by the starter.

KEEP IN MIND that the wiring harness from your starter.... runs up the backside of the engine and connects to a connector in the MAIN wiring harness for your engine just behind your right valve cover. This connector will be able to have 6 wires in it and all the ports may not be used. AND if I am not mistaken. The ground wire for your blower motor and wipers is IN this connector.

AND what could have happened...because it is NOT uncommon is that the connection got messed up so someone decided to run the ground to another wire.. And with the hood up...those wires at your alarm switch on the firewall would show to be a ground at that time....but it would NOT be a ground when the hood is shut or the doors are shut.

Also be aware due to many people screw this up.. the BLACK wire that is your ground for the blower/wiper...is often times attached to the 12 volt positive stud on the solenoid....which will make it so the blower/wiper will not work. The reason for this mistake is that the eyelet for the black ground wire is large enough to go on the stud and it is in the same area and people do not pay attention when they take stuff apart.

DUB

 

That sounds right. Common issue. I posted too fast. Dub is correct.

 

sorry about the 2 threads. Just started here and didn't realize it was a different thread.

 

dub you are absolutely correct. I traced the ground on the starter and found it broken. Problem solved. Y'all please forgive my ignorance on how these forums work. Just trying to figure it all out. I'm old school. Pencil and paper. Cups with strings and the like. Thanks guys. Love this car.

 

welcome

many times info and advice get lost between more than one thread.

i pointed you to the area, Dub broke it down for you.

glad it is fixed.

a plastic car lives with good, proper grounding.

 

Thanks for the knowledge. I've had this old girl for along time with no problems. Recently had two new cats welded in thanks to Colorado law, and I believe that's where the ground got broke. Haven't drove it thru the winter so I didn't catch it. Feels good to have it right though. Bless yall.

 

I am glad that my comment/suggestion was of some help for your problem and getting it repaired.

DUB