Electrical Gremlin

[G.R.]

This has just started happening on our SPF when the lights are switched on the wipers make one sweep and if the hi-beams are switched on again one sweep of the wiper.

Is this possibly a faulty ground somewhere? It sure doesn't make sense to me

Thanks in advance any suggestions would be helpful

[petek]

Might be a bad ground on the wiper motor or it might be some sort of weird short or miswire to the wiper motor.

I'm guessing that the wiper motor, while sitting in it's park position, is receiving a brief surge of electrical juice on either the slow or fast terminal. All it would need is the briefest burst of energy to cause the motor to rotate ever so slightly off of the park position. Once the motor has spun off of the park position the motor would continue to rotate until it came to a rest in park once again.

Try putting a voltmeter (analog would be best in this case) from the ground on the motor to the slow input and toggle the lights. Then do the same for the fast input leg. An analog voltmeter's needle will move if there is any voltage being applied while the light switch is toggled. (A digital voltmeter or DVM may not show the quick burst of voltage because the meter needs a little bit of time to measure the voltage.)

Another idea... disconnect the slow speed leg and see if the wipers still move when the light switch is toggled. Then try the same with the high speed leg. Should be able to get the problem isolated to a single leg this way.

Sure is a weird one!

[Mr.Fixit]

Check for continuity between the headlight circuit and the wiper circuit, at the fuse box with fuses removed. Also verify the ground connections as well. Get your head under the dash and look at the back of the switches themselves. They are close to one another. BLACK-FLAG ant, roach and gremlin spray

[G.R.]

Pete

Thanks I'll do as you suggest

[G.R.]

Fix-it

Black Flag

One thing I didn't mention is it doesn't happen every time the lights are turned on or switched hi-lo, then it will happen several times then stop, and it doesn't make a difference if the car is driven , started, or just ign. on.

[petek]

Betcha you've got an intermittent short somewhere. This could be a real bugger to find. Start with a visual inspection, following the wires from the wiper motor back to the wiper motor switch and then to the fuse. Look for things like push-on spade lugs sitting real close to each other (fuse box?) ... or maybe a couple of crimp-on wire taps setting next to each other.

[G.R.]

Thanks for your help guys.
Found a loose wiper ground wire and 2 loose spade lugs close to one another, one from the headlight circuit, the other the wiper power lead at the fuse block
So far it hasn't reocurred.
What is really bad for me is I can't drive the car, because I can't get into it because of my knee surgery--my knee doesn't bend too well yet--tried sitting in it on the passenger side this am got in barely but had to roll out of it onto to the floor to get out--if the pipes had been hot Wife is really enjoying this 'cuz she can drive it and the weather up here has finally turned nice.