Hey Buick-mates! Can anyone advise where to find out what's wrong? The problem is as follows: When I put the wipers on then all the instrument panel lights up (two green flashing lights and one red long light bulbs).And at the same time the gas meter drops to zero. However,the turn signals and the high beam will not turn on at that time (both do work normally if used). Then when I turn the wipers off they stay swinging about 1 inch from the bottom of the glass and don’t stop working until I turn off the power. Electrical matters are really hard for me (no experience) ... I tried to spray contact enhancing spray but no effect. I unplugged the power cord from the wipers and put it back, but it didn't help. I suspect something grounding is wrong(?) Still wondering how that gas meter "sinks" to the bottom when the wipers are used ... Could someone help me where to go to get the bug? Thanks in advance!(+sorry my english...).
You have a bad ground somewhere and the voltage is going to fround through unorthodox pathways instead of the intended pathway. Make sure you have the metal ground strap that is captured under one of the mounting bolts in tact and make sure the wiper switch is tight in the dash and providing a good ground. Tom Mooney
Doesn't one of the screws that secure the wiper motor go through a ground strap, on or near one of the rubber bushings? It's been about 30 years since I had a similar problem. Seems like an insufficient ground to me also.
Yep, Ground issue. Current is flowing through accessories (lights) in the path and using their ground path, instead of the intended ground for the accessory (wiper motor).
The way the wiper switch works is that there is NO electrical power to the wiper switch. It ALL operates via a ground at the switch tself. Tom T.
The black and blue wires are from the motor and water pump, and are grounded via the switch as Tom (teleriv) stated, completing the circuit. (most all items are always powered and activated by switch completing grounds) The Motor and Pump are powered by the yellow wire, and that is traced back to the fuse block. The other side of that fuse is connected to a pink wire that feeds to the ignition switch and also to the instrument panel circuit board. Lights, fuel gauge, The light green wire is tied to the instrument panel circuit board for the high beam light (long red light) and the light blue wire to the two green turn signal indicators. If the wiper switch is not grounding correctly, that can prevent the wiper motor from parking when the switch is turned off, the motor grounds to park (de-energizing), after completing the revolution once the switch is turned off opening the circuit). If the switch is bad the motor is still powered and maybe grounded via the current flow to ground. Buikula, do you have the shop manual? To verify the wiring? If not, can someone post the 65 Wildcat wiring?
There are two critical grounding paths in this system. The first ground is the metal strap I mentioned in my first post which is captured under one of the wiper motor mounting bolts and provides a ground for the internal relay/latch inside the wiper motor itself. The relay latches and unlatches the rotating assembly inside the motor to allow the motor to either run or return to a parked position. The second ground is the wiper switch which serves as the ground for the wiper motor itself. There is another consideration and that is the fact Buick issued several service bulletins to address various wiper issues and ultimately decided to offer a revised internal relay/latch assembly to solve the problems. Buikula, I should have a bench tested wiper motor on the shelf if you would like to purchase a replacement motor but I hesitate to sell the motors because often the issue is grounding and is external to the motor itself....or I can supply copies of the service bulletins for you if that will help. Good luck! Tom Mooney
I would think the fault is not very big (and that ground is the reason). I probably won't go until the weekend garage,i try then look every wirings. I have a Buick service manual,but as I said earlier electricity is not my "bisnes" . I'll put a message here when the fault clears up.
Hello everybody again for a after long time! The problem was still not solved...Today I was with a friend in garage (he understands more about electronics). First of all,it looks like the wiper switch (probably from the factory) has been replaced in the car. The manual talks about a 3-port,but this is a 4-port (sorry I didn't take a picture).One is the ground wire,so wiper switch not need "ground he self" this anymore (like what peoples speak before this page). We measured all ground wires and all connections etc. were cleaned (also they were all visually good/clean already+we put contact spray placed). In addition to these, the surface wires were placed on the ground of the motor as well as on the wiper switch. But nothing... the same effect still continues!!! My friend thinks the reason is to be the motor relay. Could anyone say if this could be the fault? And would anyone have any tips on where to order a new one?
I am a retired Electronics Technician, so I can give you an opinion, but without actually seeing the car, it is just advice. Your friend is correct, it could definitely be the motor relay. I am also suspicious of the replacement switch. I would try replacing the switch first, as it is the most inexpensive part. There could be some internal wiring on the new switch that isn't compatible with you car. If you ask, maybe someone on the board would have one you could try, or buy. If this doesn't provide you with a solution, then try the motor. Once again, you may be able to get one through the board. I have a '66 Wildcat, and Tom Tesco (telriv) has provided me with numerous parts and is a great person to deal with. I hope this works for you. As I said, it is hard to diagnose problems remotely. Have a wonderful rest of your weekend, everyone! Chuck
