Hello Everyone,

I recently picked up a '77 Oldsmobile Cutlass Supreme for a decent deal from a family member. The car starts and runs great, is outfitted with the Olds 350, and doesn't appear to have any glaringly obvious leaks throughout. Unfortunately, while on the 20 mile trip back to my home after the purchase, it began to rain and I discovered that the windshield wipers don't appear to work anymore. They are two speed, (Low and High) and I was wondering where I should begin to troubleshoot this issue. I assume there is a fuse for the wipers, does anyone have the location of that fuse to check? If the fuse ends up appearing to look okay, how would one recommend troubleshooting whether or not the motor is bad, or the switch itself is faulty? I appreciate any responses, as I'd love to be able to take this beaut out regardless of the weather!

Thank you

 

You need a chassis service manual. You can view at wildaboutcars.com and download sections. free to join.

 

And, to clarify, the two-speed, depressed-park wipers should be the same from the mid-sixties through your year, at least, so even though there's no '77 manual, all the information is there.
The wiper motor troubleshooting is in the electrical section in the earlier years, up to '68 or '69, and is in the Fisher Body Manual after that.

Your fuse block should be just above your left foot.
One fuse should say "Wipers."

- Eric

 

when you lack the troubleshooting diagram from the manual, the first blind shot in the dark after checking the fuse is to check ground. 2 alligator clips on a length of wire work. Clip one to the bare metal of the housing, the other end to a body ground screw and hit the switch. If you noticed that the wipers were slower than you'd expect prior to failure, that's going to be a high percentage win. I'm 3 for 5 on that one.

 

Thanks, Eric, did not know that about the manuals.

 

Also, expanding upon Professur's advice, the wiper motor is rubber-mounted, but needs to be grounded in order to work.
There should be a small sheet metal tab that sits under one bolt and connects the motor to the firewall. If someone left it out or it got damaged, that'd keep it from working, too.

- Eric

 

Hello may I make a suggestion; I had the same problem and it turned out to be the wiper switch itself. what happen was; the unit had come apart inside the dash and separated from the body. Installed a new switch and problem solved. The way the unit is assembled is sort of a pressed fit and over time depressing the wash button makes the housing weak and the electrical part separate's from the housing; that is what I found hanging underneath the dash. All the small parts of the switch assembly falls out of the housing and if you can find all the small pieces it can be put back together again. Tried and true to this date.

 

Hello everyone,

Thank you for all the suggestions. I haven't had a chance to investigate the issue very throughly, I'm saving that for tonight. I just wanted to be able to hit the ground running, and I definitely have more to work with than I had prior to opening this thread. I'll take a look at what manuals I can dig up, thank you m371961. I'll check the status of the ground and the switch itself. The car had been sitting for a couple of years, so it's possible that either things have detached through vibrations, or damaged by rodents. Either way, thank you for the prompt responses, and I'll keep this thread updated with what I find out!

 

Hate to bring up a terribly old thread, but I did actually manage to get the wipers working in my '77 Cutlass again. The car itself has some electrical short somewhere that causes the front right speaker to cut out. For a time, the fix was to honk the horn, which would bring that speak back to life. After a while, that "fix" wore itself out, and I began moving the switch for the wipers to create the electrical change to get the speaker to come back. Eventually, one of the times I moved the switch for the wipers, they too came to life. I chalk it up to corrosion in the switch itself that finally wore away with the switch being used again. Now to conquer the electrical problem before that becomes more concerning..

 

 

This is one of the reasons why I consider the wiring harness to be a consumable. Insulation dries out, wires rub together, like a pair of 12 year olds together unsupervised, they can't be up to any good. Fortunately our older cars lack the 15 miles of wiring that new cars have and whipping together a new harness isn't all that complicated or expensive. If you're already looking at 3 compromised systems, a full rewire would be high on my suggestions list.

That said, the speaker working after honking the horn ....