Hey everyone,

Proud new owner of an '84 C4. Having some electrical issues, but right now, just focusing on the wipers. They don't come on. Not sure if it's the wiper motor, the motor cover, the wiper control switch or something else. I've not begun troubleshooting in earnest yet, because I'm waiting on my FSM too. But I checked the fuse and the fuse is OK. Have a light-up volt tester on the way.

Anyway, I found this video online where it discusses what is more-likely the cause of failure: the motor cover.

Can anybody lead me through the correct troubleshooting, or at least a prior thread here that details it?

Added for consideration; I have no power to my door locks, cigarette lighter, interior door lights and engine hood lamps as well. Wondering how much of that is related .....

Thanks in advance.
Chris

 

With no tools or manual. There's not much to do but wait. DVOM should be put on your things to get list. Bump the thread when your stuff comes.

 

DVOM? What's that stand for?

In the mean time, I have the factory service manuals ordered (with the electrical supplement) and a 12v test lamp on the way to go with my multimeter.

 

Hello there Chris,

Digital Volt Ohm Meter, an extremely important tool on an Electronic Fuel Injected engine. Battery connections are very important to keep clean in order to avoid troubles. I have spent a lot of time cleaning connections on my 1988 C4. I had a almost 2 volt drop in the electrical system with a huge chunk of corrosion/resistance. Start at your battery and go from there till you find the device keeping "it" from getting power. My issues were where the Fusible links got their Power on my C4.

The most important is the Factory Service Manuals and you have that covered, smart move.
A Fuel Pressure gauge is another must have in my opinion.

I am a user and a big fan of the "Power Probe" 4th generation electrical testing device. I have two of them and use them frequently. A great tool for fiberglass cars I am now at the Scanner phase of C4's where I get to see what little data was collected back in the old days.

The shop manual should be able to help you fix the electrical stuff. They have troubleshooting charts that are wonderful.

I hope you get lots of fun out of your "new to you" Corvette!

Best regards,
Chris

 

Thanks for the additional explanation. Would my digital multimeter be considered a DVOM. I can measure ohms and voltage. Or is a DVOM a whole different gadget I should purchase?

 

If you have power at the wiper motor try tapping it with the wood end of a hammer. Don't tap real hard to break it. I had read several years ago that sometimes from sitting by tapping on the motor assembly jars it enough to start working. This worked for one of my cars in the past when the wipers did not work. I no longer have the link to the article. It may have been from this forum.

Good luck and enjoy your new project.

 

I know I've got an old wooden Yankees fan appreciation day bat somewhere ......

 

Same, same. That's why it's called a digital multi-meter. Very versatile. My DMM/DVM/DVOM also has buzzer for easily checking continuity, and can measure the beta (hFE) of both NPN and PNP transistors, if you might be curious about that! And mine's not even an expensive meter, like some who post here.

 

Yes your meter is sometimes referred to as a DVOM in some industries and a multi meter in others. If you can measure DC and AC volts and ohms then you can fault find on your car.

 

sorry Roy I answered the same question before getting to the end of the thread. I have a Fluke 87 because I worked in control systems for years in the electricity industry; but I bought my dad a cheap fluke copy with the transistor test ports and it worked great. The old mans gone now but I left the meter at my mums house so I can deal with any surprise issues she has when I visit.

 

Updating this thread: both the wiper motor and washer motor needed to be replaced. All is well and good now.

 

Replace the courtesy fuse or double check it with the multimeter. Fuses can look good but still be bad.

 

Glad you found your solution, and I thought I'd add a few observations for anyone who finds this later in researching their own similar problem. I have the same symptoms and I found that moving the electrical connector caused eveyrthing to work again. These plastic connectors deform and get brittle as they age, especially underhood where temperatures are high. I'll see if this provides a lasting solution, and if it doesn't I'll be doing as you have done.