C3 Tech/Performance V8 Technical Info, Internal Engine, External Engine, Basic Tech and Maintenance for the C3 Corvette
Sponsored by:
Sponsored by:

!978 With Wiper Electrical Issues

Thread Tools
 
Search this Thread
 
Old 10-13-2018, 01:04 AM
  #1  
dant849
Advanced
Thread Starter
 
dant849's Avatar
 
Member Since: Mar 2017
Location: Opelika Alabama
Posts: 73
Received 1 Like on 1 Post
Default !978 With Wiper Electrical Issues

Hello all....the wipers on my 78 stopped working. I checked the fuse which appeared to be intact (see pic) but I changed it anyway, Worked for a few minutes then stopped again. Checked the fuse again. Again, not obviously blown but check out the other pic. The end of the fuse is taking a bit of abuse as you can see. I unplugged the 2 connections at the motor, cleaned em up good, replaced the same fuse, worked like a charm. Shut her down and cranked up again a few minutes later, no wipers...what is the most efficient way to troubleshoot this? Thanks in advance,
Dan

Old 10-13-2018, 11:07 AM
  #2  
henrikse
Pro
 
henrikse's Avatar
 
Member Since: Nov 2016
Location: Kelowna British Columbia
Posts: 729
Received 115 Likes on 98 Posts
Default

Check the fuses with an ohmeter. Trust you have a multimeter. Sure looks like 2nd pic the fuse melted although at wrong spot. Usually they melt at the narrow spot in window as this is how they are designed. If you put the second one in while wiper motor was on with power you could do this maybe.
Anyway two thinks to check. First these fuse blocks can corrode where you install the fuse at each end. You can clean up each end where the fuse makes contact with a fiberglass pen or steel wool or fine emery. you can use spray contact cleaner. If it is good to start then use a meter on amp scale (30 amp) and see how much your wiper motor is drawing for current?
Old 10-13-2018, 12:59 PM
  #3  
0Willcox Corvette
Former Vendor
 
Willcox Corvette's Avatar
 
Member Since: Aug 2006
Location: Jeffersonville Indiana 812-288-7103
Posts: 76,656
Received 1,813 Likes on 1,458 Posts
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15

Default

I'd start by cleaning the fuse connectors in the fuse box.... then see what happens. It's common for the terminals in the fuse box to become corroded and when this happens it creates resistance. So clean them.. it's not easy but you can glue sand paper to a small dowel and rub it in and out of the terminal until cleaned.

If this doesn't fix the issue there is a ton of info on my tech page. The link is listed below.

Willcox

https://willcoxcorvette.com/
http://repairs.willcoxcorvette.com/
Old 10-14-2018, 03:16 AM
  #4  
dant849
Advanced
Thread Starter
 
dant849's Avatar
 
Member Since: Mar 2017
Location: Opelika Alabama
Posts: 73
Received 1 Like on 1 Post
Default

Originally Posted by henrikse
Check the fuses with an ohmeter. Trust you have a multimeter. Sure looks like 2nd pic the fuse melted although at wrong spot. Usually they melt at the narrow spot in window as this is how they are designed. If you put the second one in while wiper motor was on with power you could do this maybe.
Anyway two thinks to check. First these fuse blocks can corrode where you install the fuse at each end. You can clean up each end where the fuse makes contact with a fiberglass pen or steel wool or fine emery. you can use spray contact cleaner. If it is good to start then use a meter on amp scale (30 amp) and see how much your wiper motor is drawing for current?
thanks for your reply. I cleaned up the fuse block again and the wipers work so hopefully that was the biggest part of the problem. However, now instead of two speeds I only have one no matter what position I put the wiper switch in...
Old 10-14-2018, 03:18 AM
  #5  
dant849
Advanced
Thread Starter
 
dant849's Avatar
 
Member Since: Mar 2017
Location: Opelika Alabama
Posts: 73
Received 1 Like on 1 Post
Default

Originally Posted by henrikse
Check the fuses with an ohmeter. Trust you have a multimeter. Sure looks like 2nd pic the fuse melted although at wrong spot. Usually they melt at the narrow spot in window as this is how they are designed. If you put the second one in while wiper motor was on with power you could do this maybe.
Anyway two thinks to check. First these fuse blocks can corrode where you install the fuse at each end. You can clean up each end where the fuse makes contact with a fiberglass pen or steel wool or fine emery. you can use spray contact cleaner. If it is good to start then use a meter on amp scale (30 amp) and see how much your wiper motor is drawing for current?
Originally Posted by Willcox Corvette
I'd start by cleaning the fuse connectors in the fuse box.... then see what happens. It's common for the terminals in the fuse box to become corroded and when this happens it creates resistance. So clean them.. it's not easy but you can glue sand paper to a small dowel and rub it in and out of the terminal until cleaned.

If this doesn't fix the issue there is a ton of info on my tech page. The link is listed below.

Willcox

https://willcoxcorvette.com/
http://repairs.willcoxcorvette.com/
thank you very much.. Lots of good info on your links there. I appreciate it
Old 10-14-2018, 10:39 AM
  #6  
henrikse
Pro
 
henrikse's Avatar
 
Member Since: Nov 2016
Location: Kelowna British Columbia
Posts: 729
Received 115 Likes on 98 Posts
Default

Yes if only one speed use the Willcox website to bench test your wiper motor. These are old and the wiper switch is a terrible switch. Originals can be taken apart and cleaned up but rotten design. It can also be tested out of car. New ones from China intermittent too.
Old 10-14-2018, 11:01 AM
  #7  
0Willcox Corvette
Former Vendor
 
Willcox Corvette's Avatar
 
Member Since: Aug 2006
Location: Jeffersonville Indiana 812-288-7103
Posts: 76,656
Received 1,813 Likes on 1,458 Posts
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15

Default

Originally Posted by henrikse
Yes if only one speed use the Willcox website to bench test your wiper motor. These are old and the wiper switch is a terrible switch. Originals can be taken apart and cleaned up but rotten design. It can also be tested out of car. New ones from China intermittent too.


The imported switches are hit or miss with about 1 out of 10 being junk.

Here is how to rebuild the switch: http://repairs.willcoxcorvette.com/w...tch-repair.pdf

Here is how to test the switch once you get it out of the car.



If the car is in my shop I'll just rebuild the switch vs, selling a new one. And while it's hard to get the pot open, if you do decide to pull it apart just pay attention to how it came apart and don't drop the spring inside.



Willcox

https://willcoxcorvette.com/
http://repairs.willcoxcorvette.com/

Please bump our sale threads if you get a chance..

Get notified of new replies

To !978 With Wiper Electrical Issues




Quick Reply: !978 With Wiper Electrical Issues



All times are GMT -4. The time now is 05:48 PM.