Bench test for Windshield wiper switch

[Bill E.]

My '74 wipers work when the washer is pushed but not when the slow or fast setting is activated. I've removed the switch and panel and need to know how to bench test the switch. Anything else I should check, any help would be greatly appreceated. Thanks, Bill

[David T.]

Re: Bench test for Windshield wiper switch

Hi Bill,

I looked in my 74 Factory Service Manual, but it was no help with the wiper circuit. Does it continue to operate at low speed after the washer finishes cycling? If so I would suspect the switch. I would use an ohmmeter to check for continuity at the contacts with the lever in different positions. You should see changes in continuity as the switch is moved through its positions. I realize this isn't much help but I can't seem to find the appropriate information on the switch terminal configuration. However, I believe the wiper switches are the same from 1968-1976. If you can find a fellow C3 Vette owner with a known good switch who will let you substitute it, you would have a definitive test of your wiper switch circuit. Good luck!

[Gary C.]

Re: Bench test for Windshield wiper switch

Bill, give fellow NCRS member Tom Maxwell a call (301) 948-9481 Tom rebuilds wiper motors, etc. Capital Auto Restorations. Tom can tell you how to check the switch. As previous poster said check switch position continuity with an ohm meter. One lead on the battery side and move the other lead to the low, high switch outputs and see if there's continuity between or shows open. Gary....

[Paul O.]

Re: Bench test for Windshield wiper switch

I always try to remember that a corvette is different then most other cars. That in most cars the item your turning on is looking for power (voltage/amperage) and in corvettes is looking for ground see if the washer gives a ground thru a different wire/contact and the normal contacts is another for wipers. Hope that helps. Paul

[Bill E.]

Re: Bench test for Windshield wiper switch

Thanks for the replies. I called Tom, nice guy, but he doesn't work on C-3's. I cleaned all the connections on switch and motor and now it works but the washer keeps pumping whenever the wipers are tuned on. I ordered a switch from Mid-America today. Either this will fix the problem or eliminate the switch as the guilty party. Bill

[Richard R.]

Re: Bench test for Windshield wiper switch

Bill
did the new switch solve the problem or was their another problem?

[Bill E.]

Re: Bench test for Windshield wiper switch

It was the switch. Everything works OK.