relay chatters like &^$* when the switch is operated so I made a bypass like this one:
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but now there's zippo from it.

the wiper motor had actually operated on both speeds intermittently, and relay tripped for the washer setting too. Any ideas?

 

Yeah...I have a great idea. Put it back like it was originally. The chattering is only a momentary issue. When the wiper switch is in its location for operation...the relay stops chattering. I have experienced it on almost every Corvette with this style of switch and control assembly. The circuitry is much different than the earlier Corvettes in regards to this switch and control. The motor is still basically the same in how it goes into park, low and high speeds....basically moving the ground signal on the outer two terminals of your 3 wire connector on the wiper motor...so if you are trying to re-engineer it...good luck. You have to get the ground circuit to change correctly to make it work. If GM is switching 12 volt power in the switch to activate the relay to activate a ground......it will require some serious testing to get it to bypass the relay control. I have not looked into the system to actually chart the circuits to by-pass this relay "chattering" issue....only because I see no need. I prefer to leave it alone and still allow the intermittent option to function.

You need to get a wiring diagram if you do not have one and draw out the circuits for the wiper system and understand what is going on when you test these wires during different functions of the switch.

DUB

 

DUB - your opinion is that this is a switch problem, not a relay problem? The most I was trying to accomplish was to eliminate/isolate the problem component, never intended to eliminate the intermittent function. Could the switch's ground be faulty?

 

I got pretty much the same problem on my '78. When I touch the wiper switch, the relay starts clicking like a telegraph operator on crack. Seems to quit while wipers are working, then when I turn them off, they won't park. They twitch like they want to park, but can't stop until I can shut the engine off and restart. I'm just gonna sit back and listen on this one.

 

Sorry that I misunderstood why you did what you did.

I have encountered on so many Corvettes that the switch has age on it...thus it is "loose" so-to-speak. It will work...but it is "touchy" and can often times take a precise touch to get it to the "spot" needed to get it to work without any chattering.

I really hate to write it...but I honestly would have to have the car in my shop so diagnostics could be performed and find the issue. I do not know if I would advise buying a new wiper switch..because I am not "feeling" the detents in the switch when it is slid up or down. I know that new switches (or at least factory originals back in the day) had definite detent spots that you could feel. The same similar issue occurs on the earlier 68-76 Corvettes with the wiper switch in the top of the dash. Those do not chatter (due to not having the relays set-up for intermittent wipers)...but they still can get really loose and touchy to get the wiper motor to work.

SO knowing that the control signals for the relay come from the switch...that is where I would start...then i would find the circuit that is causing the relay to chatter and see if it has anything to do with the wiper switch...or if it is a component in the relay circuit board and have it repaired.

Finding the issue can be rather time consuming...and I have spent numerous hours fixing electrical issues on Corvettes just so I know what caused the problem....and that time was chalked up to learning experience.

Not knowing if you have a good friend with a Corvette like yours that has that relay assembly...switch it with yours and see if it is still chattering. Because if his/her Corvette does not chatter when the wipers are activated...you can deduce that if you swapped it out and it goes away...it would have nothing to do with the switch...and vice-versa....if you swapped out the switch and kept your relay attached.

DUB

 

DUB - thanks, no harm no foul. it obvious that you're a dedicated tech and thanks for the very good advise. since the relay by pass ended up giving me zip, i'll reinstall it and i'll go to the other end and do the same with the switch, fyi the detents are very definate, no slop, jump the terminals and i'm guessing the motor will light up just fine, if not i'll dig into the schematics. - stu ps - took the vette out with the club yesterday for the first time and blew the hell out of some desert roads . . . much fun!
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