69 windshield wipers troubleshooting help !
Thread Starter
Cruising
Joined: Apr 2025
Posts: 13
Likes: 0
69 windshield wipers troubleshooting help !
Hi everyone, just signed up here 🙂.. to start l have some skills on this stuff l need some advise however, to start my 69 wipers were fine and just stopped working. I got the wipers to work again but the door would not pop l had to gently lift it. I took the guage cluster out so l could test the connector for the vacuum solenoid it’s tested no power with the switch on low ..and no power off as well, here is the funny part now l have no power at the fuse… after l disconnected the solenoid, Whatever is the matter its electric and not a hard problem l don’t think l just have to find it .. also seems on vettes there is some negative 12 volt stuff going on .. help a feller please ..🙂🙂thank you ..
Thread Starter
Cruising
Joined: Apr 2025
Posts: 13
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I have a haynes manual with the wiring diagram, there has to be a better wiring diagram. I have spent a fair bit of time online looking for a better one and they are waste of time being largely mislabelled..thanks guys.
Thread Starter
Cruising
Joined: Apr 2025
Posts: 13
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No sir .. which l thought was funny it worked just fine before .. thank you for responding .. l am going over the wiring diagram l have to try and figure this thing out .. looks as though power comes from the starter solenoid .
Melting Slicks
Joined: Nov 2006
Posts: 3,409
Likes: 1,821
From: Apple Valley, MN
Melting Slicks
Joined: Feb 2018
Posts: 2,326
Likes: 721
From: Marietta GA
The wiper door is operated by vacuum generated by the engine (also used for headlight doors and hvac ducts). Search Google for a vacuum diagram and then start doing some detective work. If the rubber hoses are original to the car, it probably makes more sense to change them out. The hose sets are readily available and have color stripes to assist you as to where they go. There is also an electrical switch (wiper door) tat allows the wiper motor to be energized, but only ONCE the door has opened, sorta complicated.
Thread Starter
Cruising
Joined: Apr 2025
Posts: 13
Likes: 0
I am pretty certain this is not vacuum related, the switch the gets made when the door opens is good .. and the door functioned perfectly then the wipers stopped .. but the door opened .. then l lost power to the fuse panel and lights out .. l am sure the wipers will work once l find whatever the problem is .. also l think if there were a vacuum leak of any size decent size my engine would probably idle fast .. and it doesn’t.. hmm.. pretty sure the vacuum module need the tach is fine as well .. l gotta sort out why l don’t have power all of a sudden .. gotta go back to the starter solenoid to cotinue .. oh the car starts runs fine everything works but the wipers ..
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Melting Slicks
Joined: Feb 2018
Posts: 2,326
Likes: 721
From: Marietta GA
I reread your post and it seems that you may have some electrical issues along with the vacuum problems. First you really need a wiring schematic for your YEAR car. You may find a used Chevrolet Service Manual on eBay at a reasonable price. Look at the Bakelite connector on the firewall that goes to the fuse box. Good Luck, being a detective is one of the skills you need, when you own a C3.
Thread Starter
Cruising
Joined: Apr 2025
Posts: 13
Likes: 0
Been here many times, l have seven hot rods .. this is a bit different and like everyone sometimes l need a bit of advise .. 🙂🙂✌️if anyone else has any ideas l am listening .. 🤗 oh and l will check the bulkhead..
Burning Brakes
Joined: Sep 2020
Posts: 827
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From: Chapin SC 29036
I have posted a 1969 wiring diagram that you can download. I am working on an update to it, but it mostly clean-up to try and make a complicated diagram a little easier to view.
If you are on the C3 area, try doing a search on "update 1969 diagram" and it should find a thread dated Feb 19, 2025, with the title "Update of 1969 wiring diagram in color". There are two PDF versions of it, one is the entire diagram for use on a PC and the other version "pages" is broken down into pages so that it can be easily printed and then fastened together.
If you are on the C3 area, try doing a search on "update 1969 diagram" and it should find a thread dated Feb 19, 2025, with the title "Update of 1969 wiring diagram in color". There are two PDF versions of it, one is the entire diagram for use on a PC and the other version "pages" is broken down into pages so that it can be easily printed and then fastened together.
Burning Brakes
Joined: Sep 2020
Posts: 827
Likes: 807
From: Chapin SC 29036
The Wiper fuse receives its power from the Ignition Switch. It supplies power to the Wiper, Radio and Heater fuses via a Brown wire, unless you have A/C in which case there is an Orange wire to the Heater fuse and the Brown wire only goes to the other two fuses. The connection also goes to the Bulkhead connector location DU or UD as a 12gauge wire. It comes out on the engine side as a 20-gauge Brown/White wire to the Alternator. Being 20 gauge, it is a feeder, not the supply voltage.
Thread Starter
Cruising
Joined: Apr 2025
Posts: 13
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Radio works but it two shows no power its the fuse right above the windshield wiper ..this is a late 69. I was testing the fuse panel with a wire attached directly to the negative terminal of the battery, if I ground that wire it shows 12 volts, that doesnt seem normal to me, however except the wipers zero problems everything works.
Burning Brakes
Joined: Sep 2020
Posts: 827
Likes: 807
From: Chapin SC 29036
Sometimes a 12v test lamp can be easier to use than a meter. If the lamp lights, you have some voltage. It might not be 12v, but there is something there. Corvettes are a unique animal in the fact that the body is fiberglass, so every circuit needs a ground run to it. Sometimes the ground is run from panel to panel, so when something doesn't work tracking down the missing ground can get confusing. In most cars the entire body is ground and everything else only needs one wire to operate. The wiper switch on the center console gets its ground from the metal bezel that all of the gauges are attached to and there should be a ground wire attached to the bezel. Not the way I would have designed it, but they didn't ask me.
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,135
Likes: 4,244
From: US-PNW
I'm a little confused by some of your replies -- they're kinda running information and responses together.
The door should be able to be activated independently of the wipers - as well as in conjunction with them. The wiper switch won't work at all unless the door is fully open and telling the switch it's open.
First make sure the door opens and closes properly by using the over-ride pull-down valve under the steering column (engine must be running). Without that happening, working on the electrical switching may be fruitless steps in the wrong direction.
If the door fully opens by the over-ride, next check that the "yes, I'm open" switch is being activated. This in the engine compartment, upper left-center of the firewall as you are standing there looking at the engine.
The door should be able to be activated independently of the wipers - as well as in conjunction with them. The wiper switch won't work at all unless the door is fully open and telling the switch it's open.
First make sure the door opens and closes properly by using the over-ride pull-down valve under the steering column (engine must be running). Without that happening, working on the electrical switching may be fruitless steps in the wrong direction.
If the door fully opens by the over-ride, next check that the "yes, I'm open" switch is being activated. This in the engine compartment, upper left-center of the firewall as you are standing there looking at the engine.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
Door opens via VACUUM. Wipers (electric) won't work until door is fully open. The "wiper parking switch" (under RH wiper) and the solenoid vacuum switch (mounted to rear of tachometer housing) must function properly for door to open [along with other things].P.S. The only useful manuals for these cars is the Chevrolet Service Manual and the Chevrolet Overhaul Manual. All others are a very poor substitute and have minimal useful information. The AIM is a Chevrolet assembly line aid that is invaluable when working on your car. You must have one if you are a DIY'er.