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Hi D,
Testing the solenoid valve.
It has both an electrical and vacuum function.
Yellow port is near the electrical connections.
Blue port is near the filter end of the switch.
With the solenoid NOT energized....
Connect the pump to the BLUE port and block the YELLOW port. The vacuum should be maintained.
With the solenoid energized....
Connect the pump to the yellow port. The vacuum should be maintained.
I ordered a mityvac online; which should get here in time for the weekend. Clearly I will need one of those to diagnose, troubleshoot and maintain this car.
I am glad to read that the behind-tach solenoid can be rebuilt... and can be tested while in the car.
I believe I can energize the solenoid by applying 12V (or 9V transistor batt (thanks for tip)) ti the brown wire coming from the wiper motor.
I'll keep you posted on how the test goes. While I find a driver's side transmission and wiper arm, I will probably drill a couple of holes in the wiper arm and tap in some set screws. Only temporary. In the meantime I need to figure out what all needs to be replaced (if anything). I want to make this one order for parts to fix this and not find out that yet another valve has failed.
Hey Dorian.
I like your '69.
Do you know what color Blue that is?
I'm still trying to confirm my non-'69 Blue color code.
Thought it was '70s Bridgehampton, but not quite.
I know for sure, it's not correct '69 LeMans.
Fix the safety switch first to see if the door will open on it's own because if the wipers are hitting the door before it opens they may be holding the door closed.
The door solenoid is at the bottom of the tach. The only reason it's hard to get to is the size of the under dash area. It helps to take the drivers seat and the steering wheel off to give you more room.
While you are at it you might as well check the vacuum safety switch too. This keeps the wiper door from closing on the wipers before they are fully parked. It's located under the grill in front of the wiper door on the passenger side.
I'd post pictures of the solenoid but Alan always has better ones and I'm sure he'll post them up.
The two safety switches. One electrical one vacuum
This VACUUM safety switch is what I replaced when I fixed the signal for wiper door when I had my '69 L46. I ensured the electrical switch with the contact was properly adjusted. Then, I had to replace the bushings on the arms that rotate the wiper door open as it was too loose and not fully lifting before wipers came on. Once it was sorted out, it performed smoothly. Only challenge is when there is ice formed over the wiper door/hood edge. Then, you need to (carefully) remove the ice. Otherwise, the wiper door may jam or get damaged trying to open.
Out of interest. Assuming the solenoid needs a good cleaning... I take it the only way to get the solenoid out is by disassembling the front of the dash ?
I have had very good luck getting the solenoid out from underneath the dash. It really helps to remove the drivers seat and lay something more comfortable for you to lay on your back on. Use an inspection mirror before you begin so you will know where to look for it. I use a small socket to break the screws loose and finish with a flex drive.
To reinstall, make a small piece (1/4" sq.) of card stock paper, push a toothpick through the middle to make a hole, and put it behind the flange of the solenoid where the screw goes through it. Tighten the screw up and it will hold the screw in place till you can get it back in the back of the tach. Then tighten with a socket.
If I were you, a thorough testing of the solenoid in the car and the control circuit vacuum should be first. Solenoids don't fail that often.
Note; all bets are off if you have air conditioning. I haven't had to do one, been lucky I guess. The plenums under the dash make it much more difficult.
I have had very good luck getting the solenoid out from underneath the dash. It really helps to remove the drivers seat and lay something more comfortable for you to lay on your back on. Use an inspection mirror before you begin so you will know where to look for it. I use a small socket to break the screws loose and finish with a flex drive.
To reinstall, make a small piece (1/4" sq.) of card stock paper, push a toothpick through the middle to make a hole, and put it behind the flange of the solenoid where the screw goes through it. Tighten the screw up and it will hold the screw in place till you can get it back in the back of the tach. Then tighten with a socket.
If I were you, a thorough testing of the solenoid in the car and the control circuit vacuum should be first. Solenoids don't fail that often.
Note; all bets are off if you have air conditioning. I haven't had to do one, been lucky I guess. The plenums under the dash make it much more difficult.
If I work under the driver dash I also take the steering wheel off along with taking out the seat. Makes it more comfortable.
Well, I checked the solenoid at the back of the tach. Success!!! It gives a crisp click when 12v are applied.
So, it has to be the yellow or light blue wires. Two of each.
If that is the same yellow wire that runs the wiper motor and wager, it has 12v on IGN; I tapped my carb choke off of it. Will verify. Things are beginning to point to a ground issue. Might be hard to see but those are two alligator clips on the solenoid. Hmmm, I should check the vacuum flow nonetheless.
Good. Chances are the vacuum hoses are correct under the dash as everything in your picture looks good and Bubba is usually over 300lbs and can't get under there to screw anything up.
I'd concentrate on your electrical safety switch first just so you can keep your wipers from crashing then move on to the vacuum side and get the door working properly.
Getting the wiper door working is probably one of the most satisfying results you can have on our cars.
Edit - Search the treads for wiring diagrams. Also if you don't have the AIM for your car I suggest to get one. It will have the wiring diagram in it. All you have to do is make copies of each page and align them together and it makes a nice big wiring diagram. The legend on the bottom of each page shows where they go.
My '71 wiring shows Light Blue and Yellow going to the solenoid.
Last edited by theandies; Dec 9, 2017 at 10:12 AM.
Do you know there is a wiper motor override switch? It is located between the headlight and the wiper door override switches. The ***** are often missing. If you turn the switch you can disable the wiper motor to make your diagnosing a lot easier.
Another mistake some make is when they plug in the connector to the switch above the center gauges. The connector is "keyed" but it's easy to plug it in backwards and that causes a lot of strange problems. You'll see on the connector a tab on one side of it. On the bezel you'll see a piece of metal sticking out. The tab on the connector should be opposite this metal tang. The tang and tab is there to keep the connector from being plugged in backwards. When you check it (and you should check it) you'll see how easy it would be to connect it backwards.
