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Wipers shouldn't come on until the door opens. There's an interlock switch on the firewall, top center, which prevents the wiper motor from being powered on until the door opens, pushing in the plunger. Sounds like somebody bypassed this switch?
If the door isn't opening, could be one of several problems. If the overide works, check the solenoid mounted to the rear of the tach, make sure it's plugged in, hoses connected. This solenoid controls open/close when the override is not being used.
Hi D,
Here's the switch on the firewall that BB described.
If it's working properly it should prevent the wipers from starting till the door is open
The plunger should only depress the button on the switch when the door is fully OPEN.
It's at that point that the switch completes the circuit to the wiper motor and the wipers begin to sweep.
Check it out.
When the door is CLOSED the plunger should be pulled back from button.
What do you see?
Regards,
Alan
Hmmm, looks like you are a new owner! Congratulations! It would be my guess your new toy has had a visit from our friend Bubba. It is fairly common for previous owners to be somewhat creative in the ways they would try to correct an inoperative wiper door. My suggestions to you would be to study a correct vacuum hose schematic to make sure all the individual components are in place and plumbed correctly. Until you do this it would be somewhat akin to throwing darts to diagnose the issue(s).
Grmbl... The switch is there but I can already tell the wiring has been Bubbafied... My guess is the solenoid behind the tach. Rather than fix that, Bubba bypassed.
I need to replace the wiper switch which is acting weird.
Thanks gents. And to be clear... it seems that the switch that prevents the wipers from coming into action until the wiper door opens has been disabled.
When I throw the wiper switch above the gauge cluster, the wiper door doesn’t even begin to open. The wipers just crash into it.
Bubba rigged it as using th overide switch first then the wiper switch.
So, I need to pull off my tach/speedo gauge panel/front to get to the solenoid?
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
Here's a couple of photos of the wiper door safety switch. One showing the plunger down (wipers parked) and one showing the plunger up (wipers sweeping).
The opening of the door controls the the electrical switch on the firewall....only when the door is fully open does the door mechanism push the button on the switch allowing the wiper motor to start.
The 'plunger' on the vacuum switch is controlled by the 'lever' on the wiper arm transmission.
It's only when the wiper MOTOR cycles to it's PARK position the lever pushes the plunger down and that the door can close.
So the firewall switch prevents the wiper arms from hitting the door when the dash switch is turned on and the wiper bay vacuum switch prevents the door from from closing until the wipers are in the park position.
There is adjustment for fine tuning the 'timing' on each of these functions.
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If you have to buy a new wiper switch someday, either get a used original or look at Willcox for one that he checks before selling. There was/is a bunch of chinese garbage out there and I had one. They will fail immediately.
Oh ya, welcome aboard. If you can pass the initiation of getting the wiper system working, then you pass and are officially a C3 Member. It is the single most frustrating thing next to pulling your dash then trying to reinstall in. So pulling the seat and wheel is the easiest way to deal with anything under the dash. If you do pull it, replace all your bulbs and anything else back there so you don't have to go int there too often.
EDITED TO ADD
I forgot about bleeding the brakes to get out stubborn trapped air pockets in the system. Look at investing in a power bleeder. It will help with a lot frustration. Of course search these subjects before tackling to learn from others experiences
Post pics of your ride for us!!!
Last edited by Rescue Rogers; Dec 3, 2017 at 08:45 AM.
So, I need to pull off my tach/speedo gauge panel/front to get to the solenoid?
In a word, no. All tests needed to evaluate the solenoid on the back of the tach can be done without removing even one screw from the dash. If you have access to a Mityvac or equivalent vacuum pump I can walk you through the process. The electrical test just requires a common voltmeter.
Thanks gents. Really fantastic feedback here. Well, the weekend has come to an end, I expect that I’ll have to continue the diagnosis next weekend. Hopefully it is only a matter of adjusting and tweaking.
Hi D,
I agree with Dave that having a small vacuum pump with a gauge, like a Mity-Vac, allows you to test the operation of all the vacuum components of the system individually .
If you don't have one it might be wise to spring for the cost of one.
It helps make the vacuum system for the wipers and headlights a little less of a mystery.
Good Luck!
Regards,
Alan
Well, I removed the wiper arms to test without them -this to avoid them crashing into the door and each other as I figure out what is going on. I discovered that when throwing the wiper switch on the dash, the door does not open at all. It’s not that the wipers crash into it before it can open and the door gets stuck; it just never even tries. Bubba had relied on the overide. The wiper door switch that prevents the wipers from operating until the door is fully open is also not working. I’ll need to figure out why.
Also, I had noticed that one of the wiper arms was a bit “floppy”. I found out why. Not sure that these studs are readily available.
Hi D,
The photos aren't very encouraging.
I think you're going to have to find a used right-side wiper transmission... it'll have the long arm that connects to the wiper motor at the center of the wiper bay and a the key that fits in the slot in the wiper arm.
I also think you MAY need a used but good right-side wiper arm. You won't know for sure until you have a good transmission to attach the the current arm to.
Regards,
Alan
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.
In the meantime, using a DMM, how does one check the behind-tach-solenoid?
Really quite simple to do. The electrical connection is not polarized, so you can hook up a voltmeter to the either side of the leads from the solenoid harness to test the 12 volt signal when the wiper switch is activated. If you can verify the solenoid is getting 12 volts or thereabouts, reconnect the harness and activate the switch. You should be listening for a faint but audible click coming from the solenoid when you trip the wiper switch. I often just use a 9 volt transistor battery and touch the contacts together. If the solenoid is good, you will hear a click coming from it.
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.
Test the 12 operation of the solenoid and check back.
Just so you know, Dave is the resident expert here on wiper/headlight systems and vacuum parts. He can rebuild some of your original vacuum parts to work like new unlike buying some of the new garbage out there like vacuum relays and wiper safety switches that are not up to standard.
Just so you know, Dave is the resident expert here on wiper/headlight systems and vacuum parts. He can rebuild some of your original vacuum parts to work like new unlike buying some of the new garbage out there like vacuum relays and wiper safety switches that are not up to standard.
Yup, utter crap.
If your solenoid is bad either electrically or vacuum you can rebuild it yourself if the coil is still good. Basically you take it apart and clean it up. That usually does the trick. I did years ago before they were available in the aftermarket. It's an easy job once you get the solenoid out and you don't have to deal with the Chinese crap parts.
Wiper/wiper door interference
out there and I had one. They will fail immediately.
If you can pass the initiation of getting the wiper system working, then you pass and are officially a C3 Member. It is the single most frustrating thing next to pulling your dash then trying to reinstall in. So pulling the seat and wheel is the easiest way to deal with anything under the dash. If you do pull it, replace all your bulbs and anything else back there so you don't have to go int there too often.
Just so you know, Dave is the resident expert here on wiper/headlight systems and vacuum parts. He can rebuild some of your original vacuum parts to work like new unlike buying some of the new garbage out there like vacuum relays and wiper safety switches that are not up to standard.