1970 Wipers/Wiper Door Inoperative (KW=missile)

[Don]

This is what I'm faced with on a '70 convertible (early production): 1--Wiper door opens when you use the under-dash bypass. 2--Wiper door does not open when you move the windshield wiper switch to low or high speed. 3--The wipers do not operate when you move the windshield wiper switch to low or high speed. 4--The wipers do operate if you hold down the wiper switch (as though you were using the washer).

The following have been investigated/checked: VACUUM COMPONENTS: 1--Vacuum reserve tank. OK 2--Manual vacuum valve (under dash). OK 3--Interlock switch (vacuum) in right plenum. Have not checked. 4--Vacuum control solenoid (under tach behind dash). Have not checked. ELECTRICAL COMPONENTS: 1--Wiper switch on dash. OK for washer. Assuming it's OK for lo-hi speeds since previous owner says he replaced it (have not verified that). May be noteworthy that the motor clicks once when you slide the wiper switch to lo; when you switch to off and switch to lo again, there is no click. 2--Wiper door limit switch. OK 3--Rotary service switch (under dash). OK 4--External relay (in front of floor console). Have not checked. 5--Vacuum control solenoid (under tach behind dash). Have not checked. 6--Windshield wiper fuse. OK 7--Fuse link (at horn relay). OK 8--Wiper motor relay (integral). Have not checked (motor assembly has NOT been removed from the car).

While check-out is not complete, it appears that those not checked should be OK since the wipers work if you hold down the wiper-washer switch. Maybe that's an incorrect assumption.

One of the previous owners (several years ago) replaced the wiper motor with a used one. The previous owner said, during his ownership, the wipers NEVER did anything other than what they are doing now...which is what I'm trying to fix. I'm really suspecting the wiper motor itself with its integral relay. I'm pausing to ask for help before I spend large dollars on potentially needless pasrts like a new wiper motor. I would prefer to really zero-in on the troublesome part(s) before ordering anything.

If you can point me to where on the web I could find some answers or if you have some from your own experience, I would be very appreciative!!

Thanks to anyone who can help or advise!!!

Don

[Jack H.]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

Symptoms, if reported accurately, clearly point to vacuum control solenoid fault (back of tach). Could be as simple as wires not connected and/or vac lines to/from solenoid lack integrity. Shudder if the electro-mechanical relay is fried internally because, at last check, they're discontinued, not reproduced and prices float up into the $150 range for a good used and/or NOS replacement....

[Joe L.]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

Don-----

You mention that you have not checked the dash wiper switch. Well, the thing that I'd check for here is that the switch has a good ground. My recollection is that this switch operates by establishing a connection to ground for each of the positions. However, if the switch gounding is deficient, then it cannot function properly.

[bruce]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

Don to go hand in hand with what Joe says. Make sure the center instrument cluster, the switch is at the top of this panel, is not broken. What happens is when you try to remove this panel/cluster, unknowing(I'm not saying you) people don't undo the radio knob nuts and the bottom console nuts. They just undo the 4 screws on the sides of the panel and the ones holding the switch in place. Now they pull on the top of the panel, and, because the casting is so thin at the the topit cracks. This is the when you loose your ground. If that is the problem, then you have to replace the panel. Hope this helps

[Juliet P.]

The wiper switch ground is through the panel?

Bruce, are you saying that the ground for the wiper switch is through the panel itself, and if it's cracked in that oh so typical spot, that you can get a bad ground!?!? Hey, if I'm interpreting your post correctly I think you might have solved my intermittent problem AND given me an excuse to bump a new console panel up higher on the "to buy" list. ~Juliet


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[bruce]

Re: The wiper switch ground is through the panel?

Juliet This is a problem you will encounter, and it's fairly common and an easy fix. Some times the door works/then doesn't. The first place, along with the switch is the place to check. Also if the wiper door opens but wipers don't move, check to see that the override(under steering column)hasn't been moved by accident

[Shannon Burgess]

It's gotta be the ground!

Don and Juliet,

I had this exact problem on my '69 when I bought it. All the vacuum stuff worked fine from below the steering column, but the wipers wouldn't work from the wiper switch unless it was pressed in to activate the washers. Of course, since all the washer hoses were gone, that made for a mess under the hood as the washer reservoir was emptied all over the firewall

I ran a "bubba" fix and ran a ground wire from the wiper switch mounting screw down to the shift console support until I could get a new gauge bezel. That got me past the state safety inspection and worked flawlessly.

Shannon

[John L.]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

My 72 was doing just this same thing and I found that the plug on the wiper switch had be placed on backwards by the previous owner. It will go either way. I took the plug off the switch and turned it over and put it back. Everthing has worked perfect since. May be your problem?

[John Woods]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

Don: As crazy as this sounds, make sure that you don't have the wiper switch harness plugged in upside down onto the switch that's located above the instrument cluster. I am traveling or I'd look at the print and/or my car and let you know which side the right color wires line up on, but I can't do that. The plug is keyed but it can be inserted both ways. Try it and let me know.

[Jim T.]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

I broke my original guage cluster panel at its weakest points accidently when I had the windshield and the top dash out of the car. Anyway everything put back together its not noticable unless you look real close. I have not experienced any problems with the operation of my windshield wipers yet, but will keep the grounding problem information for future problems of the wipers.

[Don]

Re: 1970 Wipers/Wiper Door Inoperative (KW=missile

Thanks, Jim!! Problem turned out to be the wire connector on the back of the wiper switch...it was installed backwards (which is easy to do. Remember this: TOO BLUE TO PASS (double (2) blue wires to the passenger side). All's well with this 70 convertible!! Hope you have no problems with yours!

Don