ronarndt

Heater and horn now work on 68 convert. Two more bubba modifications restored to new. New heater core, hoses actually attached, blower fixed and the heater gives tons of heat- enough for a quick drive in 40 degree temp. The horn works after removing extra wiring, bad horn contact and replacing a K-mart horn with actual GM horns and proper grounding wires.


Still working on the @#$%^ 68 windshield wipers. Washer relay clicks, motor field clicks, but new motor does not actually run. Symptoms of door limit switch, but even jumping the switch does not work. Back to the wiring diagram and Wilcox instructions again. Everything seems to be hooked up properly. I may have to spring for a engine wiring harness to correct one bad wire somewhere that is not evident.

Andy Tuttle

At least there is some forward progress! Keep up the good work Ron!

Rescue Rogers

Check continuity through the door limit switch, make sure its open all the way. Check for ground on the brown wire that goes to your maintenance switch under the dash. Go to the wilcox trouble shooting and check for proper power on all your lines. Then do the bench test with the motor installed. Mine suddenly stopped due to weak vacuum not openning the door fully. Did the above in the reverse order to find my switch wasnt closing. Good luck. When I unbubba'd mine I had to replace all the switches and motor.

You may not have a good ground at the maintenance switch. Bubba didnt like the dash ground wires in mine so he didnt hook them up when he put in a new harness

65GGvert

Jumpering across the ws wiper switch won't make it run. The switch provides a ground to proper wires for correct speed. Make sure the switch case (mounting holes) for the wiper switch are connected to a GOOD ground. Mine didn't work and the console plate the switch was mounted to was not grounded. This is noted in the Willcox diagram.

Rescue Rogers

I thnk he jumped the limit switch. Good call on grounding the wiper switch. I forgot to mention that.

ThumpingLotus7

I just went through this pain on my 71. Remember power is always on and the wiper switch grounds different parts of the system, there is no power in the switch, the wiper motor (when the wiper limit switch is closed) always has power and the switch just grounds the circuit . Here is what I would check based on my 71.

Ground:
1. Ensure that your wiper switch is grounded, on my 71 it grounds through a tab on the bezel which can if improperly installed not touch and therefore not ground.

2. Ensure that you test the continuity of your wiper switch. Wilcox has a great video showing all the states of the switch using a multimeter.

3. Make sure the black wire which screws in via a spade to the wiper motor housing is a good solid ground.

If any of these 3 grounding tests fail this will explain your failure.

Now for testing power

1. Ensure the wiper cut off switch **** is rotated towards the passenger seat. If the switch is off there will be NO power to the motor period.

2. Testing the wiper door limit switch for continuity is not enough, mine had continuity but couldn't pass enough amperage to run the motor. Therefore force open the wiper door, disconnect the limit switch, turn the wiper switch to on, and bridge the contacts that the limit switch would normally connect, I used a set of needle nose pliers.

3. Power runs to the motor through the yellow middle wire in the three way connector, if there is power there and you have fully confirmed your grounds then the motor need to be rebuilt.

i can send pixs on request, or describe how to test grounds or for power

ronarndt

Thanks for suggestions for the w wipers. Most have already been done. Dash bezel and wiper switch are grounded in two places. Motor (brand new and bench tested before installing) is grounded thru the spade connector to the wiring harness ground wire going to the starter ground. Note that the wiper door is removed (long hood) and the wiper door limit switch is permanently bridged contact-to-contact with a 14 ga wire loop in the plug to the limit switch. However- "Check for ground on the brown wire that goes to your maintenance switch under the dash". How is this switch grounded? I wondered, since my new wiring harness attaches to the switch, but the switch is just fastened to the lower dash near the steering wheel (no separate grounding wire). I do not think this panel is grounded, since all of the instrument illumination bulbs for the speedo and tach on this panel require a dedicated ground wire to the case of the speedo and tach.. This may be the problem, since when the wiper switch is turned on, the motor field circuit can be heard clicking on and when pushing the "wash" on the switch the electromagnet in the wash circuit can be heard clicking on. The dash "maintenance" or "cut off" switch is turned clockwise toward the passenger side, but turning it the other way makes no difference. I will run a dedicated ground wire to the cut off switch and see what happens. Also- any suggestions how to keep the **** from falling off? I've tightened the allen set screw, but it holds only temporarily. I'm ready to glue it in place.

D_Williams

I was about to drop some knowledge before I realized that the 68 wiper wiring is different than 70.

If the end result is the same, when the car is on, then the yellow wire to the wiper should stay hot and switching the ground on the blue and green wires at the wiper change the speed from off -> low -> high

On my 70, when the wiper is off, the green wire is grounded and the blue wire is open (not connected to the ground)
Low speed, both the green and blue wires are grounded.
High speed, just the blue wire is grounded and the green wire is open.

Have you checked this?

Rescue Rogers

Ive got an early 68. The maintenance switch has a ground spade on the dash frame that the switch is attached through, then the harness should have a ground plug specifically for that spade. If its not there you can do as you said and create one.

ronarndt

RR- I will crawl under the dash when I get home (my neck hurts already). My recollection is that there was one wire labeled on the dash wiring harness for the maintenance switch and one spade connection on the switch. The switch is mounted thru a hole on the dash panel and secured with a threaded thin nut. I do not believe that part of the dash is grounded to anything, so how is the ground circuit completed? Is there supposed to be another ground wire going to a metal part of the frame?

ronarndt

[QUOTE=D_Williams;1591506384]I was about to drop some knowledge before I realized that the 68 wiper wiring is different than 70.

Yes, one year only for this design. I think they changed it due to the dealer service mechanics going insane trying to figure out how they worked.

ronarndt

I just checked the Wilcox wiring diagram which shows the "mounting bracket" for the bypass (maintenance) switch being grounded, thus the switch would be grounded thru the mounting bolt and nut. However......I don't remember there being a mounting bracket there connected to anything that was grounded. Will check if bubba removed it when I get home. I'd like to remove a few parts from bubba if I could.

Rescue Rogers

My switch had the specific wire to the harness and the harness grounded above the dash to the bird cage and again on the drivers side to the bird cage above the dash vent tube.

The bracket had the tab for the connector

ronarndt

When I had the panel out for the speedo and tach, there were ground wires for the case of the speedo and tach, and plugs for the headlights and ignition switch, but nothing going to the bottom of the panel where the bypass switch for the wipers was located, except the wire to the harness. So- the switch connected to the wiring harness is attempting to complete the ground circuit, but it just dead ends in the fiberglass without anything to ground to. All of these inter-related circuits are making my head hurt.

Rescue Rogers

You may have to create a ground for it. Splice into the tach ground and run it down to the switch or get a long ground and run it from the top of the bird cage to it. Sounds like its a major source.of.your problems

ronarndt

I just checked and the metal bracket holding the wiper maintenance switch is not grounded. Also, the switch is so worn it does not have continuity when it is supposed to be on. Will order new switch. However- since closing the switch just completes the ground, to check it out I used a jumper wire to go from the maint switch wire to a known ground. The wire going to the maint switch is hot. It sparked but did not blow a fuse like a dead short. Should there be power to this wire? Wiring diagram shows it brown, not black like a normal ground, but I can not see where it is drawing power and this is serviced by a new wiring harness, so no bubba in this wiring. This does not make sense.

Rescue Rogers

It should be the ground for the wiper system. Check for continuity to the wiper door switch. You will get a little sparking when connecting a live circuit to ground, but not noisy arcing.

ronarndt

Isn't the wiper maintenance (bypass) switch the one if you forget and leave it on in the service position, it will drain the battery? Where does the power enter the ground circuit? Cars that have a warning light for the switch left on get power for the light thru backfeed, but backfeed from where? everything I see in the wiring diagram is a ground circuit.

65GGvert

I don't know about a 68 being wired differently, but every maintenance switch I have checked (mostly 72's) feeds 12v through it up to the wiper door safety switch. If for some reason your car is the same, and you ground that wire, you're in for some unhappy times. The wiper door safety switch that you bypassed is hot all the time. Do you measure 12v there when you check?

ronarndt

The wiper door limit switch is hot one side and when the switch closes hot both sides. What I am have difficulty with is on my wiring diagrams what we are calling the maintenance switch has the wiring harness wire going to the wiper door limit switch on one pole and a dead ground on the other pole of the maintenance switch. Where does it get power and is grounding that hot wire (when the maintenance switch is closed) the proper set up?