Chris289

A question regarding the 68 Cutlass Convertible dashboard. Before I stripped the car the wipers worked, just about. The washer pump didn't work and had a modern bottle installed. I've removed the wiper motor and re-painted the painted parts of it but didn't strip anything down on it, I did replace the built in washer pump internals though. When I stripped the dash down and removed the wiper switch there was a wire wedged between the switch body and the firewall to act as an earth. This is obviously some sort of crap repair.


My question, is the body of the wiper switch body meant to be earthed? If it isn't earthed will it not work? The wiper motor is back on the all the wiring back in the car, the dash is not back in yet but the switches are but the wipers don't work.


Also, on the original plastic part of the dash, the lower part, there was no metal pieces on the back, every electrical part had its own little earth wire going off to various parts of the firewall to earth things out.


The new lower dash part I got has a shapped piece of steel on the back that goes onto the rear of the ignition barrel, the ciggerette lighter and the right gauge, this looks factory but that's the only piece on there. Should there be more steel on the back of the plastic part to earth the other 2 gauges and 2 earth the headlamp and wiper switch?


Also should the headlamp switch body be earthed and is there meant to be a separate wire that's not part of the plug that goes onto the headlamp switch body? There is a small tag on the side that sticks up that looks like a spade terminal could plug onto it. I've gotten all the lights working now via the switch after rebuilding it but can't get the switch to operate the courtesy lamps.


Any help would be appreciated it,
Chris.

allyolds68

Here's the wiring diagram for the switch. If you'd like the whole wiring diagram send me your email address and I'll send it to you. There's a metal ground strap that's attached to the dash that the switches ground to. You have to make sure the jumper wires between the gauge pods make ground somewhere also because they are what ground the strap. The ground wire details are in Section 1-3 of the Assembly Manual

joe_padavano

The plastic dash has a sheet metal ground plate that connects all the switches to ground (earth). There is no separate wire required - the act of tightening the mounting nut on the switch completes the ground path through this plate.

The wiper motor uses a brass ground strap that bridges around one of the rubber mounting grommets. If this strap is missing, the wiper motor will not be grounded and won't work.

Chris289

Ok cool. Does anyone have a photo of the rear of the plastic dash piece as it should look. This way I can fabricate the rest of the grounding metal parts.

Yes the brass ground strap is present on the wiper motor. I did powder coat the mounting bracket that goes on the rear of the motor onto the firewall and repaint the firewall, mayby the motor isn't making a very good earth against the firewall through the screws that hold it on because if the paint. I'll check this out next aswell.

allyolds68

The ground strap and ground wire I have arrows pointing to just continue ground to the gauge pods. This dash was apart at least once since I removed it so it may not be completely original.

Ground is carried to the dash via the metal ground strap that I have an arrow to on the right. It makes contact with the metal dash and has speed nuts attaching at that point. (see the assembly manual section 1-3 page 111)

allyolds68

See ground strap, lower right:

allyolds68

Engine to Cowl Ground Strap Detail. This little strap grounds the whole body. Without it nothing in the body or dash will work right. And of course the main ground from the battery to the front of the block must be in place as well

joe_padavano

Beat me to it - I was just about to upload the same picture from the CSM. Note that the ground straps are captured under the studs that hold the plastic dash to the metal inner cowl. This is how they get grounded to the body. There is a separate ground wire that runs between the gauge pod mounting screws.

Chris289

Yep that confirms the dash bits then, the ground straps for the headlamp and wiper switches are missing and for the left and middle gauge. I'll have to fabricate something up.

All the engine bay wiring I've re-done except for the wiper motor, there was nothing wrong with that loom so the engine to firewall strap is new and improved upon the original design. Checked the wiper motor itself has a ground tonight and it does. I think I'll have to wait to get the dash back in to continue working this problem out and so that the switch is grounded properly.