Hello tailgate masters,

I rewired the tailgate last night in the hopes of reviving the liscence plate lights. I ran into a couple of things that don't make sense.

My method is one that I got here in the archives basically I moved the wires from the passenger side to the driver's side, rerouting the four wires for the wiper/electric lock/plate lights over to the other side up the hatch and out the access hole and into the roof both harnesses are now not routed through the hinges, it came out good, here are my problems:

1. The harness for the driver's side are two wires for the defrost, they get juice, I tested them. When I removed the interior panel they were just dangling and weren't attahced to any thing so where inside the hatch do they connect, I've looked over and over and just can't figure it out I don't see the spades that they go on, I've looked along the edge of the glass and I don't see the connector.

2. The plate lights aren't working, the bulbs are good I tested them, it seems to be wired up completely I don't find any stray unconnected wires.

I'm wondering if there is an interconnect between the defrost and the junction at the wiper motor....the defrost wires aren't long enough to reach where the junction is at the wiper motor, perhaps something is missing.

The wiper is working however, since the car will be inspected soon I need to have the liscence plate lights functioning. Is there a quick and dirty yet fully functional way to attain this? I can easily solder some wire in, any suggestions?

As always all help is apprecaited.

Your comrade in tailgating,

Josh Lasserre
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Best Regards,

I'm not good with electrics (fffizz, bang, arrrgghhh is the usual sequence of events when I try to change a bulb) but I had a right old time with my number plate lights also. After a few hours of fannying about I discovered that the current runs through the supply wire, through the bulbs and goes to grounds though the fitting to the body of the tailgate. This is blindingly obvious to normal people but to an electrical spode like myself this cam a a revelation. Unfortunately, the tailgate is prone to corrosion at the cutouts for these lights and this was affecting the flow of electrons. I made a new earth lead to run from the light fitting to ground (I used one of the mounting bolts for the rear wiper motor for this) and it's been OK ever since.

I hope this helps,

Big Rich.
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'86 245, B230A. 161k. Old 200s never die, they just live on in other cars.

Big Rich makes a really good point that I've overlooked or taken for granted. Your tailgate MUST be grounded for all this stuff to work right.

Very often the grounding wire in the hinge is the first to fail. After that, your tailgate achieves some unknown, variable grounding through the hinge pins, shocks, latch, and so on. But these are unpredictable and variable and can change when you hit a pothole.

EVERY TIME I repair or replace a tailgate harness, I always run an extra ground wire to be sure the tailgate's grounded. I run an extra piece of flexible test lead wire from a grounded bolt near the wiper motor, through the hinge, to a convenient grounded spot under the headliner.

This might sound like "belt & suspenders," but better two than zero.....
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Don Foster (near Cape Cod, MA)

"...two wires for the defrost, they get juice, I tested them..."

Should be only one. The other side of the defrost grid goes to ground.

"...looked along the edge of the glass and I don't see the connector..."

The wires from the grids (one each side) are usually tucked under the gasket, but then sneak out from under the rubber gasket and go through an oval grommet. These are on the flat, horizintal lip or "shelf," about 1" wide, between the lower edge of the glass and the top edge of the trim panel. These grommets are very visible. One of the wires goes to a ground connection, the other connects to one wire from the hinge harness.

"...plate lights aren't working, the bulbs are good I tested them..."

Do a little circuit chasing: Using your voltmeter or test light, find the ONE wire coming into the tailgate that shows 12 volts with the parking lights on and 0 volts with the lights off.

"...if there is an interconnect between the defrost and the junction at the wiper motor..."

The defrost grid might be grounded there.....

"...need to have the liscence plate lights functioning...quick and dirty yet fully functional way to attain this?"

Find the feed to one parking light and tap into it, runing the other end to the license plate lights. This, of course, should trigger the "bulb out" indicator because you now have unbalanced currents to the tail lights.
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Don Foster (near Cape Cod, MA)

Don,

Yep I found the grommets but look like the wires have been 86'd, they're not sneaking out through the hole I'll have to solder in new wire get it going. No luck on the one hot wire that goes off with the lights. With the ignition on the only wire that goes hot is the black wire. Perhops this thing is wired wrong,

I'm sure it's been monkey'd with. It's got a power trunk release but no button up front. The funny thing is, is that the tailgate is the same factory color grey as the rest of the car even under the panel, it's not like it is obviously a different hatch though I think the handle is from a later hatch, maybe the guy found another grey wagon, I dunno.

How about this, if I run a wire from each hot parking side to the plate lights in an attempt to balance it out, would that work?


Josh
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Best Regards,

The wire that is live with the key on is, I think, for the wiper motor. A second wire to the wiper goes live when you flip the switch on the wiper stalk.

"...if I run a wire from each hot parking side to the plate lights in an attempt to balance it out, would that work?"

Probably, but that would be Mickey Mouse -- those plate lights are somewhat unreliable, so I expect the the warning light would be winking at you always. Anyway, you wanted to do something just for inspection -- and then you were going to fix the car right.

To really start your troubleshooting properly, map out the wires at the terminals in the connectors under the headliner (and it's easy to do). Figure out which wire becomes live in what situation, and then troubleshoot back through the harnesses and into the tailgate. It's unlikely that your car harness is at fault.
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Don Foster (near Cape Cod, MA)