Wires behind intrument panel

[wlkelley3]

My car has been apart for a while and I'm now putting it back together - a lo-o-ong restoration. Anyway I have the dash and intrument panel back in now and I'm trying to reconnect all the wires. I have a small wire bundle that comes from the center instrument panel leading over to the drivers side. It is 4 wires. Two are thick and the other two are small. The 2 thick wires have eyelets on them and the 2 smaller wires have female plug. One of the thick wires is solid red (or maybe orange), the other is red w/white stripes. One of the smaller wires is brown, the other is yellow w/ black stripes. They originate from the same wire harness and the 2 smaller wires seperate into their own harness, the 2 bigger wires seperate on their own at the same location. I hope this explains it well enough. I would like to know what they hook to. I can't find any blank locations for them (admittedly I didn't spend a lot of time looking, it's a bit chilly in the garage and I just finished bolting up the steering column and hooking up the plugs to the fuse block ). The car is a 70 Opel GT and the original wiring harness is in the gray sleeves. I mention this because most of the GT's I've seen the wiring harness is wrapped in black tape and I'm not sure if it makes a difference, as in possibly a slightly different harness. I attempted to try to tag & mark everything when I disassembled the car a few years ago but all my marks have come off and I didn't have a digital camera at the time (I have 2 now). I'm hoping someone else has gone through this and can lead me to where the wires go.

[sawdust]

Try this link

[GTJIM]

I am in a similar position - but have a spare dash with the wires still on the instruments. Way back in the corner of the workshop at the moment ... must dig it out and start again. My GT is a 1972 automatic, which may have different wiring though.

One thing you MUST have is a copy of J J Wheatley's wiring diagram - often for sale on eBay.

There are different looms for early and late GTs so you need the correct loom to start with - or make the alterations needed.

[Anonymous D]

The pair of thick red wires with eyelets, go to the threaded posts on the back of the amp/oil gauge. (They're part of the alternator charging circuit, and are routed there to read on the gauge). Solid red connects to "L" and the striped wire goes to "B", as inscribed on the rear of that gauge.

Of the smaller wires, the brown wire is a ground. Not being able to see the back of your dash panel, it's a guess that it might connect to the rear of the speedometer.

The yellow/black wire might need to be deduced, as the factory schematic shows that color is used in more than one circuit: Headlight relay (probably not), brake pedal switch (doubtful), Right turn signal indicator bulb (maybe), front horn circuit (doubtful), or an alteration by a prior owner (possible).

In the future, I recommend purchase of the wiring schematic done by JJ Wheatly (about $30, including shipping), prior to starting any rewiring work.

[namba209]

O.K. the two thick wires (10 Gauge) Red and Red/White come from the ammeter and go to one of the four studs in the center of the fuse panel. Red/White next to the other Red/White wire, Red next to the Red wire, diagonally across from the Red/White wire. The Brown wire with a female spade lug could go to the emergency brake handle at the center base of the instrument panel. I couldn't find a Yellow/Black wire on my DESTEC schematic. HTH.

[Nathan Acree]

The thick Red and Red/White stripe go to the ammeter, there are studs on the ammeter for the ring terminals on these wires.

I don't have a schematic right at hand but the other wires in that bundle may be for the oil guage (the ammeter and oil gage are in the same housing).

I'm sure someone will provide a more complete answer-

-Nathan Acree
Albuquerque New Mexico

[ungermm]

I have a spare harness from a 70 GT with those colored wires you describe in that location. I'm not 100% sure (because I didn't label them), but might the smaller wires be for the oil sensor on the engine? They go through a grommet on the top drivers side of the trans tunnel to the engine. I know this to be the case for a 72, but those are different colored wires.
Jerry

[markandson]

http://www.opelgt.com/photopost/data..._Schematic.pdf

This is a link to a color Schematic for a '73, maybe it will help, it is a pdf

The only Y/Bk wire I see goes to terminal 85 on one of the headlight relays.

[wlkelley3]

Thanks to all. You've all been a big help. I thought that schematic was someplace on this site. Just couldn't find it. Looks like the instrument panel has to come out again to hook the wires up to the back of the gages. Hopefully it will go a little better the second time.

After I get the dash hooked up correctly, all I have left is install the seats, glass, engine/trans and then get it running. The hard part. Already have it's debut showing schedule on May 31st. I have a little time.

Wendell

[ungermm]

On second thought, the two smaller wires may be for the back-up switch on the transmission which go through the grommet on the trans tunnel.

[hrcollinsjr]

Wendell,

Glad to hear you're finishing it up. Looks like some of the group just about have your wiring questions figured out.

Harold