So I've been working on repairing the steering column in my 88GT for a few months now (on and off). I gave up on the original column. The "key" shaped piece of metal opposite the lock cylinder had broken, so I tore down the column until I could get the piece out. The problem is, I likely went too deep into the column (further than I should have), and the two bearing races would not go back and stay in place in the column. I gave up and grabbed another column from my spares bin, but I hadn't noticed that a wire harness connector had been cut or ripped off the column. These wires go to the turn signal stalk base.

Note the color of the wires. This wire ribbon has 5 wires, instead of the 3 wires in the 88GT column...
Replacement column wires


Same part from the 88GT column. Turn signal base visible at center of picture


I've been going through the factory service manual, and can't find either the 3 OR 5 wire ribbon in the wiring diagrams. I looked in the "turn signal" section as well as the "wiper" section. If I can't find the wiring diagram that covers this, I will likely transplant the turn signal base with wire ribbon and connector to the original column for the 88GT, but if I can solder in the other ribbon and connector, it should work.

Any ideas?

I believe the extra wires are for cruise control. Did your 88 have cruise control?

All GM vehicles w/ same type Round Columns & many more...
Cruise Lever has Cruise wiring going directly to the buttons & small "weird" 4 wire connector.

2 types, maybe more, of Windshield Wiper shown above...
1 is for non-delay setups.
2 is for delay setups w/ 1 or more wires for delay feature.

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quote Originally posted by IMSA GT: I believe the extra wires are for cruise control. Did your 88 have cruise control?

Yes. The crazy thing is, the turn signal stalk from the second column *does not* have cruise but more wires. The 88 has cruise but *fewer* wires. Still can't find either of these wire ribbons in the FSM.

Success!

I transplanted the switch mechanism/wiring ribbon and the switch base/wiring into the replacement column. Installed the column back in the car and everything (except cruise control, will test on the lift or a road test) works.

Thanks for the help, folks!

*sigh*, the problems continue.

After transplanting the mechanisms and wiring (turn signal unit and wiper base with wire ribbons to both) from the original column to a new column, the car starts and runs but there's NO power to the turn signals...even at the fuse box. I had the battery disconnected during the entire r-and-r of parts until everything was hooked up. I'm still going over the wiring diagram to figure out what might be preventing power from reaching the components. It's something of a mystery because, according to the wiring diagram, some of the items on the same power wiring work while others do not.

Note that there's no power to part of this circuit, but other components have power:



Based on this diagram, the turn signals, gauges and ECM IGN (ignition) are on the same power. The turn signals do not work, but the gauges work and the car starts. I can't find a reason why part of the circuit has power but the other part doesn't.

Edit, add:

These things have NO power
Brake lights
Turn signals
Stop-Hazard
Pontiac logo in tail lights

These items have power
Instrument panel
Headlights/high beams
Courtesy lights
Starter system
Fuel injection
Fuel pump
Radio
Running/marker/tail lights (aside from brakes and turn signals)

[This message has been edited by fierobear (edited 12-24-2023).]

Ooooof! I found the problem.

I went through the factory service manual, going over all of the electrical diagrams. I traced the source(s) of power for the turn and hazard circuits. Then I checked the fuse box...the Stop/Haz fuse was MISSING. WTF? I'm the only person who works on this car, and I'd have no reason to remove the fuse. Have you folks ever had a fuse simply fall out and go missing?

Anyway, everything is working now. Thanks for all of the input.