[schlitzman]

Just got a '67 Grand Prix convertible. Car has cornering lamps. Lamps work, but do not get power when directional switch is on, w or w/o headlights on. Is this a switch problem (wrong switch) or something else. I have the '67 Service manual but can't find any reference to cornering lamp wiring. Any ideas/hints would be greatly appreciated.

Thanks,

Schlitzman

[stevep]

Make sure that it has the correct turn signal switch. It should have an extra pigtail w/2 wires coming out of the column. If the switch failed on the prior owner, he may have installed a non cornering light turn signal switch or installed a different column.

[Coach]

+1 Mine had the wrong one when I bought it

[GpFreak]

Do the signals cancel after you turn a corner? The signal switch is a common issue and like Steve said make sure you get one for a cornering lamp car. The switch is bad in my '70 and I've caught myself a couple times now driving with the right signal on, I must be getting old!

[north]

also if the car has been apart for painting you often lose the ground, especially if they got paint on the inside of the fenders, those lamps ground to the body.

Put on the lights and the turn signal with the ignition in run and see if you get 12v at the wire leading to the unit (the same side as the turn signal of course), if you get juice then all that's left is the bulb or the ground. If you don't get juice then its probably a bad or incorrect turn-signal switch or some bad connection somewhere.

[schlitzman]

Thanks all,

The cornering lamps work, as determined by supplying a 12v source. There just isn't a 12v supply to them when the directional switch is applied. Looks like I need to replace the switch if I can't jump a coordinated turn signal voltage.

Is there a special switch I need to get, either a Boyne or GM?

Bruce

[stevep]

Do you have a parts book that you can look at? Do you have a tilt wheel?

I think that it is the Boyne switch and if I remember correctly, it's the red one.

Just to be sure, is the 2 wire pigtail connected to the directional switch?

[north]

Before buying a switch make sure the two extra wires on the switch under the column are connected and that things are wired right at the junction behind the fuse block.

[schlitzman]

Thanks, Steve and North.

Steve, yes, the car has a tilt wheel. Where do I look for the 2-wire pigtail you reference?

North, I'll remove the junction box and examine connections.

Bruce

[stevep]

The pigtail should be right next to the main turn signal switch connector coming down the column.

[gtoric]

Originally Posted by schlitzman

Thanks, Steve and North.

Steve, yes, the car has a tilt wheel. Where do I look for the 2-wire pigtail you reference?

North, I'll remove the junction box and examine connections.

Bruce

With your tilt column, there is a chance that the ribbon harness that runs down the column has the wiring insulation chaffed off the wiring to the cornering lamps. Every time the wheel is tilted, the harness is moved up or down the column. With enough tilt cycles, the harness can be grounded onto the column.

I had a problem with brake light operation, and it turned out to be harness grounding inside the column where the tilt pivoted.

[schlitzman]

I did check the switch and it does have a pig tail. Except, it has three wires, not two. No power from the pigtail when either turn signal activated. I will check for potential short per "gtoric"

Many thanks.

Bruce

[Mike Pemberton]

Had a new TS switch which you can buy at:

SHEE-MAR, INC
POX 179, Longmont Colo 80502 Part# SM 229 GM

Mike at PY rebulit my headlight switch and I seperately grounded the corning lamps back to the harness grounds at the core support where they come out of the headlight harness. Took a bit to figure out what was going on. The grounds are most key as one was working and the other one did not in all sorts of hook up trials.

Need to call please do.

Mike Pemberton
510-501-6299

[compsur]

Noticed the reference to 2 wire pigtail for corning lights, actually its a 3 sire pigtail setup. Believe the middle or brown wire is live or power with the 2 outside wires, one for left and the other for right. Just replaced the Boyne switch and cant get those lights to work. Worked briefly when testing but once i had the switch installed, they no longer work. Brown wire doesn't show polarity, really stumping me.

[north]

Don't forget that you need the parking and/or headlights to be on to power the cornering lamps. Interestingly, while you need the ignition in the run position to work the turn signals the cornering lights work without the ignition switch on Do the turn signals themselves work? If so then make sure you have a ground to the body with the lamp housings. Also check the bulbs themselves. If you aren't getting power to the brown wire on the signal switch then it may be the headlight switch is defective or incorrect.

Last point, if you added the option, I've noticed that most non cornering lamp cars in that era (but not all) had the extra wires needed in the dash harness (some assembly plants cut the pigtail at the column though) and most cars didn't have the extra wires needed in the forward light harness. Strangely in 69 pontiac clumped the hideaway and corner light functionality in the same harness (to reduce the number of different harnesses I imagine) so a 69 LeMans for example ordered with cornering lamps has the vacuum hoses needed for GTO hideaway option in its forward lamp harness and a GTO ordered with hideaways has the wires in the lamp harness for corner lamps even if it wasn't ordered with them.

[compsur]

At first i didn't realize the parking or headlights had to be on for them to be in hot mode, my 81 Bonneville doesn't require that. So I spent most of day scouring the electrical diagrams trying to work backwards with a circuit tester as to why i had no power on the brown or middle wire. I'd replace the fuse, the left side would work and when switching to the right, nothing. After burning through 3 fuses, i realized the repo Boyne signal switch being the problem. Its now the 2nd switch I have had to replace. NOS versions are still available, but after 50-60 years, the plastic becomes brittle and has a tendency to break, like the first one i replaced and considering the price, don't want to risk it. The one in there now is a repop version that i fitted a few months back, i recall it was a great price, made in China would be my guess, but still the best option. Once in hand back to treading those wires down the column again, hope 3rd time is a charm.