Idiot lights to gauge/tach cluster swap...1978 LeMans

[TylerW]

Hey everyone:

I know this question has been asked a few times in various forms but there's never been a good answer:

My '78 has the idiot lights with those unreadable silver gauges.I happen to have a tach and gauge cluster I salvaged out of an '86 Bonneville, of all places.

What I need to know is what pins need to be changed so that everything works. I've done this swap on several Cutlass' so I'm familiar with replacing senders and running a tach wire, but this is the first Pontiac and there's precious little info.

Any tips or links would be much appreciated, thanks!

 

[TylerW]

Well, since 59 people offered no advice, I figured it out myself:

It's a very simple swap. All the wires for the 4-gauge cluster on the right are in the proper locations as-is.Plug and play.

On the speedo/tach cluster, 2 wires needed to be swapped around and one oulled out and taped up.THIS IS ON A PRE-1981 VEHICLE.IF YOURS IS 1981 OR LATER YOU WILL MOST LIKELY ONLY NEED TO PULL AND TAPE THE WIRE I DESCRIBE.

The 2 wires that needed to be swapped around on my application were the hi-beam indicator and the fasten belts light. That is because between 1978 and probably 1981 they moved to different spots in the small center panel. The older cars have the hi-beam in the center behind the Pontiac logo and the fasten belts in another spot to the left.

Those 2 swap places in the later cars, but the printed circuit does not change at all.Simply swap those 2 wires place for place.

Also, if your car came with a clock like mine did, one of the wires has 12v to it constantly and needs to be pulled out of the connector and taped up since there is no use for 12v on the non-clock cluster if that's what you swap in. If you retain the clock then retain the wire of course.

If you swap in a tach like I did, then you will have to ID the negative terminal of it and run a wire from there to the TACH terminal on the distributor cap.Be sure to set the slide selector on the cluster to 6 or 8 cylinders depending on which your vehicle is.

Simple as that..good luck.