[DMC24guy]

A suppose a little background info would be helpful.

I have a 77 Grand Prix base model with a 301:


I recently purchased the following gauge cluster out of an SJ model, which includes actual gauges rather than idiot lights:



My plan was to swap out the existing cluster and put this one in. I purchased all the sending units and thought all would be good. However, it wasn't.

Once I had the old cluster out I saw that "seat" that it sits in did not have all of the gold clips which the studs coming out of the gauges would go into. As a matter of fact, I had to remove the idiot light bulbs to get the new cluster to sit properly. Once it was in, like I had suspected was going to happen, the Volt gauge, oil pressure and water temp gauges were not working. Everything else did however.

I didn't want to believe that GM would actually spend the time and money to produce two different setups for the gauge cluster, but sure enough.

My question is this:

1) I didn't remove the black plastic seat which the gauge cluster sits in, so I don't know if the necessary wires are back there just unused. That would be to simple though, so I imagine that's not the case.

2) Is there a completely separate harness for the SJ models with the Rally gauges? Meaning I have no choice but to find that too...

3)Since I have the sending units, is there anyway to do my own wiring to make these gauges work?



Thanks!

[77GP]

I got into a mess with mine when I did this switch. I think you need the seat or circuit board. I had the hole set including wiring harness. When we were done I had headlight and wiper problems. Took it to an electrical shop and they fixed it. I like my tach and guages but it came at a price. Must be an easier way. Your new pod should mount in existing one or at least you would think so. Good Luck!

[bastard]

1. This wasn't a question, it was a statement. But the wires aren't there if the car wasn't originally equipped with the optional gages. You'll need the circuit board and harness for the gages you want to install.

2. Yes. It isn't necessarily trim level specific as much as gage option specific.

3. Yes, depending on your level of electrical/electronic troubleshooting and repair skill it is entirely possible to wire up factory gages with non-factory style wiring. But it has to be right, or you could have a flaming hot GP in a way you really don't want.

If this doesn't answer your questions to your satisfaction, you may want to try one or both of the following:

Poncho Pride forum dedicated to all mid-seventies Pontiac models.

A Body Site forum dedicated to mid-seventies GM A bodies.

Both of these forums are monitored by people with a lot of experience with the GP style dash, which was used not only in the GP, but also in the Grand Am, Can Am, and Grand Lemans as well.