So I purchased the Fusick Engine Main and Dash Rear Harness, 1968-69 Cutlass and 442 (http://www.fusickautomotiveproducts....number=8906983) a year ago because that is what I thought I needed as the car did not originally have a rally pak. Well I'm getting around to the dash wiring finally and I notice there are issues with it. So I would like to just get the dash harness with the rally pak (http://www.fusickautomotiveproducts....p?number=13250) because then I would know I could trust it all.

So my issue is, what are the differences between these two:
Engine Main and Dash Rear Harness, 1968-69 Cutlass and 442 (http://www.fusickautomotiveproducts....number=8906983)
Engine Main and Dash Rear Harness, 1968-69 Cutlass and 442 with Rallye Pac (http://www.fusickautomotiveproducts....number=6299313)

What all will I need to do to get non-rally pak Engine Main harness to work with the rally pak dash harness?

thanks!

 

The one difference I am aware of is the brown tach wire with inline two amp fuse is imbedded in the rallye pac harness.

 

This diagram will help you change from idiot lights to gauges. I did this to my '68, which originally had idiot lights, and it worked fine. As well, for 68-69 anyway, I believe the brown tach wire was separate from the main harness. At least that's the way it was for my '69 that came with gauges and tach so that's the way I wired my '68. The job is a bit painstaking but it can be done. It helps to have the front seat and the steering column out. Randy C.

 

Thanks for posting, Randy. For my '68 4-4-2 I used another version of this instruction sheet that does not have the hand written info in the upper left. Did you do the hand written part? Mine is still on jack stands, so I have not had opportunity to start it and verify operation.

 

Yes, I wrote that in. The green wire is part of a circuit check program. When you start your car with idiot lights, the temp light comes on momentarily before it turns off. With the green wire connected and gauges, the temp gauge will peg every time you start the car and then return to the temp reading. Some people say that constant pegging will eventually ruin the temp gauge. Others say it doesn't make any difference. I just wanted my car to be the way a car with gauges should read and that means I didn't want the temp gauge to peg. Disconnecting the green wire from the ignition switch harness (that's the harness that plugs into the ignition behind the dash), taping it off and grounding that position in the ignition switch harness, the temp gauge will do exactly what it is supposed to do.

Randy C.

 

So does the position in the ignition switch where the green wire “have” to be grounded for the temp gauge to work. I disconnected the green wire but did not ground. My temp gauge is not working. I am. Wondering if this could be a possible reason.

Thanks Tim

 

Thanks for clarifying, Randy.

Cheers!

 

Hi Tim,
I don't think a missing ground wire at the ignition switch would cause the temp gauge to not work, but my electrical smarts are pretty basic. In a worst case the temp gauge might peg and then return to normal but that should be it. I would add that ground wire for starters but I don't think it will make any difference. I think the problem is either the gauge itself or the connection between the gauge and the sender unit. Just guessing on my part, though, so hopefully someone else will chime in!

Randy C.

 

I did this modification and did not add the ground wire, and my temp gauge is working fine. No issues.