I installed the Rallye pac gages in my car last year. When the car starts the temp gage pegs then works normally after start up. I know there's an easy fix for this (something like truncating the idiot light test lead) but I can't find that information on any searches here. My eyes aren't the best either so looking in the CSM for the electrical diagram hasn't given me what I'm searching for either. Anyone?

 

You need to disconnect the dark green wire from the ignition switch. There is a “bulb test” position in the ignition key rotation, just before crank, and right after the run position. The bulb test position provides a ground to the warming lamps. Since you now have gauges, when the bulb test grounds the green wire, it causes the gauge to go full hot.

 

But isn't that like the new thing in cars? I think I've seen all needles, including tach and speedo, go BANG full right, then back to normal in new cars.

 

Thank you. I had a funny feeling it was the dark green wire but wasn't sure. And yes, that's exactly what happens - pinned to full hot till car starts, then it's normal. When I looked at the electrical diagram I didn't read where it split to go to the ignition switch. You've made my job a lot easier. Getting the ignition switch wire out should be pretty easy once I drop the steering column.

No it's not supposed to pin like that. I don't know what effect it has on the gage if it would continue to pin but I'm making the change required for the U21 package. Funny there were no instructions that mentioned this. As to new cars? I guess it depends on the manufacturer. My new Sonata does a 'System Check', much like other cars and trucks of the modern era. Makes me feel like I'm on the starship Enterprise at times with all the doo dads and gadgets to play with.

 

Item #6

https://www.thepartsplaceinc.com/dat...stallation.pdf

 

Thanks Pat. I don't have a reproduction unit - it's OEM. I got the green wire out of the harness and taped it off. Gage works perfectly now.

 

I think that part of the procedure works for either the repro or the OEM. (modifying an idiot light harness to a gauge harness), right?

 

Not all of it. Just the oil pressure. Everything else was basic configuration as outlined in the CSM. After disconnecting the green wire at the ignition switch it works just fine. I did have to buy new senders for the conversion from idiot lights to gages, but I knew that in advance.
Whether OEM or repro, you're right the conversion is the same. Only thing different is mine is OEM and the repro has issues with lighting, which can be corrected with work.

 

Allen I had the same problem. If the problem is the green wire like everybody points to then you are good to go. If it's not,it just might be the little wire coil in the gauge, It may have shorted out like mine did. The shop I take my cars found that and ordered new coils for the Gauge and now works fine. Good Luck

 

That green wire is the "check circuit" for the oil pressure idiot light. When you start the car with idiot lights, the "oil" light comes on for a few seconds before it goes off. When converting to gauges and not disconnecting that green wire, that's what pegs the oil pressure gauge for a few seconds before it returns to normal. I had to do the same thing with my '68 when I converted from idiot lights to gauges.

Randy C.