Hey all,
73 Cutlass S
Did the gauge install and it went well following all the instructions on here. The issue is that in the start mode, the temp gauge pegs out and in the run position it is fine. With the engine running, all gauges and lights work as they should. Just the temp gauge pegged out as long as the engine is cranking. Is that normal? I read in a post that the green wire on the steering column harness needed to be unplugged or the gauge would peg out in the run position, which I did.


thanks for your thoughts


Marc

 

Sounds like the feature prove the HOT lite during cranking is still hooked up. Distach its wire at ign switch or dash to fix that.

 

There should be a green wire in the harness that comes down inside the steering column from the turn signal/ignition assembly. There is usually a bracket where the harness emerges from the steering column, just under the dash, and the plastic harness end is hung on that bracket. If you simply disconnect the green wire from the harness and tape it off, that should solve the pegging problem. All of my GM cars have run from the '68 model year to the '72 model year and that's what I did in every case (for '68 it was the green wire from the backside of the ignition on the dash) when I converted from idiot lights to gauges.


You should be able to back the green wire out of the plastic harness without cutting it. There is a metal tab that holds the wire in the harness that you should be able to see if you shine a light into it. With a very small screwdriver, you should be able to push down the tab and back the wire out of the harness.


I've heard a couple of theories on if the pegging is harmful or not to the gauge. One theory was that, with continued pegging, it will eventually damage the gauge. The other theory I've heard is that the pegging won't have any ill effects on the gauge at all.


A car that came from the factory with gauges didn't have the pegging problem. I personally like to keep it that way so that's why I disconnected the green wire in the conversions I did.


Randy C.

 

Hey Octania,
Any idea where that wire is? Is it from the original idiot light harness that I re wired?




Hey rcorigan 5,
I found a green wire on the steering column that I pulled out of the plug. Is there another one I should be looking for?


Maybe I have the wrong green wire????




Thanks,
Marc

 

I just went and looked. There is only 1 green wire coming down the steering column. Could it be another color on 73's?


Marc

 

That's the only solution I know. I'm wondering if the color of the wires changed between '72 and '73 model years. Sometimes there is a light green wire and a darker green wire...the darker green wire would be the one to pull.


The reason the gauge pegs is because of the "check circuit" for idiot lights. When you put the ignition in the "run" position with idiot lights just before you start the car, the "temp" light comes on. And when you start the car, the light goes off. What's pegging the gauge is that "check circuit" just before you start the car as the "check circuit" disengages after the car starts.


I would suggest looking at the electrical chapter in the chassis service manual for your year. You should be able to find that "check circuit" and it will identify the color of the wire for that circuit.


Randy C.

 

Hey Randy,
Good idea but I don't have one. Does anyone on here have access to that info for me?


I will do some searching too on my own to see what I can find.


Marc

 

OK all you wiring dudes,
I found a diagram for a 73 cutlass and it does show a dk green wire for the temp that is hot in the run, bulb test and start modes. I have unhooked the dk green from the harness under the dash at the steering column. I have the temp gauge pegged at the start mode. It also shows a dk blue/ dk blue with wht that is the oil pressure switch. Does that also have a test bulb with the idiot lights that may peg the temp switch? I could always just try it and see what happens when I disconnect the dk blue one. I am hoping some one else had this issue and offers a solution.


Marc

 

The only test circuit that I know of has to do with the temp gauge for idiot lights. I've never had to do anything with the oil pressure input.


BTW, thank you for your service! You deployed to some pretty interesting places. My service life wasn't nearly so "exciting"!


Randy C.

 

Hey Randy,
You are welcome. Yea, I have been to some "interesting" places.


I am totally confused now. I took the wires off the flat connecter from the steering column one at a time and they all made other things not work like turn signals and the flasher. I still get the Gen idiot light tho at the bottom of the rally gauge, no matter what wire I have unplugged.
With the green wire off, like most of the posts on other threads say to do, everything works except the right turn signal and the temp gauge pegs while in the start mode!!


There is another green wire under there but it is not with the group coming down the steering column. There is a more boxy plug farther up near the top of the column that has 3 wires from it and 1 is green. I can't figure out how to get it out to pull the green one tho.


I obviously need some one that has done this on a 73.


Any takers?


Thanks,
Marc

 

I wish I could help you on this one but I am stumped as well. Somehow, you've got to be able to locate the temp check circuit and disable it, but where and how is apparently somewhat different than the '68-'72 model years. Hopefully, someone with '73 experience in swapping idiot lights for gauges can chime in.


Randy C.

 

Hey Randy,
Yea, you are right.
I will start another thread and be more specific about what I need right up front.
Thanks for your thoughts on this
Marc

 

Hey all,
I have done the install of the gauge and it works great. I have the issue of pegging the temp gauge during the start mode. I need help identifying the temp test wire from the idiot light set up so I can disconnect it.
I have read all the posts on this forum and on the 73-77 forum.
I have looked on the internet for the wiring diagram but none I have found show the test circuit.
I have been a registered member on the 73-77 forum since May 9th but as yet cannot visit as a member or post a question since it still shows all the areas as private. I have asked to be let in and have heard nothing.
The wiring is different than 68-72 as I have tried the green wire under the steering column and that is the right turn signal. I have tried all the colors under there and they are all other things besides the test circuit.
I am hoping that someone can help solve this for me.
Marc

 

OK everyone who has been interested in this, rcorrigan5 had the answer. It is NOT the green wire coming from the steering column. It is the green wire that is on top of the column. There is a black and a white plug, side by side, on top of the column and it is the green wire in the black connector. You will have to lower the steering column to get enough room and then hope you have small girlie hands like me to get in there to release the clips that hold the plug in place. Then it is easy to release the clip that holds the green wire in place, tape the male end off and re-assemble.
Works like it should
Thanks to all who helped work through this, especially rcorrigan5


Marc

 

I combined your 2 threads for the history. Glad you got it fixed.

 

Thanks oldcutlass for doing that. It may help someone down the road.
Marc