cor66vette

I have nothing out of the IGN cavity of the fuse panel. This I found out while trouble shooting the PW circuit, since part of the PW relay needs the IGN cavity.

What would cause this and what is the best method to check the problem?

Thanks.

mysixtynine

I have a 69 wiring diagram so I dont know how close this is to your car.

But the IGN contact in the fuse panel appears to come from the Pink with black tracer wire coming out of the ignition switch on the steering column so you have an ignition switch issue or that pink black wire is bad.

My ignition switch connector is white and the wire starts out pink then got to pink /balck

Of course this is if your 75 is the same as my 69.

DUB

If my memory serves me correctly. The IGN terminal in your fuse panel has to have a good fuse beside it to make it "hot" when the key is on. On one side of your fuse panel are the fuses that are "hot" without the key being on....such as brake lights, courtesy-clock. The other side of your fuse panel are those circuits that become "hot" when the key is on...such as wipers. SO...the fuse that is beside that IGN terminal needs to be a good fuse to make it become hot... because GM wants that terminal fused...so when you plug a connector into it...it is protected.

DUB

loup68

Doesn't the PW plug in the ACC spade right above the IGN spade? It does on my 68. Lou.

cor66vette

Visually, the fuse looked okay. I'll double check in the morning and test it for sure. Thanks.

Thanks. I have one lead from a headlight warning buzzer connected to the LPS cavity, and the other buzzer lead connected to the IGN cavity, and the latter lead is pig tailed which in turn feeds 1/2 of the PW relay.

Peterbuilt

So, is the fuse good?
They can look good but you should remove them, check that the ends are good and that you have continuity.
77 diagram:

cor66vette

My intention is not to trust what I thought I saw as a good fuse in the fuse panel so the continuity test is a decision maker of sorts. The rain was unrelenting today so I wasn't able to test it. I know, I know- the car in the driveway? I'm arranging the purchase of a garage lift as we speak. Something had to be done with 3 cars and a two car garage. Thanks.

DUB

OK...I looked at my wiring diagram and I was correct. The IGN terminal in the fuse panel is fused.

Power feed to all of the fuses are coming in at the outer ends of each bank of fuses. The current flow goes INWARD from both ends...through the fuses ...and then to the appropriate circuits. This includes the BAT, IGN and ACC terminals. These are all fused.

I have been "bit" before cor66vette in issues like this. DO NOT BE FOOLED BY A GOOD FUSE!!!! If your fuse is good...GREAT!!! But the problem can and is more likely occurring in where the fuse is making contact to the terminals that secure the fuse in place. I have had many cars where the power coming into the fuse panel ( with no fuse in place ) is 12 volts. And when I install the fuse and power up the circuit...the TERMINAL on the other side of the fuse is 7 volts. This is due to corrosion or some "stuff" not allowing the fuse to make good contact. SO use a volt meter and NOT a continuity tester.

DUB

cor66vette

From what you're saying, the IGN is powered (fused) by the 20a tail light fuse?

cor66vette

Dub,
I stand corrected. So the feed comes from the fuse to the right, the 10A gauges fuse?

Pete,
Thanks for the heads up, and the diagram. This is all starting to make sense with the help from you guys.

cor66vette

*** === UPDATE === ***

The 10A gauges fuse was blown. It looked good in the fuse panel, and believe it or not, it looked good in my hand. It failed the continuity test.
I now have power in IGN.

Thanks to all the guys who helped me out with this IGN problem, especially Loup68, mysixtynine, and special thanks to petes74ttop, and DUB.

I appreciate your time and effort.

DUB

Yes you are correct...the gauges fuse ...in your illustrations of the fuse panel in posts #9 and #10. The power coming into the fuse panel are on the far left and far right sides....where the amp ratings of the circuits are printed.

INST LPS gets its power from the headlight switch being pulled....via the dark green wire on the headlight switch.

DUB