[southside39]

Having issues getting the 75 Grand Prix to start... again.

Last time it was a timing issue but this time it's something else. I turn the key and get nothing, it does not crank or make any noise. Also it ran and started fine when I parked it last year due to some suspension issues.

So I started simple and replaced both the battery and starter. The battery was not holding a charge for long and the starter was all fouled out with oil. I tried to start it after this and got nothing again.

However, when I jump the terminals on the starter solenoid the starter does engage and turn the engine over. So this seems to be a wiring issue especially since my wiring harness is not in the best of shape.

I was hoping that before I bite the bullet and buy a new harness I could get some recommendations on where to look/test for voltage to see where the circuit is broken. Thanks for any help.

[Blued and Painted]

Is it a floor shift automatic? If so the shift collar on the columb may not be in the park position. It connects to the neutral safety switch. Grab the collar below the blinker lever and twist counter clock wise then re-test.

[southside39]

It is a floor shift automatic. I have had problems with the tab on the engine side of the steering column that releases the keys, is this what you are talking about?

[Blued and Painted]

Yes, Its connect to the neutral safety under dash. Other problems could exist but i would start there.

[southside39]

I made sure it was in the right position and tried to start it but no luck. All I got was the buzzer sounding, same as before.What should I try next?

[Greg Reid]

Does anything happen when you turn the key? Dash lights go dim, headlights go dim, etc.?

[stellar]

Are the wires on the correct solenoid posts, and all the wires connected at the solenoid?

[southside39]

Dash lights don't go dim. All I get is a buzzer sounding when I turn the key. There were two wires to the solenoid and they are both hooked up to the correct posts.

[Greg Reid]

That indicates to me that nothing is being routed past the ignition switch or neutral safety switch.
In fact, that buzzer shouldn't even be sounding once you turn the key. Indicates that it still 'thinks' it's in the off position.
I'd take a closer look at what Blued and Painted mentioned and after that start checking the ignition switch itself, neutral safety switch, etc.
Can't help you much there as I've never had to tear a column switch ignition apart.

[southside39]

How would I go about checking the ignition switch and neutral safety switch?

[TedRamAirII]

Follow the big Purple wire. It should have power at the ignition switch (in the crank position) if it does, then verify it at the bulkhead connector, firewall side. I assume lights, horn, operate normally?

[southside39]

The horn hasn't worked since I bought the car, it has an aftermarket grant wheel so not sure if that has something to do with it. But the lights work like they should.

[TedRamAirII]

I tried looking at a diagram, but it got me even more confused. power went from ignition switch, to neutral switch but then didnt end up at the bulkhead connector? But then came out of bulkhead connector to the starter.Also had a seat belt switch wire coming out of the neutral switch but wasnt on the diagram i had. the diagram was not complete, so who knows. I think the power wire at the ignition switch was red.The wire you will need to look at should be Purple from Ignition switch to neutral switch all the way to the "s" terminal on the starter. Just going on memory. ; )

[GOLDOHC]

I had a 73 Cutlass that had a relay under the hood, the seatbelts had to be hooked up to activate the relay or else there was a buzzing noise. As I recall the relay was on the firewall by the brake booster. That was 36 years ago.

[Greg Reid]

Forgot about this thread....Mentioning the seatbelt switch reminded me that on the '74 Trans Am/Firebird, there was a seatbelt switch that went to a relay on the driver's side inner fender. If that thing goes bad, you definitely will not engage the starter.
You can see it on the inner fender on the pic below...right ahead of the master cylinder.
Does your '75 GP have anything like that?

[TedRamAirII]

Originally Posted by Greg Reid

Forgot about this thread....Mentioning the seatbelt switch reminded me that on the '74 Trans Am/Firebird, there was a seatbelt switch that went to a relay on the driver's side inner fender. If that thing goes bad, you definitely will not engage the starter.
You can see it on the inner fender on the pic below...right ahead of the master cylinder.
Does your '75 GP have anything like that?

Is there a purple wire on the relay? is there is, you should be able to bypass it or put
12V on it and the engine should crank. ; )

[Greg Reid]

That's right. If I recall correctly, you can actually unplug the relay and place a jumper on the relay base/socket connecting the two points where the purple wires attach.

[southside39]

I'll check to see if I have that relay for the seatbelts this weekend when I get done with work. Maybe that's what the buzzer sound is coming from as I have attempted to start it without a seatbelt on because it's sitting in my garage. From what I've read online the seatbelt switch was on 74s and early 75s. My grand prix is an early 75 (it has a 481988 block) so mine might have the switch. I'll update tomorrow

[southside39]

There was no relay for the seatbelt. I was able to get it started after some rewiring of the starter. Thanks for all the help figuring out what was wrong.

[stellar]

What needed rewired on the starter? Was a wire missing or was one in the wrong place? If you did it someone else probably has or will in the future. Your input may help the next person.