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pbdevastator
08-15-2015, 07:33 PM
This is an auto AOD. When I hold the brake pedal down then try to start the car, nothing happens. So the steps taken thus far is we have bypassed the starter solenoid and had a volt meter attached to battery. When we bypass it does crank and the voltage on battery is around 12.5. But the car still didn't start which could be another issue on its own. At this point though I am thinking either the ignition switch or solenoid might be bad. But what else would have prevented the car from starting when we bypassed all that? Any help or simple steps would be helpful before I assume or do anything more major then what we have done.

Also There was a good amount attached to that solenoid, which wire is from the ignition switch?

KMT
08-15-2015, 07:43 PM
Did you check the multi-wire ignition switch down on the right side of the steering column (not the lock cylinder) - when they get old they have a habit of coming apart and creating various issues, so I'd start there. Not that expensive and usually easy enough to find new.

Otherwise, work the test chart here: http://mnharms.com/tutorials/disnostart/

90tbird4.7l
08-15-2015, 09:04 PM
does it start in neutral?

shoalcracker
08-15-2015, 09:13 PM
Confirm you have brake lights.

Paul

pbdevastator
08-15-2015, 09:19 PM
Yes I made sure brake lights work. And yes got the car started. Totally forgot to reconnect the msd box when putting things back together. Not sure if other SCs are like mine, but I have to hold brake down otherwise car wont even try to do anything when trying to start it. So I know starter is good. So could be ignition switch. Maybe that sensor for the brake is messed up and that is my problem. Could it still be the solenoid? Last thing is not sure which wire is from the ignition switch. I could eliminate that if i knew what wire it was for sure.

90tbird4.7l
08-15-2015, 09:33 PM
could be your neutral safety switch, sometimes you can lose all starting (both Park and Neutral) or just in Park. All 1990 thunderbirds and cougars, you have to press the brake to start (was a one year feature that not many liked)

KMT
08-15-2015, 10:23 PM
It looks like BLK/ORG out of the switch & thru the power dist box.

Don't forget to check all wires big/small at the starter.

S_Mazza
08-16-2015, 12:25 AM
I think you are on the right track. I would bet it's the ignition switch going flaky, as KMT said. I assume this is a 1990 because of the brake pedal interlock. That being the case, the starting circuit does involve the brake light switch and a relay under the dash. But check for power at the solenoid on the fender first. If none, check the ignition switch on the column. Other causes are rare. Ignition switch is almost guaranteed to need multiple replacements over the life of the car.

shoalcracker
08-16-2015, 10:17 AM
I just went thru this.

If you run your hand down the underside of the column you can feel the main harness.

I was able to push up on it and close the loose ignition switch.

It was a quick check to confirm switch had separated and the only way to start the car.

Paul