Hello, I just got my Vic back together recently. Yesterday I took it to the exhaust shop and when they were done they said it wouldn't start. So I went to give it a go and nothing. Now today I took all my tools over there and tested the battery, tested good on the load tester. Found the starter relay, swapped it for the A/C shutoff relay, no difference. So then I jacked it up and pulled the starter, threw it on a charger and jumped it, bendix worked fine, brush jumped out and spun real good (it's a brand new starter, but you never know..)The only things I think that are left are the ignition switch and the neutral safety switch. I finally got the car home by jumping the starter. I don't get it though, it started perfect before the exhaust shop and now it won't do anything when I turn the key. I checked the shifter too, by the way, jiggling it so see if the cable was misaligning the gears slightly.

Any ideas, tips, tricks?

Find the 30 and 87 terminals in the fuse block for the starter relay. The numbers should be shown on the bottom of the relay. Put a jumper wire into the 30 and 87 terminals in the fuse block and see if the starter cranks the engine. If the engine cranks, you can rule out the power to the solenoid as the problem. That means you're chasing a control circuit fault. That could mean the ignition switch, the transmission range sensor, any of the wiring in between, or whatever else I'm not thinking of if you get this far.

I take it you checked the fuel shut off switch? How about PCM diode? Check all the fuses too.

I bet those dummies at the exhaust shop were welding and blew something out.

I haven't checked the fuel shut off yet, but could it have been set off from that anyways? All he did was throw it up on the lift and weld, it's a pretty reputable guy that's been doing this for years. How do I check the PCM diode? I jumped those terminals and it cranked over. I checked a couple fuses in the engine bay, and they're all good. I'm going out of town for a few days so I'll see if I can find something when I get back next week.

When I had a muffler installed on my 89 Cougar after they got done welding...my gas gauge was never the same. It always read correct before, but after the muffler it nearly always read full.

Did you have more than mufflers done, like anything near the transmission? I would try more than wiggling the shifter, try in neutral and up and down from neutral.

This is highly feasible. If they left the battery connected in car while welding, they gave the welder an opportunity to fry components & wiring in the car. The welder is pushing significantly more voltage than the 12 volts the battery offers. That voltage is going to push a lot more amperage and can conduct electricity in circuits of the car regardless of whether the key is on or not.

Ok a new update on the car, about 2 weeks ago I was driving at night and with the headlights on, the battery drained. So I got a jump from my girlfriends dad, started it, pulled off the battery cables, died instantly. Ok, went to get the alternator rebuilt by a guy who knows his stuff, he tested it, it's fine. He said to check the key on power wire going to the regulator, but then I told him how the ignition key won't start the car.(By the way I installed a push button to jump the starter) and he said it could be the fusible link. So where would I find this fusible link, probably under the dash? Is there one that involves both charging and starting?

Went to the dealership and got a print out of the charging system schematic. There's two fusible links after the battery, one positive wire goes off to the starter motor, the other goes into the fusible links, into the fuse box, into the alternator and tees off several times. If anyone replies back I will post up this schematic so it will be public access for the crown vic community. For an 02.

The fusible link is inside the Alternator to battery cable. It protects the battery from an overload from the alternator (i.e. a fire). The car would still start even if these were fried - they have nothing to do with starting the car.

I will reiterate what others have said above - they probably screwed something up welding. If it started and ran fine when I took it in, and it didn't coming out, I'd tell them you fix it. I've had the dealership damage stuff on my car, and just hand it back to me like nothing every happened.



Pulled which cables off? The jump cables or your battery cable?
If it was your battery cable, DONT EVER DO THAT AGAIN!!! That will fry an alternator faster than an egg.

Yeah we pulled off the battery cables. We do that all the time on tractors and whatnot to see if the alternator is bad, never had a problem from it. I've never heard of it frying an alternator.

Yeah I mean it had to be the shop that did it. I'm going to put an inline fuse in place of the fusible link today and hopefully this will be the end of my charging woes. And I think this might be the culprit for the starter too because its all upstream of the ignition wiring, according to this diagram. The main line tees off before the fusible link, but all the starter wiring involved with the ignition key is after these fusible links, so. We will see. Thank you for everybody's input.

Nothing wrong with pulling the batt. cables off with the vehicle running, provided the charge cable is crimped or remains connected to the pos. (+) distribution cable. The vehicle will continue to run for several minutes as long as the current has somewhere to go. Good techs will actually change batteries this way without having to invest in a battery saver or reset lost memory.

The batteries two main functions are for starting, and energy storage. It's just a reservoir for electricity. The alternator powers the car while running, with or without the battery. If for some reason the charge cable comes off separate from the distribution cable, then it's not advisable as damage or arcing may occur. Other than that, the only other instance I'm aware of that it doesn't work is on Lexuses for some reason or another.

The battery is also a buffer/sink, and maybe a 70s era and maybe 80 era car can handle that, but there are so many things to fry in a new car when you pull the battery. A good way to lessen the life of the alternator, and all electronics in the car.

Oh I gotcha, thanks for letting me know. I've started a new thread solely for this charging problem, named charging issues.

We both told ya. Now you know. :-)

Had this exact problem the other day after car sat for mouths and was happy to find this thread.... However disappointed there is no solution that the op has posted (other than bi-passing the starter today) anyways i have solved my issue.
It was the 5a transmission selector fuse. Replaced and started right up