No Crank Issue

[Steve Fowler]

Recently acquired a 91 Reatta. Drove it home 100 miles with multiple stops with no problems. After arriving home, went to move it. Won't crank. I'm an experienced tech and have access to Mitchell On-Demand. Battery is okay, starter spins when jumped Bat to Solenoid. Have removed panels below steering column. Disconnected wires from PASS key part of ign switch and tested resistance with key in- matches reading on key and coincides with a #9 value. Checked all fuses in panel alongside drivers leg, all okay. Tried wiggling shifter and using Park and Neutral positions- no joy. Suspect problem is in VATS module or starter relay, which supposedly are just above the park brake assy, but have not been able to spot them. Any help would be appreciated.

[2seater]

I had an 89 that developed a similar condition out of the blue also and it turned out to be the plug at the neutral safety switch on the transaxle had become corroded and green. Cleanup and contact cleaner cured the problem and has not returned in 18 months.

[Ronnie]

8 hours ago, Steve Fowler said:

Suspect problem is in VATS module or starter relay,

Below is a diagram that shows the flow of power to make the starter run. You can use that to trace down the problem. The other diagram shows how you can bypass the starter interrupt relay as a test to see if the VATS is the problem. I would try what 2seater said first.

 

[Padgett]

I'd probably short the power output on the starter interrupt relay. The red line seems to be without the VATS (theft deterrent).

Edited August 29, 2022 by Padgett

[Steve Fowler]

Thanks for all the input. I bought a factory shop manual, much more detail than Mitchell On-Demand. Finally found the bracket that carries the VATS module, the relay and the security module. Had to pull the driver seat and poke my head way back in there to find it. It is tucked up nearly at the firewall next to the park brake mechanism. Per the shop manual, I jumpered past the relay but noticed that when I energized the circuit, the 14 ga jumper got real warm. Ultimately, it took out the fuse link protecting the circuit. I figured there had to be a short circuit, and by disconnecting the neutral safety switch, then the 50+ pin connector under the right side of the dash I was able to isolate it to a short to ground in the wire leading from the big connector to the neutral safety switch. A careful examination of the wires found a rub-through at the left front of the core support where the convolute tubing had disintegrated over time and let it rub on a bracket. Some fresh convolute tubing fixed the issue. A real head scratcher, but not the worst that I saw in 37 years as a college auto tech instructor. I'm sure I will be very glad going forward that I found and bought a factory manual. I always prized the library of info I had available while I was teaching.

[DAVES89]

Wow! That was pretty good. I think I'll be moving to central Arizona...

[Ronnie]

Glad to hear you found it, and thanks for sharing what it took to fix your problem.

[Padgett]

Triage is good.