Cutting off...

[magindat]

I've solved the car cutting off problem.

I remember we had a friend in Hawaii sell because of this. We guessed all kinds of things from alternator to bad ground.

Symptom:
Car cuts off unexpectedly while driving.
> Speedo goes nuts
> Dash lights blink on and off
> engine stops
> unpredictable - unexpected
> seems to happen more when weather is hot and car is hot

You won't believe how simple it is.

Relay 202 in the Power Distribution Box.

I had been having very similar troubles as our Hawaiian friend (forgot screen name and can't find thread) who finally sold his car out of frustration over this issue.

I pulled fuses and relays and studied the wiring guide until I duplicated the problem.

Finally, once isolated I swapped 201 (horn relay) for 202 (PCM relay) since the horn relay see next to 0 usage in comparison.

It seems the PCM relay coil wears out. Most relay will at some point. The hot underhood temperatures made it even harder for the coil to stay closed. At first I noticed it would cut off when the alternator 'kicked on'. This very momentary drop in voltage would let the coil inside the relay go.

This is a simple fix after complicated troubleshooting. I just wish it would have happened to me before he sold his car.....

[magindat]

It was kamikaze2899 with this and other problems - but may have been related

also BLK3 had this issue with a CV.

[Local Boy]

Thanks Rich...

I just copied, and will save your post in my Tech. Book at home...for future use...

ALOHA

[O's Fan Rich]

I've solved the car cutting off problem.

I remember we had a friend in Hawaii sell because of this. We guessed all kinds of things from alternator to bad ground.

Symptom:
Car cuts off unexpectedly while driving.
> Speedo goes nuts
> Dash lights blink on and off
> engine stops
> unpredictable - unexpected
> seems to happen more when weather is hot and car is hot

You won't believe how simple it is.

Relay 202 in the Power Distribution Box.

I had been having very similar troubles as our Hawaiian friend (forgot screen name and can't find thread) who finally sold his car out of frustration over this issue.

I pulled fuses and relays and studied the wiring guide until I duplicated the problem.

Finally, once isolated I swapped 201 (horn relay) for 202 (PCM relay) since the horn relay see next to 0 usage in comparison.

It seems the PCM relay coil wears out. Most relay will at some point. The hot underhood temperatures made it even harder for the coil to stay closed. At first I noticed it would cut off when the alternator 'kicked on'. This very momentary drop in voltage would let the coil inside the relay go.

This is a simple fix after complicated troubleshooting. I just wish it would have happened to me before he sold his car.....

I'd tell you, "you're the Man" but you already know that!

[Black_Noise]

sounds like work.... Good info

[TooManyFords]

Rich, just FYI, I read your post and ran (literally) to the garage to test this. You see, my car has been doing this since late June, the dash would act crazy and the computer would reboot sending the transmission into a tizzy searching for a gear.

Well, I swapped the two relays and unfortunately it still does it. Tomorrow, the car goes in to have the TH400 put in so I guess I will always wonder what caused the problem.

Cheers!

John

[03blackvegas]

Turbo 400?, why not a 727B?, or wait a minute, a C6. Forget it I'am just rambling.

[Jeremy]

I had this happen to me once, scared the crap out of me because I was into the car pretty hard.. good info.. thanks!

[magindat]

Rich, just FYI, I read your post and ran (literally) to the garage to test this. You see, my car has been doing this since late June, the dash would act crazy and the computer would reboot sending the transmission into a tizzy searching for a gear.

Well, I swapped the two relays and unfortunately it still does it. Tomorrow, the car goes in to have the TH400 put in so I guess I will always wonder what caused the problem.

Cheers!

John

The tranny would go nuts, too if it quit at highway speeds....

Sorry this didn't help, John.