Grounding Out Issue yet engine sometimes stays running

[Darwin686]

So I've had a fun couple of days trying to figure out what is going on with my 1991 Camry.

Symptom: When driving for a short period of time I hit the breaks, doesn't matter if soft or hard braking, and all dash lights and everything grounds out, sometimes the engine will stay running if i release or it will stall softly, straight shutdown with no sputter. Other times the engine will stay running however everything else resets: computer, clock, seat belt warning, radio, ect. Its really odd when the engine stays running and everything else seems to drop like a ton of bricks and comes right back up. There have been no blown fuses or circuit breakers.

Well first thing that came to mind is the brake light switch. I have changed that out without taking my front dash apart, an acrobatic feat, and will be testing that today to see if the problem persist.

Has anyone else experienced this? I have gone through and checked all wire connections in the engine compartments, tested, battery and alternator, both pass, ignition coil was recently changed out.

IF the problem persist I'm going to dismantle the dash and look for frayed wires. To me this is a bit strange however I assume it could just be a faulty switch, after it is is original and I've over 300k miles on the vehicle.

If anyone has any advice I would love to hear, my concern now is if the car is grounding out the potential for vehicle fire is eminent.

Thanks Guys and Gals.

[Doctor J]

You may want to remove a stop fuse and attempt to start the engine. if it will not start and dash warning will be out after fuse removal the power feed to the ignition and main relay may have problems (from the symptoms you desctribed the ignition system is getting power from the break light feed)

[Darwin686]

Doctor J,
Thank you so much for your response. The brake light switch had no effect. I will certainly give your idea a try tomorrow, presuming it stops raining here. Where would you recommend I go from here?

[Doctor J]

you may want to remove the light failure sensor and see if it cures the problem
If yes,connect green/wht to green/red wires (to enable stop lights) and repeat the test if problem persists check the light bulbs

[Darwin686]

Doctor J,
Thank you so much for the response. I'm bout to go get started on everything. I did want to run this by you. In doing some research and seeing how the ignition switch wiring harness is with this car. Other than the brake light failure box being a problem, do you think it is possible that this harness is failing? It the original with the car.

Also new event that I want to share with you. Twice yesterday when I came to a park position and removed the key everything seems to be shorted out. Seat belts would not function, instrument panel lights were barely illuminated, no interior dome lite. It wasn't until I put the key back in and went to the ACC that everything came back up and when I removed the key again it was fine. At this time the brake was not depressed.

[Doctor J]

I am thinking also about the transmission shift interlock system circuit when brake is depressed it energizes solenoids which lettting you to shift; also some cars (88 V6 le) had a feature that does not let you to lock the door when key is in ignition. these places I would look next

[sam333]

I have had this happen( engine quit , dash lights go out ,but mine would also quit when the blower or rear defrost was turned on in addition to the brakes.

It was a bad connection were the positive battery cable went into the fuse block.

It was on again off again, and a pain in the butt. I Had checked all connections under the hood ( grounds and power) but not well enough.

I found where the problem was by starting the car and turning on my blower and headlights, then used a multimeter on DC volts ( lowest setting) to check for voltage between the plus side of the battery post and the plus side at various points in the circuit( I was looking for voltage over 0.2 volts). A voltage reading over 0.2 volts indicates high resistance in that part of the circuit. Found it in the fuse block. One of the hot wires coming in was corroded( black) inside the insulation. I cut the corroded part out/ put in a new piece and no more funky electrics.

[Darwin686]

Well today when i got home I jumped on the old Toyota and have not located the problem as of yet. I guess I should explain. I went looking for a brake light failure sensor. As fate would have it, it does NOT exist in my 1991 Base model Camry or it is is some really, funky position.

Tonight I took the seats out, took out all the trim panels, and undid the wire looms from the right brake light up to the drivers seat, PS that is A LOT of trim and carpet to remove.

I still have yet to find the problem.

Dr. J I tried your test with the fuse pull and had no luck. SO the plan tomorrow.

I'm going to finish putting the trunk back together and then move onto under the hood. I haven't seen any wire corrosion yet but I wouldn't be surprised in the slightest if that is the problem.

Hopefully tomorrow will be the day

Forgot to mention.. Last night I was getting coffee durring a downpour and came out the car and started right up pulled out of the parking lot into the turn lane and hit the brake. At this time the car simply shut off. Not even emergency flashers would come on. I sat there for about 2 minutes and the car came back to life and cranked back up. This ground out is driving me nuts!

[Darwin686]

Well today I started ripping out everything under the hood of the car looking for shorts and problem and doing a double check of all systems. I found two things today that were interesting and needed to be addressed.

Two f usable links were failing. One for the 80AMP Alternator and the other for something else.

Not realzing that the fuseable link on the alternator is bolted in place i tried ripping it out with pliers. Needless to say it broke into a million little pieces. At this point I discovered that although the top of the fuzable link was fine there was major corosion on the inside of the fuze. I guess that would explain why there was some funky resistant readings from it. So that was replaced

In the fuse box under the hood was another fuseable link, 30AMP, with corrosion inside the fuse, so that was replaced. I took that entire assembly apart and cleaned it with electric parts cleaner to get all of the old ass road crud off of it. NO shorts or signs of corrosion on the wires.

Took the battery and alternator out and went to autozone and advance auto parts and they tested fine in both locations.

Came home and put everything back together.

Here is where it gets intresting. Took the car for a test drive and the lights are hardly dimming at all now. However coming from the front drivers side kick panel, aka tomorrows project, I am hearing a clicking like either a relay, circuit breaker and/or self resetting circuit breaker clicking away when i hit the brakes and left off the brakes!

I think I have finally found the culprit! So tomorrow the pan is to come home and take out the lower dash panel and see if I can get the problem to occur while in park with the engine running to determine just which electrical item it is that is causing the problem.

Hopefully tomorrow I will be able to share just what went wrong with my camry.

Cheers Fellas.

[sam333]

Interesting, good info. Waiting to hear what you find.

Most electrical problems are a combination of system failures, and makes them hard to trouble shoot.
It helps to have a " Restoring it one bolt at a time..." attitude .

[white90dx]

The tail light failure sensor is located near the fuel filler - It is clipped on the back side of the sheet metal that is there between the back side of the fuel filler at the trunk. You DO have one, or it was removed by a previous owner. If it has been removed, you will find a lot of wire splices, as the tail lights won't turn on without it. You only have to remove one piece of trim to get to it.

-Charlie

[holmesnmanny]

Take the battery off and see if the terminals are corroded, both on the battery, and on the connectors. What could be happening is that the battery jiggles while driving and it doesn't make a good connection so it doesnt' get charged, then you hit a bump and it makes a connection again. If anything, just pick up a wire brush battery cleaner for 4 bucks and scrape all of the connections again and see if that works.

This more or less happened to me, I thought because the connections were tight it was fine but it turned out the connections were corroded to the point that it was essentially insulating the connections so they wouldn't make good contact sometimes. It didn't even look corroded.

[Darwin686]

I think i found the culprit. A bad self resetting circuit breaker. I replaced it yesterday and NO failures! So far. I'm going to do testing over the course of the weekend to see if it does exist.


"white90dx The tail light failure sensor is located near the fuel filler - It is clipped on the back side of the sheet metal that is there between the back side of the fuel filler at the trunk. You DO have one, or it was removed by a previous owner. If it has been removed, you will find a lot of wire splices, as the tail lights won't turn on without it. You only have to remove one piece of trim to get to it.

-Charlie"

Hey Charlie glad to hear from you. I actually confirmed it with my local toyota dealer that my base model did not come with a brake like failure sensor. Its really cool what they can look up on your car with the VIN number. There apparently only a few out there that do not have it and lucky me I do not have it. When my grandfather bought the car he go it as basic as possible. He wouldn't have the slightest clue where to even begin to look for such a device if it did have one. Also my fuel filter is under the hood by the drivers side tire :P


Next response

"holmesnmanny Take the battery off and see if the terminals are corroded, both on the battery, and on the connectors. What could be happening is that the battery jiggles while driving and it doesn't make a good connection so it doesn't' get charged, then you hit a bump and it makes a connection again. If anything, just pick up a wire brush battery cleaner for 4 bucks and scrape all of the connections again and see if that works.

This more or less happened to me, I thought because the connections were tight it was fine but it turned out the connections were corroded to the point that it was essentially insulating the connections so they wouldn't make good contact sometimes. It didn't even look corroded. "


When took all of the main engine parts out I did clean all contacts on the car from the fuse box, to the battery, to the alternator and all dielectric grease was redone as well.