Electrical gremlins.. looking for a place to start troubleshooting

[Superflo]

Hey all,
So this happened to me last night. Looking for suggestions on where to start to look. Note that it has been raining heavily (for southern california) the past couple days.

I'm driving on the freeway when the AT Temp light and Brake light slowly light up, then go away, then light up. I figure it's a weird combination of lights and can't be a real transmission issue. About a mile down the road she starts bucking slightly, so I decide to get off the freeway. I take an exit and limp into a gas station, car died right as i was pulling in so I coasted right into a parking spot. Tried to start again after a few minutes and it would start right up, then die, then start up on it's own, then die, then start on it's own, etc.. I tried this twice with the same results. On the third try it did the same but after I took the key out of the ignition the starter continued to crank over the engine for about 20 seconds then stopped when I opened the driver side door (could be coincidence). AAA towed it back home and I let it sit and dry out. I've been driving it all day no issues. I don't think any damage was done anywhere.

Thoughts on where I should be looking to prevent this again?

TIA,
Superflo

 

[re_guderian]

Passenger's side windshield dripping onto the ECU. Not a guarantee, but that's where I'd start. I've had the AT Temp light come on once during a massive rainstorm on the way to Tucson 2 years ago. I solved it by not driving in massive rain storms to Tucson. It's worked well so far...

edit: -> on a slightly less smart-ass-y tone, my carpet gets wet on the passenger side floorboard when it rains REALLY hard, and I know I have a leak in the windshield there as i've seen the drops form there. It's not fire, but it's smoke, so-to-speak, and it doesn't rain often enough where I live to have the windshield replaced yet.

 

[Sandroad]

Any chance you have an aftermarket remote starter installed? Is the ignition switch operating smoothly?

 

[TXLX100]

I'm going to venture to guess water intrusion into a fuse panel/module or you have a fuse bad/going bad. Or a bad ground even perhaps. If it's acting crazy, sounds like water or jumped backwards.

Has the windshield been replaced?
Was it jumped off recently?

Start at the battery and work your way into checking the electrical system. The smaller fuses may look good, but may have internal failures you may not see with the naked eye (just chased something like this in another vehicle).

 

[rusty_tlc]

I always check grounding first, low fruit and pretty often the cause of a multitude of weird electrical problems. Microprocessors act strange when there is resistance between the circuit and ground.
Check all the wires, body to frame, engine to frame etc.

 

[Superflo]

Thanks guys I'll have a look see starting with the passenger side area and fuses. I poked around there for a minute this morning before work but it was bone dry. My ac cond drain hose is plugged up so the water drips back into the passenger footwell but I am confident that's not the cause. And to answer the questions, my vehicle is completely stock, I have not had the windshield off or replaced recently, vehicle was not recently jumped.

 

[joseywales]

Any success in finding your issue? Mine is doing the same thing (AT Temp and brake light flickering).

 

[uHu]

For this problem I would always start according to the second posting here. Unscrew the gloves compartment and check the Engine ECU for water, corrosion, plugs, etc. It's really easy to get to. Just don't unplug or yank the yellow airbag plug at the top of the gloves compartment.

 

[joseywales]

Ok. If it's water related, does drying it out typically solve the problem? (Assuming it isn't coroded to hell).

 

[Keowee]

I had similar problem with a car after the winshield was replaced. Water was leaking into the ECU causing it to shutoff the engine. Ran normal again after the leak was sealed.

 

[brosama]

As others stated, check the windshield. Run a hose over it to get a good amount of water on each section, checking for leaks along the way.

Passenger side windshield leaks are not uncommon. I had one from the top of my A-pillar due to a bad windshield job (like others). Ended up getting it replaced by a reputable shop that did it right.

 

[joseywales]

I went through the same thing with my 80 series. Thanks guys.

 

[joseywales]

So I took apart the glove box and sure enough, it's a bit wet there, but the ECU was dry. Don't know if it would be erected by a bit of moisture, but since there was water on the trans controller etc, I'm hoping that's the cause. Did the pin 7 while I was in there. Also noticed somebody had put a bit of silicone at the top of the windscreen on the p-side. I'll take it to my glass shop buds and get them to seal it up properly and hope that clears it up.