Car power suddenly cuts out and in

[kach22i]

Car power suddenly cuts out and in again.

1990 Geo Tracker, 122,000 miles, electronic control box changed out four years ago. The car has been sitting for two weeks, started up like a champ.

I'm driving down the highway at 72 mph and all electrical power suddenly cuts out and the engine stops running. I change lanes while coasting and heard a faint beeping noise coming from around the glove box (like a thermal warning?). I pull over and as soon as I tap the brakes and touch the ribbed shoulder the power cuts back in, the radio is even on the same station like nothing happened. I drove another 25 miles without incident. It was dry out, no rain or snow.

Short?

Thermal overload of something?

I did not notice any funny sounds before the power cut out.

Ideas and suggestions of what to look for.

[TerryH]

Originally Posted by kach22i

Car power suddenly cuts out and in again.

Ideas and suggestions of what to look for.

A sucker to buy it!

Sorry, I hate electrical gremlins. My spare car has a similar problem. It will run fine for a month, then out of the blue just crank and not fire. Sometime later it will start and run fine. Rinse and repeat. Almost impossible to chase problems when they are so intermittant.

[kach22i]

Originally Posted by TerryH

A sucker to buy it!

Sorry, I hate electrical gremlins. My spare car has a similar problem. It will run fine for a month, then out of the blue just crank and not fire. Sometime later it will start and run fine. Rinse and repeat. Almost impossible to chase problems when they are so intermittant.

The guys at CarNuts.us said to start by checking the grounds, which may be all rusty on my car.

[RANDY P]

trace all your wiring off the battery, and out of the fusebox.

Chances are there is a hub / power splitter that has come loose over the years. I had a Corvette that did the exact same thing. Behind the battery there was one large wire that was attached to a distribution post with multiple wires going to various circuts underneath it that was held on by a 10MM bolt. The bolt came loose.

rjp

[dhoward]

Check battery posts...

[kach22i]

Originally Posted by RANDY P

various circuts underneath it that was held on by a 10MM bolt.

I had to tighten that bolt a few years ago to connect a wire which had snapped off, I'll look at it again.

From Carnuts.us:

Originally Posted by LS1 Mike

Does that thing have a BCM (Body Control Module) Common in GM stuff, even thought that is a Suzuki.
I have not had one fail, but I have heard about some failures that may cause this. It is usually right under the dash.

I'll be looking for things in the Haynes book before going out in the cold with a flash light, hoping to make short work of this short.

[kach22i]

I drove home early so I could continue moving out of my other office and work on the car. As I feared the bumpy brick road on the way to downtown caused the car to lose power several times.

I discovered that any combination of pushing the battery around worked the first two times. However later I tried pulling on the bundle of wires near the battery and adjacent to the nearest power block/fuse junction and that worked too.

To know when the connection was good I left the key turned on in the ignition and jiggled the battery /cables/ 3-fuse blocks. I could hear an arcing somewhere on the engine, perhaps the coil or other critical link/juncture. When the connection is good the beeping from under the glove box can be heard, I then turn the key and the engine comes back to life until the next big pothole (I learned not to slam the hood back down - will cause it to stop).

The battery connections are tight, but the fuse block area is rusted.

I need to trace this, right now in the daylight, cheers.

[dhoward]

Ground wire on the block.

[kach22i]

Originally Posted by dhoward

Ground wire on the block.

I'm putting on my work sweatshirt now, looking for that ground first.

Almost as fun as the Porsche.

[legion]

Originally Posted by dhoward

Ground wire on the block.

Loose nut behind the wheel.

[dhoward]

Goes without saying...

[kach22i]

Originally Posted by legion

Loose nut behind the wheel.

So I'm downtown popping up the hood in front of my office downtown and some guy standing there says; cool car man.

I should have just sold it then. I'm a nut for keeping it.

[kach22i]

Strange short, don't know if this is the end of the story.

I found the ground to the engine block, the other cables went to the starter and alternator. All were very secure, and could have looked worse. I started the car and pulled and tugged on then one at a time, the car kept of running, so I looked elsewhere.

I found a stray wire which I could not figure out where it went, car runs fine without it.

I found another wire oxidized and it broke loose from the fuse block near the battery when I went to inspect it. I fixed it, but the car ran with or without.

Of the three fuse blocks near the battery, the middle one labeled "A/C" turned out to be the one giving me the problem. It became so sensitive from my fooling around under there that getting out of the car or just tapping the top of it it very gently would shut down the car.

My A/C has not worked for ten years, so I pulled the fuse and taped it up to keep moisture out. The car ran fine, so I shut it off and pushed (forced) the rubber fuse boot onto the metal fuse holder plate. The car once again would not start,. so I pulled the boot off the holder and let it float in the air with no downward force to the bundle of wires below.

The car now runs great, I drove it over a bunch of bumpy frozen ice packs along the curb edge at speed with no issues.

Funny thing this short is, I'm not sure I've seen the last of it.