Please HELP!! '85 Supra charging problem......an advanced problem...

[sbarc]

This story is a bit long.....please stick with me....

I've got a low mileage 85 supra.....69,000kms (43,000miles). This car is rust free and has never been a problem. After my second kid was born my Supra got put on the driveway beside the house (mostly in the shade except between 11am and 1pm. I live on the west coast of Canada in a cloudy wet climate like Seattle (or London, England) but the summers do include a few months of decent sunny hot (warm) days.

This problem is a water related issue.

After 5 years of neglect, I insured the Supra and washed it up and was excited to get her back in my life. After the wash.....I decided to dry it off with a trip down the highway. 50 feet out of the driveway the charge and brake light came on.......classic alternator problem.....odd on such a low mileage car....hummm? I checked the regulator and it was dead. I popped out the regulator and put in a new regulator. Car started up fine and problem was fixed....or so I thought.

It was summer and it hadn't rained

A week later I decided to spray wash the engine to tidy her up. I washed the motor and after that I started it up and the charge and brake lights came on after 50 feet of driving. I was really puzzled by this as I drove straight home.

I checked the regulator and it was dead. I installed another regulator and she was fine again.

The problem was beginning to show a pattern.

A few days later while driving we had a slight mist of rain for a couple of minutes. The roads barely got wet and I only used my wipers for 30 seconds max. The charge and brake light came on again. Once home I confirmed the regulator was blown.

This car is original and has never had any problems. I checked all wires in teh engine compartment and there was no sign of a mouse chewing wires in the engine compartment etc. The passenger compartment has never had any water damage....or the rest of the car for that matter..

Currently it is 2 years later......I'm free to deal with the Supra and want to get her back on the road.....but I've got to sort out this annoying problem.

The Toyota factory manual says very little.

The instrument cluster charge light does not come on ever with the other warning lights when the ignition is on and the engine is off. I spent 45 minutes dismanting the dash this evening to replace the bulb.....but the bulb was fine and the new bulb doesn't light either.
The Toyota factory manual says this light not lighting is caused by the following.....ignition fuse burnt out (fuse is ok)....charge fuse is burnt out (charge fuse is ok)....light bulb burnt out (bulb was checked and isOK)......or regulator is burnt out.......this I haven't checked but replacing the regulator again won't fix the original problem that is shorting out and burning out the regulator.

I did find 2 pieces of cloth tape on the windshield motor int he engine compartment that were all dried up...they were covering holes and maybe water was getting in these holes on this electric motor and shorting out the regulator?? I removed this old tape and cleaned the area on the sides of the electric motor for the windshield wiper motor and covered these holes with black electrical tape.

Anyone have any suggestions?

This is a rust free car that never had this problem before she was parked on the concrete driveway beside the house. the rest of the car seems fine although the paint colour is slightly faded and the rubber seals for the door windows are a bit dry from the sun.

We've moved to a newer house and the Supra has her own garage and is one of two sundays drivers I own....so she is now very well taken care of.

Steve B

[Tercel GTS]

Get the alternator off and have a local rebuilder check the brushes and rotor. The initial problem could have been when you sprayed off the engine. You may have blown grease/dirt/chemicals into the alternator. Whatever may be in the alternator may be water soluable and wetting may reestablish the problem. Also the chemicals used may have attacked the brushes.
Another note, if the field circuit in the alternator is not complete the bulb should not work on the dash.

[sbarc]

I'll get the alternator down to a shop tomorrow.....but the first time the regulator burnt out was after a simple washing of the paint job with the hood closed and no cleaning of the engine compartment. And I didn't spray the underside etc......just hand washed the car and rinsed it off with a garden hose.

Thanks very much for your help....it is MUCH appreciated.......this problem has me pretty frustrated and I'm someone with many engine rebuilds and alternator and starter motor rebuilds etc under my belt.

Steve B

[bgrieger]

Just some suggestions..some may be covered by you already.

I take it you're watching the actual voltage output with a little volt meter?

Put a fresh battery in there after 5 years of sitting?

Taken a look at the condition of the wiring in the car to ensure the alternator leads are good and the ground wires are all in great shape? (wires corrode inside out, too much copper oxide leads to high resistance in the system)

Spiking alternator output tends to toast regulators, and a bad ground or a short may be a source of trouble.

Don't you just hate tracing electrical problems?

Bob

[sbarc]

Originally Posted by bgrieger

Just some suggestions..some may be covered by you already.

I take it you're watching the actual voltage output with a little volt meter?

Put a fresh battery in there after 5 years of sitting?

Taken a look at the condition of the wiring in the car to ensure the alternator leads are good and the ground wires are all in great shape? (wires corrode inside out, too much copper oxide leads to high resistance in the system)

Spiking alternator output tends to toast regulators, and a bad ground or a short may be a source of trouble.

Don't you just hate tracing electrical problems?

Bob

Battery is pretty fresh.....replaced it after the car had been sitting for 5 years.....so battery is less than 2 years old I figure. The battery terminals are very clean as are the battery wire contacts. I haven't checked the negative ground contact next to the battery. I'll double check that and other contacts. The wires appear to be in great shape.

How do you check the wires? Resistance test of some sort (same sort of test as plug wires)?

An update.....
I took the alternator to the alternator/starter motor repair shop today. These guys only fix alternators and start motors....so they are fairly knowledgable to say the least. They bench tested it and it is dead....which is sort of good news I guess and it had one wicked hum that wasn't a bearing noise.

But why was it dead? The guys explained it to me...

After the car had been sitting for a few years.....I had to move the car to powerwash the driveway. I didn't charge up the battery (no time....too rushed to bother?) and instead I just used jumper cables and moved the car. It wouldn't idle at all....the battery was so dead....so I warmed it up a bit and moved it.

It seems running a Toyota with a dead battery causes the alternator to run very hot.....this fried the stator (sp?)....these are the copper wires wound around in the altenator. The first sign of water caused the stator to short and fry the regulator.....or at least this is the working theory.

They are checking the alternator over and will give me an estimate to repair it.

My hope is the problem is restricted to the alternator. I'm looking at replacing the unit with a re-manufactured unit from Toyota, but I'll have to see what they say about the original unit. To be honest I'm not keen to get the old one fixed.......I want to get away from that unit after all the grief it has caused me.

I'll post an update on the final outcome which may help others.

This advice is from the Alternator repair shop.
Oh.....and if you wash your engine.....keep the engine running......this prevents a drop of water getting in the alternator and resting on both rotor contacts that the brushes sit on which shorts out the regulator. I've never had problems washing Toyota motors but I'll keep the engine running in the future......just to be on the safe side.
Steve B

[Tercel GTS]

Don't worry about it being the same unit. Parts aren't readily available for those anymore so most likely they will use a core to salvage a stator/rectifier assembly from. In a worst case scenaio they may sloder larger diodes onto the rectifier. Either way if you get a toyota reman you're basically getting the same thing, just prettier. Just make sure they don't get you a 'universal' new replacement. Easiest way to know is an adapter plug at the alternator.
My shop would charge around $55usd to rebuild the one without a built in regulator.

It doesn't matter what brand car really, starting one with a dead/bad battery can easily overwork the alternator and cause failure. GM cars with cs-130 alternators are the easiest to mess up. Fords from 88-93 may catch on fire.