Problems...AGIAN

MrPants · 10-13-2003, 04:25 PM

the car is not starting again. everymonth i temporarily 'fix' the problme but it always comes back. things that have not solved the problem:
new starter motor
cleaned other grounds
new ground cable
dealer looked at weird electrical problems: replaced fuse box
new battery
new battery 2 weeks later

the car just wont start cranking at all without a jump. occaisionally the battery light comes on, usually when using the turn signal.
i just went out and started the car. 12.7V with the car off, 11.1V while starting, and then 12.1V with the car running.
should i look into getting a new alternator/if so can i rebuild this one on my own? or could it possibly be the voltage regulator?

pearldrum · 10-13-2003, 04:31 PM

Supposedly the alternator rarely goes out, and it's usually the voltage regulator. But, my Alternator went out about 4 months ago, had it rebuilt for I think $100. Make sure to get it tested before you get it rebuilt. Many auto-stores will test them for free.

Roger Hall · 10-13-2003, 06:16 PM

FR Wilk Sells adjustable voltage regulators, I would go that route first its cheaper than an new alternator.

Roger Hall · 10-13-2003, 06:59 PM

My bad I could have sworn that you sold them must have been someone else.

MrPants · 10-13-2003, 07:01 PM

socal speaks highly of the adjustable voltage regulators but i dont know where one would get one. also, why would i want to adjust the voltage?
i can have an autoparts store test the alternator but can one test the voltage regulator as well?

Porsche944 · 10-13-2003, 08:13 PM

Your car is 19 years old, and alternators do fail. The main problem is age and thermal cycles.

The magnet wire that the windings are made of is coated with a layer of varnish. After the windings are formed/wound and the electrical connections are made, the entire assembly (stator or rotor) is dipped in varnish, and then the assembly is baked.

This baked on varnish provides electricial insulation and mechanical support for the wires in the windings. This mechanical support is especially critical for the windings/wires in the rotating part, or armature.

Over time, the process of heating and cooling will eventually cause the varnish to crack and flake off. This isn't as much of a problem for the stator windings (which don't move) as is is for the wires that run from the armature windings to the slip rings.

When the varnish flakes off of the slip ring wires, the wires can be broken due to centrifigual force. When either or both of these wires break, the voltage regulator cannot excite the armature windings, the armature does not generate a magnetic field, and the alternator's out put goes to zero. This is exactly what happend to the original alternator in my '84.

Have the alternator tested. As was mentioned by others, several places like NAPA, Pep Boys and Auto Zone will test your alternator for nothing because they want to sell stuff. To beat them at their own game, call first and ask what a rebuilt Bosch alternator will cost, and what the core charge is. You'll no doubt get a suprise or two.

Rebuilts are OK, but you have to be carefull. Don't do mail order. I got burned by Vertex, and I get a much better product locally. The point here is, I trusted Vertex and thier workmanship sucks.

I used to run an electric motor re-wind shop in the Navy, and had I inspected the Vertex junk before I installed it, I would have discovered that the rebuilt unit had failed for the same reason as my original alternator.

When the Vertex unit was "rebuilt", the windings were not dipped and baked, the "rebuilder" used the wrong gage wire to replace the armature to slip ring wires, the replacement wires were held in place with grey RTV, and the solder joints exceeded the "bigger the blob the better the job" specification. Needless to say this "rebuilt" alternator lasted about 30 days.

Should you get a rebuilt, inspect it first, and then have the sales person test it while you watch. When you inspect the part, spin the shaft and listen to the bearings. Watch the shaft to see if it is out of round or bent. Give the part a good sniff. Fresh varnish has a distinctive smell which is not anything like fresh paint. Look at the windings and make sure they are nice and shiny. Fresh varnish ranges from a transparent yellow, to a transparent orange/red. Dark/black varnish is old. Check the threads and the keyway on the shaft. Check the mounting hardware, through bolts/nuts, the noise suppressor (little black box on the back), and the voltage regulator. Those parts should be new.

As a final note, this would be a real good time to check the major electrical cables and connections for the battery, starter and alternator.

profssr2017 · 10-14-2003, 05:57 AM

Excellent advice!

SoCal Driver · SoCal Driver's Garage

IceShark has the adjustable regulators. Comes with the brushes intregal with the regulator. Still does not fix other problems you may have with an alternator. But at about $22 it's worth a shot.

MrPants · 10-20-2003, 12:28 AM

for the love of god!!
after 3 hours of screwing around i finally got the alternator out of there and had it tested, passed. charges 14V. i even made sure to watch the guy test it.
does anyone have ANY idea what my problem could be?