j.kenzie@sbcglobal.net

Hi,
For the past couple of days, after start-up, all my dashboard warning lights remain lit, including the "!". The ignition switch is about 3 years old. Any ideas? I should add that sometimes I can remove the ignition key without shutting off the ignition. I have to turn the key hard to the left to be sure the ignition goes off, suggesting a loose key to switch connection.
Thanks in advance,
Dave

Maleficio

Your Central Warning unit is stuck in start-up mode where it shows all lights working. It's installed behind the left footrest on the driver side. Replace it. I got a good one off eBay for $30.

Mrmerlin

usually when the warning lights stay on its because the alternator isnt charging or the blue wire is broken to the exciter circuit.
What was the last thing that you fixed?

check the ignition switch as it could be loose 2 screws hold it onto the rear of the key cylinder.
Check the 14 pin connector,
the battery connections clean them plus the ground

j.kenzie@sbcglobal.net

Sounds reasonable. I bid on one on ebay. Thanks

j.kenzie@sbcglobal.net

Thanks, Stan. I haven't fixed anything for quite a while.. Brakes, 5 months ago. I haven't been driving the car that much, and I find problems surface with disuse. I will check connectors.
Dave

fltechpilot

As Mrmerlin mentioned this sometimes happens when the alternator isn't charging. Check to make sure the alternator belt tension is right.

j.kenzie@sbcglobal.net

Hi,
Well it looks like Stan and Fltech are in the right ballpark. Today my car died after about 10 minutes of driving and would not restart. It jump start easily and ran great after charging with the second car for about 5 minutes. I drove it home, about 3 miles and had no problem. I put a battery charger on and it was drawing about 10 amps charge. After 6 hours, it starts and runs fine with no warning lights. During the initial charge after jumping, the warning lights stayed lit, and the voltmeter showed 10.5 volts, until 3-4 minutes when the warning lights suddenly went off and the voltmeter jumped to 14 volts.
I hadn't driven the car very much in the last two months, so I am hoping this is all just a very low battery that needed a good charging. The alternator is 4 years old high output Mechman unit from 928MS. The belt is very tight.
Any further ideas?
Thanks,
Dave

Randy V

Sounds like a failing alternator.

Have you tried cleaning the multi-pin plug?

Maleficio

Cool.

j.kenzie@sbcglobal.net

Thanks Randy, I will look at the 14 pin plug. Would the car run great with a failing alternator, 14 volts on gauge?
Dave

Randy V

Sure.

I was considering this information you stated -

During the initial charge after jumping, the warning lights stayed lit, and the voltmeter showed 10.5 volts, until 3-4 minutes when the warning lights suddenly went off and the voltmeter jumped to 14 volts.

j.kenzie@sbcglobal.net

Hi Randy,
My theory was that my alternator needs a battery voltage to charge, and mine was discharged to 10 volts or so. During jumping, while attached to the donor car, my battery charged somewhat, and the other car also showed normal voltage to my alternator, thus letting it energize and begin charging. This may be a fantasy of mine about how alternators work, but if a good battery charge solves my problem, maybe it is correct. Otherwise I have to look at buying a new alternator.
Thanks,
Dave

Toybreaker

Troubleshooting a problem like this can be rather overwhelming at first.

... So many symptom, so many places for the train to fall off the tracks

It can be tempting to just start replacing parts, but it really is much better to find and repair the fault.



I find it's easier to break things down into smaller chunks and handle things a step at a time.


Verifying that there is an excitation voltage available at the back of the alternator would be a good place to start.



Just hook your voltmeters red positive lead onto the post the blue wire goes to on the back of the alternator, and put the black lead to a good ground. (the alternator case is a good choice)

Turn the key to the on/run position, and report back what you see.

j.kenzie@sbcglobal.net

Car starts and runs great right now, after charging the battery. When it was dead I was on the road, and did not have a voltmeter. I have a solar battery charger installed since I don't drive the car that much. On close inspection the charger's crimp to battery post connector was broken off. So while I thought I was keeping my battery charged while it sat, I was doing nothing.
If car fails again, I will measure alternator input voltage.
Thanks,
Dave

Landseer

Bad alt, probably brushes sometimes making contact.
Not exciter circuit probably, as alt would self-excite at driving rpms.
(though advice to track exciter wire through 14 pin connector, and to alternator, is still a good idea at the time you are swapping alt.)

Next time it happens, park, tap alt very lightly with hammer, warning lights will probably go out.

Warning lights are extinguished by alternator charge on 84.
That was a new change to the central warning system that year.
This is an entry in the section on central warning system in the 928 Electrical training document within the CD. So I think this might be what your car is facing.