If you rev the motor to 2,500RPM the alternator should kick in even if the dash BAT light is inop. Not a good permanent fix but something in the meantime.

Thanks for helpful suggestions. I've got another cluster coming, so I'm going to try that. I really think the problem remains in the connections, but I'm not ruling out something internal to the diode-trio or even the board jumpers.

Playing with the largest connector seems to make some of the lights go out... playing with the 4-pin connector (power and speedo) consistently takes power away from the cluster. It's amazing to me that these cars are generally reliable, given the importance of those functions and the really poor way the contact is made.

They're all 20 years old now, so in my book, any type of failure is a possibility right down to component level. And chasing intermittents is the worst. Very frustrating for the customer and the mechanic.

I appreciate the suggestion about the bulb contacts and socket, but when this problem presents itself, ALL of the lights go out except for those on dedicated circuits.

I didn't get into the additional tracing and diagnostics I did, but for instance I found that even in "failure" I could get the turn signal indicators to work in the dash. The - pin for turn signal lights goes directly to the 4-pin connector, so I knew I had a consistent ground connection, even when I didn't have the other lights.

I spent a great deal of time working on this thing with it plugged in, pulled out and hanging over by the fan controls, trying to test individual connections on the back.

Thanks again,
--Rob

There are two in Memphis, TN at http://www.pullapart.com

Hello,

Check the 'grain' sized bulb (12v 1.2watts) behind the battery/charge indicator on the back of instrument cluster.

This small bulb is part of 'exciter circuit' for alternator. It supplies voltage to the small red alternator wire. If the bulb's connection is poor or intermittent this might produce the symptoms you've described.

The bulb can be pulled out from its holder. Clean the bulb holder connections (on the flex circuit board too) and the bulb's terminal itself. If you have no spare bulb just use a similar one from other dashboard indicator temporarily.

Also you may change all bulbs as preventive maintenance. New ones may be obtained from IPD or your local parts store.

Hope this helps.

Amarin.

Dear Aye Roll,

Hope you're well. I do have such an instrument cluster. I'll e-mail you with details.

Yours faithfully,

Spook