Hello all,

I've got what I think is the most common Volvo problem ... an electrical gremlin. I've reviewed the archives for previous posts but have been unable to find a good answer or possible cause of my problem. Here it is:

The car is a 1991 245 (B230F). Recently it is unable to hold a charge while running and as such has stranded me on multiple occasions. The problem is intermittent and has no apparent pattern. Symptoms include all instrument cluster lights all on (the bottom strip), erratic RPM and speedo readings, quick voltage drops (on my gauge), and mysterious radio on/offs. I once parked (for 5min), removed, the key and filled my baby with gas only to get back in and find the battery had completely drained. (the voltage read out before parking it was around 12V ). Most recently, it lost all power while driving on the highway at 80 km/h. Mysteriously, the instrument cluster lit up, the voltage gauge dropped, the rpm gauge bounced around, the speedo dropped to zero, the radio turned off and the fuel pumps shutdown. Remember, this does not happen all the time.

I have tried replacing the battery, had the alternator rebuilt (including new brushes and voltage regulator), and have verified that all the wiring under the hood is in tact and in good conditions. I disconnected and cleaned every ground under the hood I could find. Current flows as it should from the battery to the starter to the alternator etc. I cleaned all fuses and the fuse block and covered each connection with dielectric grease. The entire dashboard is pulled apart and I still can’t track down the problem. I cleaned and tightened the grounds on the steering column

I did quite a few tests over the weekend with the multi-meter. This is what we found:

One:
Immediately when I start the car the instrument panel lights light up and the voltage gauge starts dropping. At this point the battery and alternator read 11.5V and slowly drop. The small connector on the back of the alternator produces 4.5V.

Two:
When I press the gas to jump the engine from 800rpm to 1500rpm the instrument panel lights go off and the system starts charging again. At this point the battery reads +/-13V and the alternator about the same. But this time the small connector on the back of the alternator produces 11.5V (which to me is fishy).

Three:
With everything off and the key removed the only current I get is from the clock circuit (which tells me there is no current leak when the car is off … I think). This is the same whether I turn the car off when the electrical system was and wasn’t charging.

Four:
I have noticed that me grabbing some of the wiring harnesses behind the instrument cluster and pulling them does make everything go back to normal sometimes. I have tried to isolate the wire but with no success.

I am now starting to think the problem is linked some how to the small connector on the back of the alternator which I think sends the signal to the charge light in the instrument cluster. The instrument panel charge light is in turn connected to the other instrument lights that are on including the service light, the replace light bulb light, the parking brake light, and I few others I can’t recall at the moment. I still can’t connect this system with the RPM, speedo, and radio problems other than the fact that when the battery is dead there is not enough power to run them.

Any ideas? Could it be the little connector on the alternator, the ignition switch …? Your help is always appreciated. Thanks ahead of time.

Kindest regards,

Greg