1982 Volvo 240 DL Wagon. I had one one of the wires coming off the alternator was resting on the oil filter and wire wrap melted and appeared to have shorted out. My alternator stopped charging. I've replaced the shorted wire, but the warning light are still on and my idle is still really high. I'm leary of putting in a new alternator for fear of buring the new one out. Someone told me it could be the Ignition Control Unit. I think that's the box strapped to the rt fender well closest to the alternator. How can I test this unit. Or should I start shopping around for a newer Volvo to own? This one has 232K and I was kind of hoping to keep it going until 300K.

Thanks

Martin -

The harness going under the front of the engine is notorious for messing things up after the insulation has crumbled and gone. On my 1983, 1984, and 1986 B230F 244's I have re-habbed that harness.

The large wire is usually OK. The smaller ones are black to the oil pressure sensor. Red to the alternator D+/61, spade lug. That last is the one giving you problems. When it is grounded the instrument lights are on. Usually the ground goes through the alternator slip rings via the brushes. When the alternator produces current, no ground, lights go out. If the oil sensor lead grounds, oil light is on.

You can temporarily by-pass a bad D+/61 lead with a wire from that spade lug to the other end of it which is in the gray 8-position connector mounted on the firewall about center. If you do this, be careful handling that connector as ALL the leads there have the deteriorating insulation problem. The D+/61 wire is #3 where #1 is black, #2 is yellow, and #4 is empty unless you have a carburetor. I hope this helps.

Good Luck,

Bob

PS You might visit www.volvocars.com/lit and check into getting a Volvo Service Manual Wiring Diagrams for your wagon. I've found them invaluable.

Thanks, that seemed to be the problem. I ended up rewiring three wires altogether. Lights all working properly and alternator is charging now.

Martin

You probably burned out the voltage regulator which is inside the alternator. Which wire did you replace, there are three coming away from the alternator. A thick one which goes to the battery, wire that goes to ground and wire to the dash light.

The ignition control unit has nothing to do with the alternator circuit and if it was bad the engine would not run, someone is guessing.