I've been struggling with the dash warning lights on my 83 244 (diesel).

The altenator seems to be charging fine, had it checked in the car. The battery light, the park brake light, the brake failure light, and the yellow "bulb"? light never go out. I have run a ground wire from the altenator to the block, and to the chasis, but it doesn't help. I unhooked the red wire from the loom at the fire wall and checked for power. Power on with key on. Pulled the red wire from the altenator. Power on with key on. (continuity test proved it the same wire). With the wire interupted, either from the junction block at the fire wall, or removed from the altenator itself, the warning lights go out. Although I can't prove it with the simple tools I have, I believe the altenator is NOT charging when this is unhooked. When the same wire is jumnped directly from the battery, it puts a load against the engine, enough so to bog it some, and there is substantial resistance (bright blue spark--wire starts to heat and melt the insulation). I have tried the archives but haven't come up with anything that I haven't tried already. So, I am at a loss. Any ideas are certainly welcome.

Thanks!

Leonard

When the alternator was checked, it was in the car, right? Were any of the wires disconnected from it for the test?

The wiring harness in your Diesel may or may not share characteristic problems with the gas-fueled 240's or those years. Look for a gray connector mounted on the firewall about midway side to side. Look at the insulation on the wires going to the engine, is there evidence of crumbling insulation?

The charging system is connected to the warning lights that you mention. Those lights (oil light is different) get power from the key in position II, and the ground side runs to the alternator. It is that thin red wire on the back. With the engine stopped, the ground is OK and the lights light. With the engine running, (1) the small current coming to the alternator from the lights makes a magnetic field on the rotor, enabling the alternator to charge. (2)The ground is effectively lost so the lights go out.

So, that thin red wire may be your culprit. If it is grounded somewhere else, the lights stay on, AND the alternator doesn't charge. If the wire is broken or not connected, the lights won't come on, and there is no charging. You can put in a by-pass wire between the connector and the alternator, and leave the old one in place but capped off.

Also, check that there is a good ground from the alternator frame to the block.

I hope this helps.

Good Luck,

Bob

:>)

Thanks for the response, but unfortunately, it isn't the red wire. I have even removed it from the wiring block and run a new wire from there all the way down. Is there a ground strap or wire from the cluster to the body that could have come loose? The cluster has never been out of the car. The wiring is in good condition with the exception of the oil sending wire, which still functions correctly. This is a very clean car, including under the hood, with only 123K on it. I know this is something very simple, just a matter of finding it.

Leonard

OK, let's go over what we do know. The warning lights go on when the key is in position II, right? Then the car is started, the warning lights continue to stay on, right? That can only mean that the warning light system is getting a ground somewhere other than at the alternator brushes.

When the system works, that voltage arriving at the alternator brushes is reduced from full battery voltage by having the warning lights in series in that circuit. Putting full battery voltage on that spade lug on the alternator may have damaged the voltage regulator and/or the rotor windings. I don't know what the voltage should be.

>>The wiring is in good condition with the exception of the oil sending wire, which still functions correctly...<<

Does the oil sensor wire have crumbling insulation? That wire goes through the under-the-engine harness, along with the thin red wire to the inst. cluster and the fat red wire which carries to charging current and terminates at the starter. If insulation failure is visible on one of these wires, they are all suspects, especially the thin red. Also, there are some metal clips that hold the harness in place, and over 19 years they sometimes chafe through the harness cover and the wires inside.

When you had the by-pass wire in place, what worked and what didn't work? You had both ends of the old one isolated, right?

I am using the Volvo Service Manual 1984 Wiring Diagrams, there may be one for the 1983 model. Part number TP 30678/1, 6000.6.84 Call 1-800-25-Volvo or visit http://www.volvotechinfo.com/index.asp and get one for yourself. I got it when I got my 1983 245GL, in 1991, there may be a newer part number. The diagrams are not repeated in any other shop manual, and the book is well worth the price.

Good Luck,

Bob

:>)