Howdy,

I have a 1982 240 GL with the wiring harness problem. The big 8-pin connector on the firewall had major problems with the wires. The warning light would stay on almost all the time.

While replacing the head, I used the opportunity to replace about the top six inches with a connector that was in much better shape getting rid of the bad wires.

Now, the lights stay off for the most part but seem to flicker on and off as I accelerate or deaccelerate. I am assuming this happens because of the movement of the engine. It is all the lights at once, not just one.

QUESTION: Is there like a common ground someplace or someplace where power would be added via a short to cause all the lights to flicker?

Thanks, Jim

Jim-

Put a by-pass test wire between the spade lug on the back of the alternator and the wire in the 8-place connector that's in position #3, a red one. #2 is yellow, #4 is vacant unless you have a carburetor.

If that ends your problem, then you will need to re-build the smaller wires in the harness that goes under the front of the engine. Long, dirty, simple but not very difficult.

Good Luck,

Bob

:>)

Bob,

Thanks for your response. I assume that the spade connector off the back of the alternator is a power lead. If this power is not steady, are you saying this will cause the warning lights to flicker? My head lights don't flicker so it is not like the power is flickering in the car, just the warning lights turning on and off.

Also, if this test proves positive in that it prevents these lights from flickering, how many other wires are involved beside just the red one and do they all go back to that one big connector of the firewall (8-pin)?

Thanks.

Jim

Jim -

The Brickboard is now vailable this is a copy of my email to you.

The wire on the alternator that attaches to the spade lug has nothing to do with the headlights. Here is the way it works:

You may have noticed that the warning lights are on in key position II, this is in order to allow a burned out bulb to be apparent. The lights go off when the engine starts up. What turns them off?

The hot side of those lights is from someplace not relevant here. The ground circuit is through that red wire through the 8-place connector and to that spade lug on the alternator. It goes to one of the brushes. The other brush is grounded. When the alternator is not spinning, the warning lights ground side is from brush to rotor windings to brush to ground. This will fail if the alternator itself is not grounded, but you already chesked that, right?

When the alternator spins, the small current through the warning lights and to the red-wire brush provides a spinning magnetic field which generates the electricity. The ground is lost, the lights go out.

If that red wire gets grounded somewhere else, you get the lights back on. And, you get no magnetic field on the alternator rotor so no charge.

If the warning lights flicker, there is an intermittent ground. Usually that happens inside the under-engine harness when the insulation on the wiring begins to disintegrate. This happens to my experience on ALL 240's given enough time.

Have a look at those wire where they come up behind the alternator. The thick red wire carries the charge current to the battery. The thin black wire connects the oil pressure sensor - through that 8-position connector - to the oil warning light. The thin red wire is the one in question. The thin ones usually show rotted insulation.

The by-pass wire I suggested removes from the circuit the in-harness wire and replaces it with a good lead. I suggested it so you can better identify the problem before going ahead with the harness re-construction.

I hope this helps.

You would be well served to own the Volvo Service Manual, Wiring Diagrams, for your vehicle. Go to www.volvocars.com/lit, choose service, or you can call 1-800-25-VOLVO for personal assistance. The service manuals, sometimes called the "Green Books" are not low cost, but usually not all of them are needed. The one for wiring diagrams is worth every penny. Both Haynes and Bentley get their schematic diagrams from the Green Books.

Good Luck,

Bob

:>)

Bob,

It worked!

The wire on the alternator had fallen off! It had no insolation on it either. Anyway, I put another spade connector on it and atteched it to the alternator and no flickering!

I did find that all the wires down there are bad so I'll always have a project to do when I have nothing else to do.

Anyway, thanks you so much! The BOARD comes through again!

So how much has everyone saved here on the board by the board?

It must be a million!

Jim

Jim -

That little tip is unforgettable to me. I had the 86 in my Volvo shop for it's first real check-up, high idle speed check, brake fluid flush, etc.

The tech/owner (named Nils, has Swedish accent, don'cha love it!) answered my Q about warning lights, showed me the wire handing out there loose. I was embarassed.

The female connector had broken and wouldn't grip the spade lug. It was wonderful to find such an easy fix. I am glad to pass it on.

ALSO - the wire to the oil pressure sender will gound out, too. That will cause the oil warning light to flicker or be on with engine running.

Good Luck,

Bob

:>)