Funny Problem Im Having With My 87 760 Turbo

[Andrew Higbee]

so i just bought the car last month dont know why i didnt buy one sooner but im having a problem whenever i turn the highbeams on the car shuts off so i checked the wiring and wires were good so i disconected the driver side high beam and my high beams worked again but doing 80 on the freeway i went to change lanes and used my left blinker and found out the car shuts off with the blinker if you dont have the high beam connected

and must i add the only the driverside head lights go with the blinker

any info helps

[Three Fat Tigers]

'86 was the worst year ever for Volvo's, '87 was the next in line, especially for electrical issues. Odds are you have some sort of wiring harness failure out in the engine compartment, either from bio degradable insulation where the insulation on individual wires literally just crumbles away, or much less likely, the car may have been in an accident where the harness was damaged where it can't be seen easily.

I'd start by examining the harness for signs of rot, then move on to testing the harness. You may have to unplug the entire harness and test it for integrity, I'd start with the right side, unplug everything connected to it in the engine compartment, then the main plug up under the right corner of the dash, then check at that plug for continuity between any of the terminals, which would indicate an fault/short. Most likely you will need a factory wiring diagram book to accomplish this, I don't have one for this year, though blarf has one on this page for an '88:

http://blarf.homeip....lery/simplelist

scroll down to TP 31075/1

however '88 was a major redesign, so may not be of much use. Not sure if you can still buy the book from Volvo, but if so it would be around 30$, otherwise you might ask over at turbobricks.com, odds are someone there will be able to help you out with an pdf file. While your are there you might as if the dropbox.com files are still available and if there is an update to the user name/password, see:http://www.brickboard.com/FAQ/700-900/ElectricalCircuitsRelays.htm#WiringDiagramsWebsite

It's not really hard at all to replace the harness sections, might be hard to find a suitable donor, but otherwise with some basic skills and a bit of time almost any harness can be repaired/rebuilt. If it might be relevant in the search, if the engine dies where the tachometer drops like a stone, the ignition is being cut; otherwise if the tach stays with the engine speed as it drops off, it will be the fuel system.

[James A Sousa]

I had the same problem - it's in the FAQ at Brickboard.

Clean the grounds in the left front fender including the terminal strip, the mounting of the power stage and the mounting of the frame of the ABS box.

You should check all grounds including straps at the top and bottom of the engine and any component that does not have its own ground wire.

Consider cleaning all connections in the engine compartment, adding dielectric grease, and zip tying any connectors that you can. Look inside each connector to make sure no pins have been pushed back.

I did one connector each week so that I knew where to look if a problem arose.

The FAQ at Brickboard is amazing.

[Andrew Higbee]

cool thanks for the advice just a qustion where the grounds hook in theres 4 on the passenger sidde and 2 on the driver side is there grounds missing or is that the way it should be

[James A Sousa]

There are not too many grounds that actually go to the strip. The wires may be for components that are mounted to a plastic part, like a light bulb in a plastic socket.

This may be why the headlights trump some of the others.

I think that the power stage grounds directly to the body, and if you remove it, you may find that the bottom has some corrosion.

If you follow the wires that go to the strip, they do not go to everything, that is why you should check any connection of an electrical component to the body or engine.