I am one of the few here that loves my dealer.

We have driven over 600K miles in 4-700s, 3-850s and 2-XC70s - We have only suffered 3 breakdowns, and no problem has involved more than one part.

One thing to do with older Volvos is to unplug all connectors, examine the pins, male and female, clean them as much as you can, and add dielectric grease - zip tie together any that you can. I did one connector every week so that if an issue developed, I could find the problem.

Check the grounds as well - If there is no ground wire (such as a headlight with a plastic housing) the item itself must ground to the engine or the body of the car.

Once my '90 744TI stalled whenever I used the high beams - turned out to be the headlight grounds, stealing the ground connection from the ignition! Its in the 700/900 FAQ!

Have you read the FAQ? - many items on your car are like 700s - My '88 745 GLE had a 240 engine.

Also check your engine grounds - possibly one at the top of the engine and one near the bottom.

Check the pins to the AMM - sometimes they push into the connector - This plug is one of the few that gets unplugged when the air filter is serviced.

Volvos compensate quite well for wear and tear and you might have more than one issue..

Perhaps a dealer tech can find the problem - a couple of times my dealer offered a one hour inspection with a written report for free!

Most dealers cannot charge more than one hour's labor for troubleshooting - my son-in-law is a Subaru tech and that is all they charge as well.