Volvo: 240DL Electrical Problems, accurate diagnosis, stop signs

Question
Help-quickly. I leave for vacation Wed. AM (June 30) and would like to leave the car with my mechanics while gone. They have looked at it 4 times w/o solving the problem.
CAR: 1990 240DL, 123,000 miles maintained well.
PROBLEM: Started with radio cutting out when I applied the brake (intermittent). Did this for at least 3 weeks. Then, started idling rough and began to stall at stop signs, braked pauses (intermittent). Then we noticed the headlights dimmed when the brakes were applied (intermittent). The auto door locks don't always respond to the key (intermittent). The horn goes out completely (intermittent).
Had the car in 4x, they cleaned fuel injectors (for the stalling), checked and tightened all the wires & grounds. The car works fine for about 2 days, then the problems start up again--always with the radio (which is a SONY installed a few years ago). Now it stalls when braking on a turn into a driveway or parking lot (also intermittent) and the horn is out again. My mechanics are reluctant to replace the wiring harness believing it is probably one small thing causing the problem. Problem is the car doesn't always act up for them even when they have it for 2 days. What should I do?

Answer
Hello Andie! I wish I could give you an answer to your problem. However it sounds like there is too many things wrong with the electrical system to give an accurate diagnosis through an email. I would make sure the battery, alternator and all wiring is ok first. It would be best to let someone who knows Volvo to work on the car for you.


Jimmy