I just bought a 1989 740 GL with 87,532 miles on it; it looks beautiful cosmetically; the original paint is gorgeous, no dents or dings, interior is unbelievably clean, and it runs OK. Idle is rough and the transmission doesn't shift as smoothly as my '89 240DL Wagon. Those things don't worry me though; it's the electrical stuff that eats away at me.

Anyway, the fuse #5 circuit has a dead short in it somewhere and I'm having a hard time finding the source. The seat belt signal realy stays on constantly so I have removed it. BU then that seem sto screw up ALL of the connected circuits on that fuse. First question: does this model have any consistent problems with this circuit and what are the most likely causes? I have removed the dome light per a suggestion elsewhere on this website, but the short still exists.

I did a little more investigation: I pulled out the fuse block and one-by-one disconnected the three spade lugs on the #5 fuse. Looks like the short is in the dome light/engine compartment circuit, e.g. had low resistance, .2-Ohm, on the circuit to ground with the negative battery terminal removed. I isolated the engine light circuit and it appears as though I have found the culprit SOMEWHERE in the dome light circuit, which is a real hairly one! However, when I disconnect that lug, put in a new fuse, reconnect power, put in the seat belt relay and turn the car ignition on, the seat bealt realy still won't quit, none of the other lights on that circuit work, the radio sort of works. Ay yi yi, electrical stuff drives me crazy! I had to give up after a couple of hours, but this will stay on my mind until I figure it out. By thw way (BTW) I have a Haynes manual the only covers 82 thru 88. Can anyone verify if there are significant differences between the 88 and 89 model year circuitry?

TIA (thanks in advance)
Don Lewis
Santa Barbara, CA
wet and rainy for weeks now!