where is the relay switch for automatic overdrive on my '88 volvo 740 turbo? thanks?

Question

does speedometer have to be working for the overdrive to properly engage? such as speed sensor to the computer?

Answer 1

no the speedo does not have to work for the overdrive to engage the relay is located in fuse panel, to access this you must remove ash trey and ash trey receiver then cigar lighter element now pull off the small square trim above the lighter receiver to access hidden screw [note screw is angled on a 30 deg. cant left of center. now remove the right side screw [goes in strait] and pull out and downand lay to left side of console leaving lighter wires attached the over drive is towards the back of the panel to the right of center tall and most likely white in color[ other possible colors are black orange or green ] if to be replaced the new one should be the same color as the one removed. most common overdrive trouble is the switch on the shifter and its wiring. the wires break where they flex or pull off of the switch pin terminals i have only seen 2 or 3 cases where the solenoid on transmission went bad. note i.p.d.has a kit to replace solenoid that gives you overdrive without any relays switches or wiring but you cant tow with it as the overdrive stays engaged [trans damage will result if you do] good luck

Answer 2

hobbabob nailed it!!!

<<< 89 740 turbo, 93 940 estate turbo