I am hoping that some else has had this crazy idea and tried it.

I've just replaced the automatic transmission in my son's '84 760 Turbo with a manual transmission. I was told by a service guy at the local Volvo dealership that I could replace the relay in position "I" of the fuse box with relay from a manual transmission equipped car, attach the wires from the manual transmission according to the wiring diagram in the Volvo shop manual, and I'd be good to go. He also told me that I could use the transmission relay from a 82-86 240 series as it was the same part number. Well in spending a fair amount of time both pouring over the wiring diagrams and looking at a 1984 760 GLE with a manual transmission and comparing that to my son's 760 Turbo there seems to be some differences that I can't get around. Yes the harnesses are different, but I figured that if they ran to the right places the automatic harness could be used. The symptom is that when we press the 5th gear button on the stick-shift the lights on the dash and center console come on and the car does NOT shift into overdrive.

So here is how I have tried to wire up this beastie:

There are three connectors in the wiring harness that seem to deal with the transmission:

1. A white one with three wires: white, brown, and blue

2. A dark blue one with three wires but two connectors: two blue wires in

one connector and a gray wire.

3. A gray four wire connector: black, blue/red, two pink, and blue/green

wire.

I figured out that the gray four wire connector must be the back-up lights and have run two wires from the backup light switch on the drivers' side of the manual transmission to the black and blue/red wires on the gray four wire connector. I purchased the matching connector from another car and it has a pink wire that ties the blue/reen and two pink wires from the harness together.

The rest of the connections are as follows:

Transmission side Wire Harness/Fuse box side

Yellow (solenoid) to White wire (in white connector post 87 on

manual relay)

Brown (OD Button) to Gray wire (in blue connector to post 86 on

manual relay)

Blue (OD Button) to Blue wire (in blue connector to post 15 on

manual relay)

Red (Inhibitor Switch) to Brown wire (in white connector to post 85 on

manual relay)

The only other difference that I can find from the wiring diagrams is that the Blue/red wire to the instrument panel needs to be moved to position 5 instead of position 8 where it is on the automatic version of the '84 760 Turbo.

Any thoughts on whether this is possible or not out there?

Maybe some schematics might help?

http://www.geocities.com/janicerennie/images/conversion/odrelay1.tiff

http://www.geocities.com/janicerennie/images/conversion/odrelay2.tiff

Rene

Rene,

Thank you for the diagrams. Unfortunately I can neither print them nor read your notes. Could you import them into MS Word and e-mail them to me?

Thank you,

Chris Herrin

p.s. I have the same diagrams, but unfortunately don't have your notations

Your post states the fifth gear light in the instrument cluster comes on when you push the OD switch. That wire is supposed to be connected to terminal 87 of the OD relay, which should also connect to the OD solenoid. The original wire to the upshift light was grey (yellow on M46/OD cars), and connected to terminal 87a. If you are still connected to terminal 87a you will have reverse indication of the OD function.

Do you have terminal 85 of the OD relay connected to the fourth gear switch of the OD? The original relay base in your 84 car will not have a wire there.