Okay, I was poking around under my car and saw that the OD wiring wasn't hooked up to some kinda switch near the top of the tranny(M46) on the drivers side. I hooked the wires back up and everything works fine! I did trace the wires and my cars' OD wiring and found its direct wired; theres no relay! When I turn it on in park I hear a small thump , but its just the soleniod, no clicking of a relay anywhere. All the wiring appears to be stock. My last question is this; Does anyone know if this is normal? Anybody elses' volvo OD not have a relay? Thanks

 

I have known them to have a relay. Im not sure then.

 

You need the relay to engauge the over drive only when you are in 3rd gear. Otherwise you will be running the over drive in all gears. Not only will you have no power, but it will wear out the over drive. Can you manually shut off the OD with the switch? When you are in third gear can you feel the OD kick in automatically with the switch on? All Volvo automatics give a little clunk when taken out of park or nutral. Just make sure that the over drive is not on in all gears and that it does kick in in 3rd gear automatically, other wise you are going to want to leave the OD off (I usually do) until you need it (over 60 on the highway etc.). [>:]

 

I've got a M46, which is a 4 speed manual with an electronicly controled 5 gear overdrive slapped on the back. Because of the switch on the tranny(the one near the top that was unplugged), the OD will only engage while in 4th gear. Not automaticly though, only after I turn it on at the shifter. Maybe this was all a misunderstanding so let me refine my question, are Volvos with a M46 commonly wired without a relay?

 

Had a 1984 245 diesel wqhich had a four-speed tranny with OD. The OD was activated through a switch on the shift lever. It was an electrical/hydraulic unit. I believe the switch was wired to a relay which operated the solenoid - the current draw of the solenoid would have made short work of the switch ifit were wired directly. I heard a distinctive click/click sound when I activated it. But I never worried about the relay since the unit always worked until the hydraulic piston began to leak. Then not only could I not use the overdrive, the car wouldn’t go into reverse. Got really tired of pushing it into and out of parking spaces, so I had it fixed. $175. Car had over 200,000 miles so I figured it was worth it. My back did, too.

 

I just got a volvo green tech book for the 77-78 240's wiring diagrams, and it shows that they were factory wired without a relay. Just thought you'd like to know.