Hello All,

This Overdrive thing is driving me buggy!!

My OD light has been on for a bit, which of course means my OD is off. Around the city it hasn't created much of a problem, generally 30-40 mph tops. We finally hit the highway last weekend, light is on, I click the button several times and voila' OD light is off, OD is working fine. Stop the car to fill up, back out on the highway, light is on, click the button several times, light stays on but car shifts into OD. Drove 500 miles and as erratic as it has been, it's generally shifted into OD after several clicks of the button.

What's up??? Relay? Switch? Solenoid? Faulty wires? Possibly a combination of things? How easy is it to get to the wiring leading to the solenoid?

Any help would be appreciated as we are vacationing in a community without any capable Volvo mechanics so you guys/gals are my lifeline. Thank goodness for the Brickboard!

I had a number of intermittent OD problems. Light would glow dimmly, sometimes go out when the OD was cycled by the switch, sometimes not. Sometimes OD would drop outand re-engage with the switsh (and the light still glowing dimly). Sometin=mes the light would go from dim to bright with OD dropping out, and would not re-engae when the switch was cycled. Anyway, removed the relay, opened it up and resoldered a couple of bad solder joints. No problems since andit has been over 6 months. I would go with the relay.

I had a similar problem, i could click the button and the od light would ocasionaly go out and i could use od. Otherwise I was limited to third get 50mph tops(aw70).If i got the overdrive to work, and stopped to get gas, when i started the car, no overdrive.Then it was back to clicking the button, but not tooo fast or i would get it(overdrive) to turn on and the od off light would go out and from repeatedly pushing the button,i would accidently turn it back off.I found this to be quite frustrating since it was killing my gas mileage. I bought a new relay and havent had a problem with it since. This was in Jan. The relay was definitely my problem. i hope this helps, good luck, kennethcardell

If it was mine, the first thing that I would do is climb under the car and check the wire and connection to the solenoid. Then , I would swap out the relay with my good spare. My bet is the relay.
steve

OD operation involves 5 components and the wiring that connects them...

1) Fuse 11 (200) or 12 (700/900) supplies voltage to items #2, #3, #4, and #5

2) The Shifter button/switch turns the OD relay off and on

3) The OD relay controls the Upshift (not "OD") Arrow light and Solenoid (separate wires)

4) The Upshift Arrow light ON means the relay and OD are OFF

5) The OD solenoid allows OD engagement when ON, (the "default" Relay state at Key On)

If the Shifter switch turns the Arrow light (#4) on and off, then items 1, 2, and 3 are OK, and the problem is most likely the undercar wire to the Solenoid (#5) or the wire connector terminal at the solenoid.

Less likely would be be Solenoid itself.
Also possible (but unlikely) would be the relay controlling the Arrow light (#4) correctly, but failing to activate the Solenoid.
An internal transmission problem is also possible.

Consider this recent reply to a "check the wiring" suggestion:
"Replaced corroded connector and length of wire with bad insulation. Working perfectly now."
He was having "intermitent" OD failures, and was sure it "couldn't be wiring" because that would be "all or nothing".

--
Bruce Young
'93 940-NA (current) — 240s (one V8) — 140s — 122s — since '63.