88 240 DL transmission problem

My Volvo will not go into overdrive. The overdrive light does go on and off so I think the switch works. I am assuming that the solenoid is bad or the relay is bad. What would be the proper way to diagnose this problem. Thanks for any help.

Reply to
zforce77
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Have soemone engage and disengage the OD while you listen under the car. No click at solenoid:

Use a volt meter to test for voltage at the solenoid. They are inexpensive at just about any X-mart (like $8-12). Handy to keep in the car anyway to test for voltage and test bulbs and fuses and such.

Removing the lead from the solenoid and using a 12 volt source you can energize it to see if it is operational.

If the solenoid is good and thee is no voltage there then check the relay. __ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Reply to
Randy G.

Is this automatic or manual? Assuming automatic, the relay is 95% likely to be the problem given the symptoms you're seeing. It's located behind the dash to the left of the glovebox (LHD cars) and is most easily accessed by removing the glovebox assembly. Once the relay is out, the cover can be popped off and on the circuit board you'll find cracking in the solder joints at the heavy connections, this is the problem and it's fixed by heating the joints and flowing some fresh rosin core solder into them.

Reply to
James Sweet

Look for a round single wire plug under the car, on the passenger side at the rear of the transmission. With it unplugged the transmission should shift into overdrive normally. The odds are about 3 in 10 that the solenoid is at fault. The other 70% of the time there is a problem in the valve body in the transmission, especially if the fluid hasn't been changed regularly or has gotten low. There are several nylon check balls the float up against the separator plate in the valve body that can erode away to nothing over time when the fluid is carrying a lot of metallic debris.

Bob

Reply to
User

The trans has been serviced on a regular interval but sometimes i have jiggled the wire under the trans and the overdrive works but stops working a few days later. It looks to me that the wire to the solenoid has 2 wires but looking online at the part it has only one wire. So if I do disconnect the wire that you told me to disconnect and it works than is my problem internal?

Reply to
zforce77

Yes.

Reply to
User

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