740 Turbo OD Solenoid

Just got finished replacing the O/D Solenoid in my '89 740 Turbo. No change, still can't go faster than 52mph or it will go to 3K rpm's. Checked the relay (#12), and it is intact. What now? Replace the Trans. fluid filter?

Reply to
Katrina
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The wiring often fails at about the same time as the relay and/or solenoid. Check the run of wire, especially from the relay to the solenoid.

Reply to
Michael Cerkowski

And the switch on the gearlever if the arrow (light) on the instrument panel doesn't go on and off with the switch operation without relay clicking.

All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).
Reply to
Peter K L Milnes

What's wrong with it going past 3K? OD was an option in the early 240s, they could cruise all day at 70, just a bit noisy and poor fuel economy.

Is this a manual or automatic? Are you sure you're getting power to the solenoid?

Reply to
James Sweet

UPDATE 10-12-05: Halfway in to work today, the top gear kicked in! It works! Now all I need are new rear tires and the light on the dash tells me I've got a bulb out somewhere...

Reply to
Katrina

Have you resoldered the relay? If it kicked in halfway to work I suspect it'll stop working later.

Reply to
James Sweet

Boy, were you ever right! It didn't work on the way home from the office on the 12th, and it hasn't worked at all this morning, both on the 45-minute drive to drop my dog off at the Vet, and then another

45-minutes to my office. Grr...Thanks for the tip, I'll look at that relay.
Reply to
Katrina

Pull it out and pop the cover off it, look on the bottom of the circuit board, you'll almost certainly see obvious cracking in the soldering where the socket pins attach.

Reply to
James Sweet

I'm looking at the circuit board now, it's green and nothing like the orange ones I've seen posted on brickboard where they illustrate how they resoldered the joints. Most of the trails on there seem to be under the green layer and not accessible on the top. (Excuse my non-techie jargon, I'm new to the DIY car repair world but I'm really enjoying it!) Hubby looked at the circuit board and didn't notice anything out of the ordinary either. Do we just plop some more solder on top of what's there and hope for the best?

Reply to
Katrina

The green coating over the traces is called a solder mask, it prevents solder from going all over the place and keeps it right on the joints. Soldering takes some practice to do well but it's not too hard. You want to heat up the joint with the tip of the soldering iron until the existing solder liquifies, then feed in a bit of fresh solder, but not so much that it makes a big ball. If it gets out of control there's a few tricks you can use to remove the solder from a joint and start over.

Oh, make sure you use rosin core solder, the acid core stuff for plumbing will ruin it.

Reply to
James Sweet

Katrina,

if you are a novice solderer talke a look at this:

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__ __ Randy & \ \/ /alerie's \__/olvos '90 245 Estate - '93 965 Estate "Shelby" & "Kate"

Reply to
Randy G.

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