Engine Rebuild and New Wiring Harness -- Transmission Problem!

I am trying to think of anything that could have changed since the rebuild. So far I can think of:

1) new wiring harness

2) I cleaned the engine compartment and might have gotten water in the tranny with the motor off. (This is a guess - not sure if this is possible

3) having the tranny dismounted from the motor and towing the vehicle mutiple times may have dislodged "stuff" in the tranny.(dirt, grime, particles?)

Why else would a tranny start slipping when it wasn't before?

Was the trans serviced in any fashion - fluid changed etc?

No. When I got the car not very long ago, it had major engine oil leaks, so we drove the car only short distances around the neighborhood. Then we pulled the engine about two months ago to put new bearings on the crankshaft.

During this time the car was towed to my house on a trailer twice, with the engine out, so I could do other work.

Finally, the engine went back in last week, with a new wiring harness. The mechanic said an oil pressure sensor was bad and no oil pressure. He replaced that and said it worked.

Next he said he thought the fuel relay was bad because he had to force starting fluid in the intake to start it - I told him there was a spare, new relay in the trunk he could try.

lastly, he said when he got the car started, the rebuilt engine ran perfectly, but every light on the dash lit up (except the oil pressure light) and the tranny slipped badly.

Thanks, JB

Service the transmission.

I can't recall if it has a filter or screen: if so, replace / clean it.

Change the fluid.

As for the lights coming on: sounds like a short somewhere: if it keeps happening, take it back to the guy, or failing that, to an auto electric shop.

(I would suggest troubleshooting the wiring yourself, but I assume you don't know how to)

Thanks, mechanic still has the car, i haven't seen it. Mechanic is a friend of a neighbor, working in his spare time as a hobby. I trust the mechanic, but he's new to Volvos, so I am trying to come up with answers to help him out. He's charging me very cheap labor, so I'm trying to help out.

I agree with the service of the tranny. but those dash lights are weird. maybe incorrect wiring harness installation?

Yes, especially if it never goes out.

Check connections near alternator, starter solenoid, and ignition.

Compare it to the wiring diagram.

"maybe incorrect wiring harness installation?"

Could be.

Have you emailed the vendor, Dave Barton?

He'll probably know.

roll dem bones

Gary/Bones: Thanks guys. I measured the radius on the harness and know about where the connector should go. Problem is I cannot locate anything to plug into. I could easily make the harness, and plug the end at the firewall into the obvious connector. But, at the other end near the starter, I would not know what to plug it into. We looked and looked - and could fine nothing.

Yes, I emailed Dave Barton and am waiting for an answer.

If the lights all come on, the alternator is not putting out juice. What shape is the brush pack in? Check the ground wire on the alternator too, and any other wiring going to it. It's part of the harness you replaced.

Thanks - will check!

Check the transmission fluid level. There may have been substantial loss if they disconnected the cooling lines. Don't know about the wiring, except that bad grounds are a common problem.

Thanks all. Fluid, filter change, check all connections.

Will do.

JB