a while ago i posted about a problem with my 89 740 auto trans. Got good advise from you guys and the problem seemed to be the relay behind the fuse block. I didn't replace it yet, but if i just touched it, the kickdown light went off and the car shifted.

Well, now it doesn't shift into overdrive and the light is not on and touching the relay doesn't help. The fuse controlling O/D is ok. I can activate the light with the button, and make it go out touching the relay, but it won't shift. Sometimes after driving about 10 miles, then slowing down the car will mysteriously shift. Fluid level is ok also.

Got any ideas???? It's in the teens here so I'll try and do something about it when it warms up a little. Thanks

 

I would replace the relay first and then take it from there.

 

Given the description you gave regarding jiggling the relay and getting a response, I would take a very careful look at the back side of the relay board. The flow soldering done on Volvo boards is less than first rate, and the problem manifests itself particularly around large solder contacts, probably because flow soldering may not heat the contact for solid adhearance. Over time, a hairline crack may develop at that point. The result is either intermittent function, or function when the contact is under pressure (such as moving the relay around).

You really need a loupe (at least 10X) to spot this type of crack, but look closely around all of the solder points for that relay connection, and see if any seem to have a little tiny gap that literally circles the contact, rather than a smooth dome of solder with the contact point looking like it is totally enveloped. As a last ditch, if you have made the effort to get the board out, but cannot tell, consider hitting each solder point for this relay with a pencil soldering iron of 25W to 35W (max) long enough to melt the solder, then let it resolidify. This will insure that any hairline separation is sealed. Put it all back together, and see if it does not fix this problem. BTW, the same malady also accounts for A/C relays that midbehave (the A/C compressor clutch sometimes engages, sometimes not). Good luck!