Even more overdrive problems

[EarlKann]

Alright guys, I am quickly reaching the end of my rope here. When I first got the crew conversion running it seemed fine, but then about two weeks ago it started with the dropping out of overdrive on the freeway. Since then I have searched the board and tried everything that I could find related to this problem. Here is the rundown of what I’ve done so far.

Adjusted the TPS. Initial check found the voltage a bit low 0.55@idle. I adjusted it up to 0.65 and test drove [no change] and again up to 0.96 The shift rpm’s seemed better but still dropped out of overdrive. Went to a friends and swapped out the TPS for another one off of one of his trucks [one that I know works] Installed at 0.68V at idle and test drove, no change again. Both TPS sensors were reading above 3.2V at WOT when adjusted to 0.6X at idle, so I re-adjusted to 0.36V at idle in order to get the WOT reading down to about 2.76V, still no change [this is the current setting still].

Replaced the VSS. This seemed to fix the bouncy speedometer problem I was also having, but in the process I broke the little gear ratio adapter thingy so now my speedo reads slower than the actual speed.

Cleaned and greased every electrical connector that I could find with electrical contact cleaner and dielectric grease. Even fooled with most of the connectors to make them a bit tighter where I could. Cleaning the connector at the trans temp switch seemed to make a difference for about 20-minutes, then it came back. Went ahead and replaced the Trans Temp Switch, still no change.

Dropped the trans pan and inspected for loose bolts/damage/etc. Found nothing, replaced trans filter and fluid.

Spliced in a toggle switch to ground in the overdrive solenoid wiring. Flipping the switch while driving engages the overdrive and eliminates the problem, otherwise it still happens, so it must be something electrical…right??

At this point I am a bit frustrated with the whole thing so I have walked away and left it sitting in the driveway for a few days while I cool off.

There are a couple of things that I have though of that could be wrong, but I don’t know if they would be related to this. #1, when I put the truck together I adjusted the TV cable the way I thought that it should go [found on here 0.18 gap]. But I don’t have a factory service manual so I wonder if I did this right. Anyone have the correct procedure for adjusting the TV cable that they would care to post??

Also, #2, the 10amp fuse for the dash lights is blown, and blows immediately if you try to install a new one. Don’t know the reason for this or if it could be related to the OD problem.

Any suggestions are appreciated. I intend to keep working at figuring it out myself, but I’d also like to know if anyone knows of any shops in or near the SoCal inland empire area [Riverside / San Bernardino] that are good. I don’t want to go to Bellflower, and I don’t want to deal with someplace that will say “you need a new TPS” only to find out $200 later that the TPS wasn’t the problem.

Thanks in advance,

Donald