[rfmaster]

Originally Posted by mcbassin

RF,
You mentioned that one of the relays is for the A/C controls? Is this to kick the compressor on? I assume I will need to tie this into the truck harness?

Another thing came up today that for some reason I never noticed. This transmission has an electrical speed sensor and the truck has a mechanical cable that runs the speedo. Is there a simple solution for this? Or let me rephrase, is there a cheap solution to get the speedo to run?

We made good progress today on the install. Finished the exhaust, changed out the sending units, moved the tranny cross member, put the new straps on the rear U-joint. It looks like I will need to drill some holes for the cross member. 2 bolts on each side lined up. Also, the driveshaft seems to be just about the right length. Hopefully, we can wrap up all the mechanical this week and get to wiring this weekend. This is slow going when you only have an hour here and 2 hours there. Here are some pics:

Mike

Regarding AC control relays and circuit.
AC control circuit will require some rework. I have a FSM for '91 B-body which covers AC circuit in detail. I do not have the same manual for your truck! If you can get your truck information than we have a good chance of putting a combo harness that will work.

Regarding speedometer.

Bad news - money involved. To get a fully functional spedo - VSS will require procurement of two parts. You have to get a mechanical speedometer driven gear housing - that's what plugs into transmission in place of your electronic vehicle speed sensor (VSS) from an earlier 700R4 equipped car or truck from JY or a local tranny shop. Try to get aluminum one - they last longer. Depending on tire/rear end ratio you'll have to change driven gear to get speedometer to read correct speed. Furthermore, to keep ECM happy an inline bolt-in VSS from JTR will have to be procured. TBI equipped cars and trucks used two-pulse (2000 pulses per mile) square wave VSS (it's a reed switch) through 1992. You can read a full explanation here:
http://www.jtrpublishing.com/Pages/S...eedometer.html

A lower cost VSS is available from Summit made Rostra Precision Controls 250-4153
http://www.summitracing.com/parts/RPC-250-4153/
Specs for this part - number of pulses per revolution are not available. I did not use this part before so I have no first hand experience. Perhaps, worth a call to summit tech line.

Another rely cheap inline VSS is made by SCS/Frigette 208-3606 - again no first hand experience with this one.

More discussion with VSS retrofitting can be found here:
http://www.binderplanet.com/forums/s...ad.php?t=50649

//RF