Technically a Tech I or II scan tool should be used. Being that they run around $5,500 you might want to call some shops. If your running a stock chip then I'd say take to your local GM dealer.

 

Try Swedeburb's GMTDScan Tech for your 1994. Works great!

http://www.enghmotors.com

 

Tech Scan Tool

The GMTD Engh site does look like it has a good, inexpensive tool. Thanks for the info.

 

Welcome to this forum, John...............

GMTDScanTech is the pcware scantool of choice - does everything the Tech1 does in the service bay at your friendly dealership.

Do a search here for local input and results.

Glow system function will resume after you get the engine up and running - takes a START or two after batteries are connected.

 

Glow plugs inop

I jumped across the power lugs of the GP relay and was able to start the engine with them but after three starts this way still have no normal GP operation. I'm going to replace the ground "C" pin with a new wire, the relay power wire (pin "B" which supplies 12 volts from the PCM) with a switched 12v circuit controlled from inside cab. Not sure of the purpose of pin "A" except that it ties in with the fuel filter, anybody no more about this part of the GP relay circuit?
I e-mailed Engh motors but haven't heard back yet. May give them a call tonight (probably ~12 hours ahead of me).

 

That is switched +12v from the GAGES fuse for the controller circuit, also goes to the WIF and heater in the fuel filter cannister - see if you have Ign power on that pin, John

 

I'll check the pins as you recommended. I may just create 12 v switched circuits for Pins A and B and a new ground circuit for C until I can figure out what is wrong with the automated OEM one. (May not get it done till Monday since I work Fri, Sat, Sun nights and will be knocking off to get some sleep soon. Thanks for the help!)