Funky Ignition Wiring repair

[Ottosdually]

I just joined this forum and I hope some one out there could help with my problem.

 

I have an 89 GMC dually with dual tanks and a 454 Big block.

 

Initially when the truck was given to me, by my father in law, the tank selector was not working but the truck ran fine. After driving it the day before the next day the truck would not start. since I am a contractor my time and expertise did not allow me to attempt to fix it. So I had the truck towed to a shop that was able to fix the switch issue and was able to get the truck started. apparently an issue with the factory alarm system.

 

They however were unable to shut the truck off with the key. The way the truck was returned was with a caveat that the way to shut the truck down was to put the tank switch in a neutral position to stop the fuel pump.

 

The manual that i have does not so wiring with the dual tank switch. I think the problem is in the ignition wiring but I don't want to start ripping apart the whole truck if there is a relatively easy fix.

 

If anyone has any words of wisdom I would greatly appreciate the help, Thank you.

[redhot1.4]

This forum is pretty dead man

But if you say it's because of alarm system. I would take it to a place that installs alarms. I had an issue with a car a few yrs back , that solved all my problems

 

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[Ottosdually]

thanks