TCC to ecu wire goes from 12v to 3v instead of 0v

[Andersons-Speed-Shop]

Hey guys, just got my ls swap running (gen 3 5.3 4l60 in 96 swb chevy 350/4l60 truck) and I’m testing the tcc wire to insure I won’t blow up the tranny when I put the new one in, with the engine off in run position the wire is 12.4v without the brake pressed and 3v with the brake pressed, I’m under the impression that it should be 0v with the brake pressed, is my switch faulty? At 3v will it allow the lockup to disengage with the brakes applied? Sorry if this is an ignorant question I couldn’t find any info on anyone having this issue.

 

[PlayingWithTBI]

with the engine off in run position the wire is 12.4v without the brake pressed and 3v with the brake pressed, I’m under the impression that it should be 0v with the brake pressed, is my switch faulty?

Take a light or something that will give it a load, then see if it goes to zero.

 

[Erik the Awful]

The 3v you're seeing is the resistance in the circuit after the brake switch. That sounds normal. I wouldn't worry about it until it shows itself to be a problem. According to this link, you should see 12-28 ohms of resistance in the TCC solenoid.

US Shift Technical Support

This Technical Support section will help you fix problems that may arise with your transmission control system.

www.usshift.com

 

[tayto]

how are you measuring this with your DMM? are you referencing your black lead to ground then taking a measurement or are you measuring across the switch (voltage drop)?