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Use your DVM and check to see what the resistance in the circuit is. High resistance = problem circuit. If very low resistance, no need to change what you have.
 

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1995 GMC Suburban
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Is this new ACDelco ESS?
 

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1995 GMC Suburban
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I think DVM is Digital Volt Meter.
I am not sure why he said you need a "voltmeter" to measure "resistance", though.

I will use Multimeter, which have almost everything.
Nowadays, everything is digital means there is no needle.
In multimeter, it usually have continuity tester also which determine if a circuit is open or closed.
 

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DVM's are digital volt meters as already described and will measure a variety of electrical measurements including resistance. Even small amounts of resistance in a circuit can cause large problems.Set the meter to ohms and see what the reading is, and keep in mind that it may show milli ohms or 1/1000 of an ohm, so you need to look at your meter to see if says ohms or milli ohms. Just knowing that a circuit is not open is often times not enough information. I recall watching a You Tube video where there were 3 solenoids in a transmission and the spec was 22.5 ohmns and one of the 3 solenoids was 25.5 and that was enough to cause major problems in the transmission. The DVM would have shown continuity, but that's not enough.
 

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Is your 92 2500 a 2wd or 4wd?
 

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Have you been able to read any codes when the SES is on? Have you tried a different TCM?
Your 92 4wd has 3 speed sensors, the normal 2 on the transmission and a third, the VSS on the transfer case.
The front sensor, the ISS, may turn on the SES but will not set a code. The middle sensor is the transmission output speed sensor and it will set a code. The rear sensor will set a code also.
Check the connectors and verify the wire colors.
Front sensor - GRY/RED & DK BLU/WHT
Middle sensor - PPL/WHT & LT GRN/BLK
Rear sensor - LT BLU & DK GRN/YEL
The 2 sensors on the trans are the same, the transfer case sensor is different.
FYI - 1994 and up 4WD do not have the middle sensor, the TCM got smarter.
Also, it is possible for the terminals in the connectors to "push back" when connected so they are just touching so you get erratic function.
Does the speedo work?
 

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We changed the input speed sensor and the light is still on. The TCM was rebuilt is what the company said when they shipped it back to us. Sometimes the light is off and everything is fine but not for long then the light is on and back to first gear no overdrive.
 
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