Electrical Shorts & Limp Mode

[heyitzjoel]

Good afternoon yall, I'm having an issue with my 1998 Chevy K1500 A/T that I've been trying to solve for a while now that is causing my work truck to go into limp mode and also gives me intermittent codes. I went ahead and disconnected the battery aslong as most of the wire harness and took resistance readings of all the VCM wires to ground. All of my pink wires in the engine bay resistance to ground were reading 38-40Ω. My IGN-E, ECM-1, ENG-1 were all also reading the same exact thing. I went ahead and started pulling and replacing fuses to isolate where this was coming from until I pulled the "gauges" Fuse 4 in the IP fuse box. Once this fuse was pulled my pink wires were no longer reading 38-40Ω. So now I know my short is probably coming from something connected to this fuse which connects directly to the instrument cluster. I disconnected the ignition switch, still reading 38-40Ω at the Gauges fuse.

Is there a ground in my dash for the instrument cluster? Could it possibly be my fuel pump & sender being improperly grounded? Should I replace my instrument cluster?

The BRWN/WHT that connects MIL to the instrument cluster to the VCM is reading 58Ω.
The TAN wire that connects my oil pressure sensor to the Instrument cluster reads 72Ω.

 

[xXxPARAGONxXx]

I would have checked the DTCs before disconnecting battery.

 

[heyitzjoel]

I probably replaced every sensor that gave me a code in the engine bay about 2 to 3 times and received the same exact codes before realizing this is an electrical short somewhere and testing wires. Alternator and battery are also both new. The only thing that I could think of that would be affecting everything would be that fuse for the gauges since it’s giving me such a high resistance reading, and when I plug it in all the other fuses in the instrument panel connected to Fuse 4 short out as well as the IGN-E & ECM-1 Fuses in the engine bay fuse panel. All the grounds straps are brand new and so are the battery cables.

 

[heyitzjoel]

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Here's a better diagram that I found online which shows more things the Gauges fuse connects to. The PRNDL and Trans fuse will show 38-40Ω to ground if the GAUGES #4 fuse is connected. So this is how I know it something that connects specifically the the GAUGES #4 fuse. I'm assuming its the fuel pump & sensor or maybe a faulty ground at the fuel pump? Could this cause the fuse to have a high resistance? My fuel gauge also isn't very accurate at all.

This is also what I found online:

For single fuel tank vehicles, the fuel gauge includes the following functions:

• The level sensor in the fuel gauge sender produces a resistance of about 40 ohms (Gas)/0 ohms (Diesel) empty and about 250 ohms (Gas)/90 ohms (Diesel) full.
• A short to ground in the sender or the wiring provides a fully empty indication.
• An open in the circuit provides completely full indication.

Right now my gas tank is empty from troubleshooting this darn truck in my driveway for the past month, so I'm assuming this resistance reading is coming from the fuel gauge sender? Is it possibly not grounded?