I have a Vermeer RT650 trencher, that the other morning I moved, and then later in the day I went to start it, and I turn the key on and there's no power to the black control module, the fuse doesn't have power going to it, the green LED's on the module don't light up. The warning lights on the dash don't get power either. I've checked the ignition switch and it has power with key on, the power does not get to the module. There is two what appears to be inline fuses? in orange silicone on the power wires, but there's continuity on both ends. I have continuity from the ground wires to the frame. I'm considering getting a fuse tap, and then running a new power wire from the ignition switch to the fuse on the black module itself incase there's a wire that is broken in the loom. I have also changed all the relays behind the dash, switched them around. There is power going to the thick orange wire, but the pink wires don't have power at the warning light cluster. The breaker on the frame has 12v on both sides, the one by the starter. The ignition switch functions key off and key on. I have tried a new fuse in the control module. There is a larger connector, and a smaller 4 wire connector that plug into the back side of the warning light cluster on the dash. The pink wire on the 4 wire connector does not get 12v power when I turn the key on. But the analog gauges do get power.
I wouldn’t run a new power wire to the control module yet. Since the black module and warning-light cluster both lost power, but the analog gauges still work, the problem is more likely in the shared switched-power circuit between the ignition switch and those components. You already have 12V on the heavy orange wire, so I’d check the relay socket itself, not just the relay. Verify: battery power into the relay key-on signal to the relay coil relay ground switched power coming out to the pink wire Also use a test light, not just continuity. A damaged or corroded wire can show continuity with a meter but still fail under load. I’d also inspect the relay sockets and harness connectors for loose, pushed-back or burned terminals, especially since the machine worked earlier that same day. The dead pink wire is probably a symptom of an upstream fault. Find where power stops before adding a bypass wire, because jumping directly from the ignition switch could bypass a relay or back-feed another circuit.
Just an update, I got a new test light with an audible speaker thing. That made it easy. Traced the pink wire from the ignition switch, followed it into the loom, cut the loom open which I didn't want to do. but I was done messing around. Found a junction with 3 wires, cut open the heat shrink, pulled on the shrink to get it off, and the wire broke. I figured that must've been the issue, so I clamped it back together to test it this time. And nothing, no change. So I basically cut the whole loom open, tracing that pink wire, it went toward the injection pump side, there was two open spots on one of the wires. Which were wet inside the electrical tape. No idea why. There was no changes with anything I did. But then I found behind the turbo, between the block, and the turbo. Wires were melted. Like there was previously a small fire or something. The insulation was cracked and the copper wires were exposed. I moved the wires inspecting them, and then peeled the wires apart from each other, and then went back and turned the key. Nothing. Farted around with a bunch of wires, moral was low, I flicked the switch on the backhoe controls and noticed that the switch was in the off position. Put it to run. Sure enough when I turned the key back on the warning light cluster lit up. Machine started right up. So I spent the afternoon, cutting old wires out, fixing exposed copper, peeling off old electrical tape. Cutting, soldering, heat shrinking connections. I just need to put the loom back together. So if anyone is reading this having the same issues. Go into your engine compartment, check the two wires in a small loom that are between the turbo and the engine block. That's where I found my issue in my wiring.