03/18/2026
Old school trucker had an issue with low voltage on the dash, intermittent cluster reset when bumps are hit. Number of mods were added to this unit previously by someone else, power windows, fan over ride switch, water system, generator, and more. Sometimes the truck would not shut off with the key, fan stays engaged all the time, this thing was an electrical nightmare lots of scabbed wiring. This individual lives in this truck and lots of equipment, started underneath the hood checked alternator 14.2 volts moved ground same voltage, moved everything off cat walk and checked batteries several cables loose tightened, then found 2 ECM wires green rotted replaced ends and heat shrinked. Connected to positive on starter and tested cab ground shows good both ends, removed ECM plug 60 series both power supplies show 12.8 at rest and all 3 ground shows same. Driver moved a few items to where I could squeeze in and check fuse panel half of the power supplies show 14.2 the other half show 10.1 attempted to jump power no difference no spark indicating short. After finding damaged wires under the hood and repairing truck starts and shuts off, fan still running found that it was missing the ground, added in a ground fan quit and switch is working again, driver was happy closed bill 11pm night of the 16th next morning driver requested if I could resolve the alarm for low voltage. After locating a schematic low power wires in question come from the battery to relay then to ignition time to chase wires, wiring for hot side was great all the way up showing 14.2 volts until the fuse panel driver cleaned entire passenger side out when I open the door the truck died, tried to recrank it cranks no start. Shut door and it starts found the door to be trying to ground between door mechanism and striker left open and grabbed jumper cables and completed the circuit sure s**t. Never seen that before added in a whip truck runs with the door open now, looked at schematic more and seen there is a junction ground near ignition, located stud under several layers of flooring pieces, well it did not look healthy expected it to break when removing the nut it did not, cleaned all eyelits and floor inspected wires really good reinstalled and bam the voltage is the highest on the dash the owner has seen. Yes the cab was grounded but the instrument cluster and other dash items are grounded to the floor board. So due to a leaky windshield and time the grounds gave up. Total time 7.5 hours in a parking and teen temperatures with the wind blowing hard and a fan on top of it she was done!
