Hello I have been having problems with the lights in my pillar gauges blowing and I'm plumb out of ideas of why it might be happening. The gauges in question are 3 Autometer cobalts with LED lighting. All 3 of the hot wires coming out of the gauges are Y'd into 1 hot wire that goes into the light switch. All 3 grounds are Y'd together into one as well. I had the first set of gauges in (same kind) for a week and the pyro and fuel pressure gauge lights both blew out. The gauges still worked as they should other than the dead lights. The boost gauge was never effected. I sent them back to autometer and they said I was the first one they've ever heard that had the LED lights blow and I was sent two new gauges in replacement. I hooked them up and the second time i started the truck with the new gauges in the light in the fuel pressure gauge blew. I then got my meter and tested the voltage coming up the hot wire to the light in each gauge. They all read 13.6 until the grid heater kicked in then they go down to 0 volts, then come back up to 13.6. So somehow even though all 3 gauges have the same voltage and use the same circuit, it is only blowing one at a time. If anybody has any idea whatsoever of why these lights might be blowing I am open to suggestions. Grid heater spiking maybe? I don't know

 

Wiring them directly to the light switch was a mistake. Your truck has no headlamp relay (unless you drive a 3500 that was retrofitted with an overlay relay as per Chrysler recall #819 or820, iirc), so the switch carries the entire load. It's about maxed out as it is. Anything, and I mean anything, even a few small LEDs, added to that switch can cause problems like blowing fuses or worse, melting the harness.

Your best bet is to run your gauge power to the switched 12v cigar lighter wiring, as it can take a good sight more load than it carries, and wire the gauge lights into the radio dimmer (it's orange on a 2nd gen, I think). You should be gtg, then.

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I just read your signature, so disregard the bit about the recall. Even though you have the exact same switch/wiring as the 3500, your truck wasn't subject to it.