Adding 4 LED Dome Lights Causes 20 Amp Fuse to Blow In Truck

Published 05/11/2015

Question:

I have 4 of these compartment lights wired up to a 15a fuse then to a switch going to the trailer harness. For some reason 3 lights is fine but when I hook up the fourth light and then turn the lights on it blows the main 20a fuse in the truck, completely skipping the lower amp fuse in the circuit. Could someone help me out? What size fuse should be used for 4 of these lights?

asked by: Coleman C

Expert Reply:

Even using 4 of LED light # ILL24CB would only produce about 1/2 of 1 amp. The fact that the 4th light is causing fuses to blow indicates to me that there is likely a short. Although it is weird that it doesn't blow the 15 amp fuse (unless the 15 amp is a slow-blow fuse). I would go with the smallest fuse you can get that is greater than 0.5 amps.

Check the wiring where the 4th light is installed including the ground and make sure there are no pinched or frayed wires touching bare metal or any corrosion that could cause a short. I would also go ahead and check the wiring for all of the lights and the switch for the same issues. Something is causing a spike in the power draw and once it is tracked down and repaired the problem should stop.

expert reply by: Michael H