So, I'm pretty sure that I've seen something about this before, but I'm having a hard time finding it. Anyway, I'm having problems with my lights flickering. It's noticeable on my headlights and on my dash lights. I just did the sport headlight conversion, but the problem was happening before too, just not as noticeable. This happens at speed, so it shouldn't be the grid heaters cycling either. Any ideas?

 

Crank sensor? Short to ground?

 

possibly a weak alt?

 

Thanks for the responses guys. Going to load test the alternator today, I already looked for any rubbed wires or something, nothing so far. Is there any way to check the crank sensor? All the wires running to it look good, the gap is good also.

 

just make sure there is no wear on the sensor surface

 

Alright, the crank sensor looks good. Having a hard time testing the alternator in the truck because the grid heater keeps cycling on and off. Checked voltages during a variety of situations and have come to these observations. Voltage with the engine running at idle is about 13.9. At speed, voltage is about 14.0-14.1. When the headlights flicker, I notice voltage drop as low as 13.3, but range up to about 13.6. Voltages don't stay low, they end up coming back up in less than a second. The flickering seems to be an issue mostly while moving, and worse uphill.