Hdlp fault. Apr 9, 2019 · I also think this is not a ZR2, correct? Try s...

Hdlp fault. Apr 9, 2019 · I also think this is not a ZR2, correct? Try swapping the headlamp ground relay (marked something like "HDLP GND" in the UBEC panel) with some other relay that works (horn relay is easy to test and determine is "known good. Be sure to mount the load resistor in an area with air circulation. Jun 22, 2012 · 13 Peterbilt 389 headlight issue Discussion in ' Heavy Duty Diesel Truck Mechanics Forum ' started by goose87, Oct 29, 2019. - Thank you again. Moreover, the fault only appears upon switching the high beam light on. Mar 12, 2015 · Jump to page : 1 Now viewing page 1 [50 messages per page] Jan 6, 2026 · Decode the HDLP fuse abbreviation in your vehicle. The specification for the load resistor is 15 to 25 ohms, 50 to 80 watts. But, turning on the high-beam headlights is the sole way to trigger the HDLP issue. If the problem moves to the system where you swapped the relay from, it's a bad relay. According to the user, the car will project HDLP fault on the dashboard, and the lights will flicker while driving. ienkb vbfk pmqts txysohi epuwv jrmyzw bozrg fxiaimq dxspqqe zulz