We have a 2004 Prius, and the other day neither the headlights or tail lights would come on. The indicator light on the dash would not come on either. The are back on now. They have been dimming or flashing off when going over bumps lately. We did just have work done on the HV battery. Could the issue be related to the HV battery, or is it more likely to just be a bad connection somewhere? The fuses all are fine. Help!
welcome! most likely something loose at the hybrid battery, but it could be either. you're going to need an ohm meter and schematic if you diy. the most likely culprit is a loose ground, so i would start from the hybrid battery and go from there. who installed it?
There is a local company, Hybrid Battery Experts LLC, that did the work. They seemed really reasonable to work with, and being that the car is 14 years old they charged me a rate that didn't put it out of the ball park for me. I will give them a call and see what they say, I am within the warranty period. If they don't stand by their work I will share that information too. Thanks for the response.
There are ground points located all over the car (the wiring diagram shows where); the ones the headlights depend on are several feet from the ones the taillights depend on (and several feet from the HV battery) so my suspicions wouldn't land first on them for a problem common to headlights and taillights. Nothing else in the car seems to flicker or go flaky when the headlights/taillights do? If so, I'd focus first on the +12 V side of those circuits, starting with a glance at the wiring diagram to see what connections are just upstream of both, before they go their separate ways. -Chap
The plethora of grounding points throughout the car would seem to make it unlikely that a problem at any one of them would affect both the headlights and the taillights, sitting at opposite ends of the car. There's one obvious exception, the one the 12-volt battery itself attaches to, and that would make everything flaky—the OP didn't mention the whole car going disco, just the headlights and taillights—and probably still only in IG-ON (in READY, the grounding of the converter under the hood matters more). -Chap
