High Five H2
Well-Known Member
- Messages
- 1,627
- Location
- West Texas
Ever since I've owned my H2, it's had a slow-ish battery drain, and I'm trying to diagnose it.
Some background -
I have a theory that the alt has a bad diode and it's allowing the battery to drain, and that's why the warning light comes on. The drain is bad enough at low RPMs to trigger the light. I'm going to test it now, but if anyone has any other suggestions, I'm all ears. I also have an upgraded replacement alt so I might just put it in and check the draw.
Thanks everyone
Some background -
- The PO used it as a search and rescue truck and it had a lot of electrical stuff added on. I've taken off everything aftermarket that I could find, and there's nothing attached to the battery.
- I took a multimeter to all the fuses, inside and out, and none of them consistently show a draw.
- It's about 3 amp/hours (right?), so if I leave it for 2 weeks it will be dead.
- There's an aftermarket alarm, but turning it off or removing the fuse doesn't affect the drain.
- Occasionally, I'll get a 'service charging system soon' message and a red battery warning light. It typically comes on when I'm parked or sitting in traffic for a long time and it always goes away when I start driving.
- If I drove it frequently, I wouldn't notice the drain at all.
- I put a new battery in a few months ago and if I drive it regularly it stays charged all the way.
- Autozone tested it and said my battery and alt were both good. I don't know exactly what they test for other than total output.
I have a theory that the alt has a bad diode and it's allowing the battery to drain, and that's why the warning light comes on. The drain is bad enough at low RPMs to trigger the light. I'm going to test it now, but if anyone has any other suggestions, I'm all ears. I also have an upgraded replacement alt so I might just put it in and check the draw.
Thanks everyone