Newbie here. Just bought a 1999 H1 a few months ago and I'm having issues with a draw on the batteries which kills them in like three to four days. I've searched the forum and didn't find any post with similar issues and was hoping you guys might be able to help.

Took the H1 to my local Hummer mechanic and he did a leech test which resulted him finding a draw. He started pulling fuses until he pulled all of them but wasn't able to find the draw. Once he reconnected everything there wasn't a draw right away. Seems like it's back because the batteries have died twice since then. I've unplugged almost every accessory the truck has trying to pinpoint the issue (radio, cd changer, brake controller, XM radio, auxiliary displays, etc.

Is there anything else I'm overlooking that I should be checking?

Thanks for all the replies in advance.

Cheers,
Steve

 

Hey. I am also a relatively new owner. I have a 2000 Wagon that I purchased about 6 months back. I have the same issue. Because I had the same issue on a Z06 Corvette, I installed a Battery Tender and just plug that in every few days. Problem solved. Also, I have my truck over at Predator doing a Duramax swap. They sell a really cool BatteryTender kit for the H1. That's a pretty good indication we are not alone…

 

Intermittent short or grounding problem?

 

Thanks for the insight I took your advice and installed a battery tender under the hood last night to keep the batteries fresh when parked in the garage. Hopefully that will remedy the issue until I can figure out what the problem is. If you don't mind me asking how much does that duramax swap cost? I'm very interested.

 

The more I diagnose the issue the more I think it's a grounding issue. Now it's just the process of elimination to find out what it is.

 

A swap runs about $35k and up assuming you are doing the engine, tranny and transfer case. Predator is very cool because they do absolutely everything, test it all and warranty their work. When done, it looks like a brand spankin' new drivetrain was installed. I was able to watch most of the grunt work on my swap. There was a lot of custom fabrication involved and things like the exhaust were just works of art. The swap starts getting more expensive when you add in other "must haves" related to the increased power, etc. For example, I was told not to consider doing it w/out swapping to larger brakes. Then there are things like larger half-shafts, bio-diesel fuel lines, etc.

If you are at all interested, I recommend calling Predator and discussing. Let them know that the guy with the grey LineX truck recommended you call….

 

Where are you located?

95% of the time a power draw in a Hummer is a car alarm. Adding an aftermakret car alarm is the worth thing anyone could ever do to this vehicle.
4% of the time it's another aftermarket accessory.

 

To do a Duramax conversion right you should change out frame rails, drive shafts, half shafts, hub gears........gets expensive.

 

+Brakes

 

This went from a battery draw thread to a duramax conversion conversation. The only reason you should ever even think of putting a duramax in a hummer is if you have a 2006 ( if the old one blew up and you install the correct one from AMG) peoiod. The version of the duramax some folfks put in hummers is not the same as the alpha duramax. If you're thinking about doing a Duramax conversion to any other year you be better off burying your head in the sand. Not only does the engine not fit but then the electrical wiring harness is hacked apart. If you are thinking aboyt a engine conversion look into the Big Dog Offroad Cummins & Allison conversion kit. They finally just released the kit this week. The reason big dog and rubber dog don't do Duramax conversions is they don't do junk work and put out junk trucks. Doing the Duramax conversion to your truck is the fastest way to lower the value- anyone who know anything about humers won't even think about buying a duramax conversion truck!