Lights, wiring, key on, battery

[therick04pp]

Hi fellas,

I'll try and make this quick...

This summer, installed an LED light bar on my 08' H3. The harness included a relay, a power switch and in inline fuse for the battery connection. Never had a dead battery in my truck before. The first time I let my truck sit for 3 days after I installed it, I had a dead battery, jumped it, it was fine until this cold weather hit. The battery went stone dead again and even after charging, will die down pretty quick if it sits for a day. The whole unit is connected: from the battery, then through the inline fuse, through the relay, to the under dash power switch, then out to the bar. The power switch under the dash is off and has a small red LED to let me know it is off. When i turn the switch on (green LED), the bar comes on.

Could it still be draining the battery even if the switch is off? Something I noticed today. I connected a new battery charger with an ammeter on it, to the battery. When it gets to 100% charged a green charged light comes on, after about 2 seconds the needle swings down to 75% for two seconds (charged lights goes out), than back to 100% (charged light on)..2 seconds, 75%..2 seconds etc, etc. Almost with the same rhythm that the horn would go off if the anti-theft was activated. When I take out the fuse to the lights bar, it still does this. I connected a mutli-meter to the battery after a half hour of watching the needle swing, after I unhooked the charger. It started at 12.51v and I watched it steadily drop to 12.42. Every 4 seconds or so, it would drop .1%. Not sure what to think at this point. I may need a new battery regardless.

2nd thing I need some help with. Where, under the hood, is an easily accessible place to wire the lightbar, so that it will only turn on when the key is turned on. It has a fuse and relay already, just need a spot to hook it up so that it only turns on when the key is turned and if it is a battery drain issue, I can replace the battery (if needed) and not have to worry about it again.

Yes, not to brief, but I am having a few issues that all seem to be related.. Thanks for reading this far and I appreciate any help anyone can give.

 

[JPaul]

I doubt it has anything to do with the light bar, a small LED is going to take years to drain a car battery. It'd actually drain from self discharge first...

More likely is you either have a much larger parasitic drain from somewhere else (shorted wire or something) or you're battery is just going out. Might want to take it to Autozone or somewhere and have them test the battery for you.

As for wiring the lightbar easily and cleanly, you can either add on a circuit from the battery terminal, or do what I did and use the expansion plug under the fuse box: http://www.hummer4x4offroad.com/forum/showthread.php?10319-BEC-connector-(offroad-clearance-lights)

 

[therick04pp]

I doubt it has anything to do with the light bar, a small LED is going to take years to drain a car battery. It'd actually drain from self discharge first...

More likely is you either have a much larger parasitic drain from somewhere else (shorted wire or something) or you're battery is just going out. Might want to take it to Autozone or somewhere and have them test the battery for you.

As for wiring the lightbar easily and cleanly, you can either add on a circuit from the battery terminal, or do what I did and use the expansion plug under the fuse box: http://www.hummer4x4offroad.com/forum/showthread.php?10319-BEC-connector-(offroad-clearance-lights)

I thought the same thing. Its a super small LED but im hoping that somehow there isnt something inside the bar that causing the draw. Although I doubt it because it still did this even after I unplugged the fuse at the battery. I think the swinging needle on the charger, is showing me that something is continuously cycling or grounding out, causing the drain. As for hooking it up, All I need is a power source that is hot only when the key is on, located under the hood that I can tap into. The link you gave is awesome, but it's just too much for a simple keyed power source only.

 

[JPaul]

It might seem like a lot for just one thing, but it'll make adding anything else super easy. Plus for hooking up to something that is only hot when the key is on is either going to be using the expansion plug and pigtail I showed you, or having to tap into additional wiring somewhere else and potentially having issues due to exceeding amp draw for whatever circuit you tap into. I strongly recommend getting that wiring pigtail and using the seperately fused circuits already in place instead of messing around with splicing into another power source. Since I did that pigtail, I've added several other things like a backup camera and an in-cab winch control switches that only work when the key is on (to prevent the winch being actuated accidentally. I also have the spots on the winch wired through that so that they turn off when I turn off the key, preventing accidental dead batteries.

But if you really don't want to go that route, you can take a look at the schematics on http://schwarttzy.com/h3-hummer/ and try to find something useable to tap into. I just prefer it being nice and clean and nothing is cleaner than using what the factory already provided. The only thing I have wired directly to the battery are my radios, and that's because it helps reduce interference from the car's systems.

 

[650Hawk]

A fuse tap can be used in the fuseblock on either an existing fuse or a vacant fuse, and provides an additional fuse protection for the switch & relay coil. It's easy to find a hot spot with a simple 12v tester. I initially set my light bars up so that the switch powering the relay coil was only hot when the ignition was on. After a bit, I switched the fuse tap to one that was hot all the time instead. The fuse tap is shown below, although I don't remember if this pic was taken before or after I moved to an "always hot" position; both are available in the fuse block.

I'm a little confused on your wiring description, though. You should have (2) hot wires; one heavy gauge wire directly from the battery through the inline fuse to the relay (the other side of the relay then goes directly to the lightbar, also heavy gauge). A second hot wire (smaller gauge, shown in the pic above) will go from your fuse block through the switch, and then from the switch back to the relay's coil (the switch also likely has a small ground wire, for the LEDs), and of course the final side of the relay's coil goes to ground. Finally, of course, you have the ground wire from your lightbar to ground.

However, the fact that your battery still goes dead even with the inline fuse pulled suggests that your lightbar wiring is not the problem.

 

[Kyle]

how old is the battery? sounds like its going bad. id get a new battery before going further.

 

[therick04pp]

The fuse tap is exactly what I was looking for. The wiring has a Y at the bat (neg/pos) with a fuse on the hot side, both go to the relay. From the relay is two separate harnesses, one going to the switch and a second harness out to the light-bar. Just had to go check it. I do think the battery is ok, but there is something else draining it, not the bar. Either way, I still want the bar hooked up so that it only comes on when the key is on.

I did forget to mention this earlier. Just as it was getting cold out (2 months after it first went dead), my remote starter quit working for a few days. Then one day I hit it and it worked, however this time, THE KEY WOULD NOT START THE TRUCK. This went on for about 2 weeks that I could not start the truck with the key, only the remote start worked. Then, over night both the key and remote start worked again and I have not had an issue since. I think the intermittent drain (the charger ammeter needle bouncing from charged to load on batt and back) is the factory security system activated... The remote start and key start issue must have been a sign of something. I just didn't look to hard because it sorted itself out. I think ill bring it to the place that installed the remote start and have them look at the system.

 

[JPaul]

I forgot about those add-a-circuit things, I've never really liked them personally, but they're fine for adding a single circuit.

 

[therick04pp]

Thanks for the help JPaul. Hopefully I can get the bat issue sorted out painlessly... fingers crossed. Haha.

 

[alrock]

I've used fuse taps for the switched power outlets but also use the Blue Sea systems for easily controlled, but always on, power. For example, I like to be able to use my LED lights with the ignition off. I've had them on for four hours straight and still been able to start. They can help light up a Hummer repair as night sets in.

 

[rascole]

Just to echo what was already said above. Sounds like the battery is going dead or poor charge from alternator. Fuse tap/add a circuit work great.

 

[Hopkins86]

Hi fellas,

I'll try and make this quick...

This summer, installed an LED light bar on my 08' H3. The harness included a relay, a power switch and in inline fuse for the battery connection. Never had a dead battery in my truck before. The first time I let my truck sit for 3 days after I installed it, I had a dead battery, jumped it, it was fine until this cold weather hit. The battery went stone dead again and even after charging, will die down pretty quick if it sits for a day. The whole unit is connected: from the battery, then through the inline fuse, through the relay, to the under dash power switch, then out to the bar. The power switch under the dash is off and has a small red LED to let me know it is off. When i turn the switch on (green LED), the bar comes on.

Could it still be draining the battery even if the switch is off? Something I noticed today. I connected a new battery charger with an ammeter on it, to the battery. When it gets to 100% charged a green charged light comes on, after about 2 seconds the needle swings down to 75% for two seconds (charged lights goes out), than back to 100% (charged light on)..2 seconds, 75%..2 seconds etc, etc. Almost with the same rhythm that the horn would go off if the anti-theft was activated. When I take out the fuse to the lights bar, it still does this. I connected a mutli-meter to the battery after a half hour of watching the needle swing, after I unhooked the charger. It started at 12.51v and I watched it steadily drop to 12.42. Every 4 seconds or so, it would drop .1%. Not sure what to think at this point. I may need a new battery regardless.

2nd thing I need some help with. Where, under the hood, is an easily accessible place to wire the lightbar, so that it will only turn on when the key is turned on. It has a fuse and relay already, just need a spot to hook it up so that it only turns on when the key is turned and if it is a battery drain issue, I can replace the battery (if needed) and not have to worry about it again.

Yes, not to brief, but I am having a few issues that all seem to be related.. Thanks for reading this far and I appreciate any help anyone can give.

I'm not the smartest guy in the world but my sunroof leaked in to my floor and got my bcm wet and messed it up and that made my hummer eat batteries if I didn't drive it every day it was dead as a door nail I think the gym said it was pulling milla amps or something like that it took them awhile to track it down like 3 days of pulling fuses to be exact and a decent bill best of luck hope it helps


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[650Hawk]

The aftermarket remote start is a big suspect. These H3s don't play well with aftermarket alarms, remote starters, etc.

 

[therick04pp]

The aftermarket remote start is a big suspect. These H3s don't play well with aftermarket alarms, remote starters, etc.

Yeap, I agree. After the weird issue with it, this is my prime suspect. Of course I am going to wait until winter is over before getting it checked..