Well first I have a 2003 H2 Hummer 123,000 miles.

I am having a problem with a lot of stuff here. I get the "solid"security light on at the same time I get ABS, break light and t/c light and a lot of dinging. When the dinging happens sometimes it also says unknown driver and the charge gauge will drop to nothing, this will last for a bit. Then when the message says driver 1 the charge gauge reads normal. Sometimes the ABS, break, and t/c light will go off. It's all very random they come on for a second or could stay on for 20 minutes.The things i know so far is that the charge gauge and the unknown driver issue are tide together and when i get unknown driver i show no charge and when it says driver one it shows normal charge.

If the security light does not go on for a bit after starting the car the radio amp will power on but once the security light comes on the amp shuts off, radio works but with no sound. When security light is on, but amp will not turn back on if the security light goes out... it's a one time deal.
also some times after shutting off the car pull the key out and open that door the radio will stay on, it some times shuts off after a fer min or can take awhile for the radio to shut off. it's ;ike it does not see the door is open.

Here is what i have checked so far:
battery reads 12.8 volts not running, it does not have a draw ether.
when running i get 14.7 volts constant at the battery. whether the gauge on dash says charge or no charge i am still getting 14.7. but the car runs like the battery is going dead. I really see it when the dash reads no charge.

I have re-set the BCM couple times and works fine as far as the lights go for a bit but then goes wacko again. Normally after restarting the hummer.

I have checked grounds at the battery and cleaned battery terminals and still no luck.

 

I just had a similar problem with my dodge. One of the sensors for the anti lock system came loose. All hell broke out with lights I did not knew existed. Then it went into fail safe mode on four cylinders. Just a thought when you mentioned the lights on the dash.?

 

Yup, go through every damn electrical connector with a fine toothed comb. Check everything, if you can unplug things and plug them back in. Check the chassis grounds and make sure those are good. Usually it is nothing major but one damn connection somewhere causing havoc.

 

I had the same issue. Then all of the sudden it would no longer start and nothing in the h2 worked. I have a 2004 h2. I unplugged the wire pack going to the air suspension as someone else suggested. Then everything works. I am still researching what would be causing that.

 

Did you ever figure out the problem David?
my 03 h2 started doing the same thing today.

 

Hey bro, I had a plug which was throwing a misfire check engine light. It scrambled the computer. I disconnected the battery and it all went away but came back in a week. A trucker told me it is common and said to short the battery very briefly. Obviously take all the precautions. This fixed it and it has been a year or so since the problem. The plug kept giving me problems but I finally found a mechanic had left the heat shield off the plugs when he changed them.

Don Theodoro

 

I troubleshot this for 6 days. I also noticed a delay in my door locks when shifting into park. The radio harness. So one of the BCM modules is powered by the radio plug harness. It does not matter if its aftermarket radio or not. The wiring runs from behind console to steering controlls, to cluster and controlled by bcm. Having a certified audio guy hard wire the stero wires directly and eleminating the pigtail connector will solve any future problems.

 

Hi h2 community, today i finaly got rid of this big headache that i couldnt figure out, so my truck had the same issues, my dash lights would come on,my stereo would shut off,my door locks would act up.
And i notice when i got off my seat and got off my truck, it would trigger something, also it would kill my battery, so i disconnected my driver seat, and found out that was the problem, i still havent figured out why the seat connector would give me those kinds of problems, but i need to look into it. I really hope this helps anyone with those kinds of issues, cause i know how frustating it can be, good luck to everyone!!

 

2 words, CHASSIS GROUNDS. Check your braided chassis grounds make sure they are in good condition and their connection points sound! Also, battery should be closer to 13.5 for a standard flooded cell battery, 12.5 for AGM.