Hoping someone might have some ideas, as I'm baffled on what is going on.

Background: 2007 Hummer H3, found that fuel pump relay 66 was corroded and a pin broken off inside the board. I pulled the board out and tried everything to get the pin out with zero luck. Therefore, I went and ordered the following: Hummer GM OEM 2007 H3 3.7L-L5-Fuse Box-Fuse & Relay Box 25796965. Arrived earlier this week, and I installed the new box, reattached all connectors, put the battery cables back on. Went to turn on the vehicle, with no lights, no bells, no inside lights, etc. Thus the key got stuck inside the ignition. I've pulled the upper portion of the console to detach the component that holds the key in place - key is taken out.

I've checked the voltage across the battery, measures 12.45v. Measured the voltage from the aux pins to battery, seen 12.3v. I've checked all fused and they are good to go. Here is where i'm baffled, one minute I can hit the fog lights and they come on. Turn on the headlights they will turn on, and high beams work. All the while zero lights on Instrument panel, no radio. Key on, turn over, nothing. Oddly enough the horn works as well.

I could go out to the truck right now and sometimes the lights will work and other times nothing. So damn baffled at this!

Remind you, I only changed out the fuse box - did nothing else to the truck! HELP!!

 

 

Watched this video, went out and still had same issue. Therefore, I took the two connectors in the bottom of the fuse box and connected them first. This way knew they snapped in place, then connected the top two connectors and the aux wires. BINGO!

HUGE thank you for sending this video to give me some more information on fixing this. Now lets hope this new fuse box solves some of the electrical issues.

 

That is the way to properly connect the fuse block to the two harness connecters. Trying to snap the block down onto the fuse box Tray and hop the two connectors find their way home is almost never going to work. Nice job.

Thanks ummerz.

 

Just a question: I seen tons of posts about the Engine Fuse Box Replacement on H3, some say used some say new. With used, would it not be at risk with old vehicle problems and I’m assuming brand new oem replacement is better way to go? About to replace mine and really looking for sound advise.

 

there is always a risk with used. but new will most likely be old stock so. i guess it depends on if you can get your money back or a replacement. usually there are no returns on electrical.

 

Thanx BXTek.. As you mentioned “old stock” , would probably be the safest way to go being New to use.

 

I felt it was better to get a new one then used. Wasn't sure if the used one would also have issues, and it was more piece of mind.

 

Thank you for the input. Was kinda in the same mind frame. think i will go new and leave it at that. oem of course.