Electrical - Roof light

[MGL]

Hi guys,

I got an H2 LUX 2006 - the dealer (at my request) added the low roof light bar (4 of them - http://www.h2source.com/big_frontbar.jpg). They also added a switch on the dash board - so far so good. Now, the switch is connected to a Bosch relay (12V 20/30A # 0 332 209 150- http://www.tessco.com/products/displayProductInfo.do?sku=66032&eventGroup=4&event Page=1). Everytime I turn the switch on that small relay (small black box) goes crazy with a funny sound coming out of it ???? and of course the roof lights do not work ??

Any idea what it could be - replacing that $ 3 box does not work - I did that already

Many thanks for helping out.

MGL

BTW: I live in Costa Rica so going back to the dealer is not the first option I want to hear

[KenP]

Originally Posted by MGL

BTW: I live in Costa Rica so going back to the dealer is not the first option I want to hear

Damn, I was going to tell you the stupid thing is under warranty and to take it back to the dealer.

I'm not expert, by any means, in electrical, but you may want to try replacing the relay one more time followed by the switch.

Did the lights work when you got the truck?

[PARAGON]

Originally Posted by MGL

Hi guys,

I got an H2 LUX 2006 - the dealer (at my request) added the low roof light bar (4 of them - http://www.h2source.com/big_frontbar.jpg). They also added a switch on the dash board - so far so good. Now, the switch is connected to a Bosch relay (12V 20/30A # 0 332 209 150- http://www.tessco.com/products/displayProductInfo.do?sku=66032&eventGroup=4&event Page=1). Everytime I turn the switch on that small relay (small black box) goes crazy with a funny sound coming out of it ???? and of course the roof lights do not work ??

Any idea what it could be - replacing that $ 3 box does not work - I did that already

Many thanks for helping out.

MGL

BTW: I live in Costa Rica so going back to the dealer is not the first option I want to hear

relay is right under the dash under the steering wheel? that's where they normally put them.

I'm guessing it's wired incorrectly.

look at page 14 of this wiring diagram pdf from Bosch to see how it should be wired correctly.

http://www.partsexpress.com/pdf/500-001.pdf

[f5fstop]

Can't say what it is, but try this to narrow it down.
check all the connections to the switch and relay. Hard to say if the dealer wired the switch as a ground side or hot side switch, usually, the ground from terminal 85 of the relay goes to the switch, and when the switch is closed the ground circuit is closed, activating the relay. Wiring for most relays has the power coming into terminal 86 of the relay, ground on terminal 85, direct battery power on terminal 87 and power to the lights on terminal 30. So, if you jumper terminal 87 to terminal 30, and the lights come on, it is most likely the relay. Besides, relays should not buzz, they should click when activated and unclick when unactivated.

[PARAGON]

Originally Posted by f5fstop

Can't say what it is, but try this to narrow it down.
check all the connections to the switch and relay. Hard to say if the dealer wired the switch as a ground side or hot side switch, usually, the ground from terminal 85 of the relay goes to the switch, and when the switch is closed the ground circuit is closed, activating the relay. Wiring for most relays has the power coming into terminal 86 of the relay, ground on terminal 85, direct battery power on terminal 87 and power to the lights on terminal 30. So, if you jumper terminal 87 to terminal 30, and the lights come on, it is most likely the relay. Besides, relays should not buzz, they should click when activated and unclick when unactivated.

sure wish you knew a lot about the '03 H2 wiring.

I'm about to do some clipping and splicing

[f5fstop]

I have all the schematics, what do you need?

PS Your idea about an incorrect wire job on the relay is a good one. Hard to wire on incorrectly since it can blow fuses, but knowing dealers...

[HUMTECH]

Check the connector at the light bar on the roof, I think someone wired it backwards. orange wire should be inserted into socket "C", purple wire in "A", I'll bet these are backwards. Black in "B". Sockets are clearly marked A,B,C. If that is wired correctly post up and we can look for another solution.

[PARAGON]

Originally Posted by f5fstop

I have all the schematics, what do you need?

PS Your idea about an incorrect wire job on the relay is a good one. Hard to wire on incorrectly since it can blow fuses, but knowing dealers...

I have them too but when it comes to what I'm doing.....

I want another circuit.... no, actually need another circuit. It would be nice if it was a RAP circuit. So, a while back I stumbled across the fact that the Sunroof has it's own separate RAP relay circuit. I don't have a sunroof. I happen to have had a fuse in the Sunroof spot for the battery POS power in the box under the hood, so assumed I had some type of circuit for it.

I searched and searched and don't have the relay but I do have the orange power wire that comes from that sunroof fuse AND even better a nice clean ground that's separate from other grounds inside the cab AND the best... the dark blue wire that is POS voltage for RAP.

These go into a connector on one side (connector C210) but there are no orange or blue wires coming out of the corresponding side of the connector.

So, I have decided to splice into the orange and blue wires. I need a RAP circuit for my new Sirius tuner and some other things that would be nice to run relays off of it. I don't want to splice into the radio harness or anything else, especially if I have unused circuits I can use.

[H2Finally]

If you run out of clean power source inside, and need to bring power from engine compartment, it may be easier to go thru the grommet under the driver side floor, rather than the footwell wiring harness.

[MGL]

wow - amazing - thank you all for your help - I found the problem.
Been here makes me proud to be a Hummer owner.

I just can't beleive the help I got from you all - thanks again big time.

I will now come here everyday when I can to do the same.

If anyone ever comes to Costa Rica, let me know and the Hummer will pick you up at the airport

The ground was not correctly connected - that was the problem

Wish you all the best.

Michel
mgl@netaxis.ca