I would like to get power from the OBDII connector.
The PIN 16 is the Battery Power, the PIN 4 is the Chassis Ground and the PIN 5 the Signal Ground.
So which PIN of the 4 (Chassis Ground) or 5 (Signal Ground) do you recommand to use with the PIN 16 (Battery Power), in order to get 12V without risk to damage the Hummer H2 or other internal equipment ?
In advance thank you very much for your help.

 

Geez - do you really want to mess with the OBDII connector at all? I mean even if you got the right PIN combo, you still have a chance of zapping some on-board computer or module or something that could cost big dollars to replace. No other "hot spot" will for your your project?

*Sorry this is not an answer

 

Thank you for your reply.
You are right, I would rather get 12V power somewhere else, but I don't know where, easily without desassembling a lot of things, in the left side of the H2 (driver).
I'm a novice in mechanical and electrical, so it should be very easy to plug... I am open for any suggestion !
In advance thank you very much.

 

What are you working on? Maybe its been done?
Do you need constant 12v or 12v when running?

 

The power is for a digital altimeter fixed on the dashboard.
If the 12v is only when running it should be perfect, but if it's constant I can install a button. I just bought an OBDII connector with power button...
If you have any suggestion for 12v on the left side instead of OBDII, or confirmation of the PINs (#4|5+16 ) to use from the OBDII connector... Thanks a lot !