1999 Chevrolet Suburban

Electrical problem
1999 Chevy Suburban V8 Four Wheel Drive Automatic 136000 miles

1999 GMC Suburban 4WD 7.5lt
I am wiring a trailer connector. GM has two dead ended wires one dark blue for the trailer brakes and one orange to charge the trailer battery. The GM service manual shows the orange wire connecting to the under hood fuse block stud B. But the stub B is maked " flashers 30A" under the hood and there is currently nothing in it. Do I just need to plug in a 30A fuse in it and the orange wire would be hot? Is Stud B always live? This could drain the Suburban's starting battery if the trailer is connected with the engine off. How do I prevent that? Also I'd like to know how to install a second battery under the hood for trailer? Also how to activate the trailer brakes (the blue wire)? Thanks, Hide
June 4, 2009.

B cavity is designed to trailer and or camper hook up
need to have 3o A fuse to make trailer wiring alive
it should not drain the battery
all trailer lights controlled by the head light switch
as to connect a 2nd battery
and you need to have it charged by the truck alternator
this is how I would do it
negative side connected to engine ground
positive side connected to positive side of the older battery
I see no reason for another battery if you adding a trailer
you can go for a bigger battery if that make you feel better about things

good luck

Jun 5, 2009.
Okay so I plugged in a 30A fuse in the block B. The orange wire (taped to the blue electric brake wire they both appear to be 10ga wires) is still not hot.
So what gives?

Jun 7, 2009.
Step on the brake and check

Jun 7, 2009.
I am not talking about the brake light wire. I am talking about the extra 12V supply line to the trailer on 7-way plug. You should read the whole thread before you answer the question. Your last answer was almost insulting.

Please refund my donation.

Jun 7, 2009.