I have a 93 GMC Suburban with dual heat/air. Also upgraded OEM sound system with 6 speakers and graphic equalizer and tape deck. (All Factory Eq)
Initially the short was drawing about 275 ma with everything off. Started unplugging fuses and when I unplugged CTSY fuse (courtesy lights) and the drain on battery dropped to 30 ma.
I noticed the graphic equalizer still had lights on and it felt much warmer than anything else so I unplugged it. The drain went down to 185 ma, still too much. I found the amplifier for the rear side door speakers under the drivers seat, unplugged it and the drain on the batter went down to 155 ma.
I found a CTSY schematic for a 1999 GMC Yukon that I hoped was close. I have unplugged the cigarette lights, lighted vanity mirrors and door switches, with no improvement.
I just want to sell this vehicle, it's from Illinois and rusted very bad. Anything I do is not going to improve the selling price by much, it's only worth less than a $1000. But I hate to sell it someone when it wont even keep the battery charged. Guess I could just leave the CTSY fuse out and tell them why.
Any ideas where to look?
Does anyone have a better schematic? Maybe with the equalizer and tape deck shown.
SCHEMATIC