Electrical problems galore and bad mpg
 

Okay.... recently purchased a used 2004 Chevy Blazer that has an onslaught of electrical problems. Firstly the instrument cluster, have a video to show as well, security light is constantly on, until I pull fuse 19 in IP fuse block to keep it from killing the battery. ABS, SES, LOW FUEL, AIRBAG, SEATBELT lights are on. Temperature, fuel gauge, gear indicator, high beam indicator, and parking break indicator do not work. Periodically though, this all stops when I turn the key to on, but not crank. Shortly after or even just leaving it in run position it will fail again. Neither the scanner at AutoZone nor the one I have will connect. I tried a new ignition switch but returned it shortly after installing it. Occasionally the whole cluster will flicker on and off dropping all gauges. The temperature and fuel gauge will occasionally drift up after being off like the fuse is pulled.

Second electrical issue... the only window switches that work are on the master controls, and the right rear window down also locks the doors. Tried a new replacement but that did not work either. The lockout switch is working fine. I tested it with my dmm and shorted the two wires it opens and closes.

MPG... city driving but should not be getting roughly 8mpg. When I drove it 100 miles when I purchased it back to my house it got roughly about 10-13mpg. I haven't done anything to try and fix this yet.

Edit: another eletrical issue that just came up after getting keyless entry remotes... The car no longer locks the doors by itself via entering programming mode or by pressing the lock button on the remote. I can hear a relay but no locking. Before I got the remotes I tested to see if I could still get into programming mode with all these problems and it did indeed lock and unlock the doors. But it did not do so when I programmed the remotes.

edit#2 I was finally able to scan DTC's but I have no idea where to begin with them
https://cimg6.ibsrv.net/gimg/chevrol...806e8ecc82.png

The security is probably what's killing it, I am not sure if your vehicle has a body control module, but everything I see points to that as the problem.

That is what someone had told me before, but i do not want to pay to get a new one, and to get it programmed then that not be my problem... Is there any way i can tell for sure that the BCM is my problem??

is there any way that I can, or get the BCM tested? The PO said that while driving in the rain that it had started working fine for about a week, but I've looked everywhere under the hood. I haven' found any corroded connections, broken wires, or loose connections