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... finally got my obd2 scanner to connect and got code P0155 and a pending code P0449. Could these be the source of the bad mpg. I cleared the codes for now

Edit #3.. fooled around some more with my scanner and got some more codes that came up. The only way I can connect is if the gauges go up and gear indicator are on, when the key is only in the run pos but not after I crank it. I am having trouble figuring them out. I will leave a screenshot of what it pulled.

 

Possible ground or BCM

 

i checked the grounds i could reach, and a shop checked the hard to reach ones for free. is there any way to know for sure that my BCM is bad? And would it cause all of these problems?

 

is there a way to tell for sure before I dump hundreds of dollars for a new bcm and programming?

 

im` sure theres a way to check it but I dont know how

 

Tech 2 scanner and factory diagnosis charts. Looks like you're going to spend at least a few hundred any way that you go. Sorry, but it looks like you found out why the previous owner got rid of it. On the bright side, at least it doesn't seem to be an intermittent. Looks to me like a problem in Instrument Cluster or BCM

 

well damn. Should I just find the cheapest shop with a tech 2 to pull the exact codes for me or should I just find a remanufactured BCM and find a shop to program it and get the codes all at once? I've already pulled the cluster and resoldered all the bad joints, but when the cluster is working correctly when I get in i can see that part of the gear indicator is dimly lit. Should I just find a replacement for that as well and get the miles programmed?

I have access to alldata as well

 

Let's not jump the gun now that you have some codes and more info. Let me see what I can find.

 

None of those codes make any sense for a 2004 Blazer (as far as I can find). The B2ERR and B2TAE seems to be something only obtained using Torque. No reference to U10>D. Don't believe P0017 and P1611 are possibilities in a Blazer. Man, I have no idea...... May not want to trust Torque if it is generating these codes. Usually it is pretty good. If you have a Bluetooth OBD2 and Android, then I believe Car Gauge Pro will read all the codes including BCM codes if you go to Connect/GM/Scan All Faults. You could try clearing them and see what comes back.

 

just got off work and it has been a bitch to try and get it to connect, I was only able to do the app default scan for the DTC but still manage to get actual codes with Car Gauge Pro.