Electrical Issue 2004 Tahoe Z71

[bandroidx]

What are the conditions of the negative and positive battery cables? Not just at the terminal but all the way to their terminus?

they look excellent the whole engine compartment is suprisingly clean for a 13yo car.

 

[bandroidx]

My opinion... you had multiple small issues that seemed like they may have been something bigger.
You radio for instance could probably just be your amp alone. Mine did that extremely randomly for about a year before I replaced it.
The gauges and displays being jumbled is probably just a cause of the bad battery.
After getting the battery back in you anti theft sounds like it was doing its job. Which would allow your truck to start and then kill the injectors and shut the engine off. Something you may have done since the door locks weren't functioning properly yet. Then once you disconnected and reconnected the battery it reset the issue.

Your draw is perfectly normal and as for the fog light if it's a cheapo they'll over heat and melt their own housings but as far as it causing issues through its circuit is kinda iffy.

I have an 04 z 5.3 flex and have had this thing sunk in mud. If I gave you specifics you probably wouldn't believe me but just hosing down your engine bay SHOULD not be of any issue.

Keep us posted brother!

that is exactly what my friend said when i said maybe some fluid got in to the ecu connecotrs, that he had his way deep in mud and water and never had an issue as they are sealed well. well lets see what happens, it could be multiple issues as you said.

one thing i still think could be the issue is the body control module, i just am not sure if the body control module controls what is shown on the dash screen, anyone can confirm waht controls the dash screen?

 

[bandroidx]

bad news, today i got in the truck and the guages were all dead, the entire dash was dead, all the lights, all the guages. i drove like about a minute and then the dash booted up normally, did its normal boot procedure and everything was working. anyone know what controls the dash turning on? is it the body control module?

 

[bandroidx]

Based on all these random issues I am starting to think the body control module is faulty however I just found out you have to have a damn dealer program the new one? That really sucks.

 

[HiHoeSilver]

Check grounds /connections at harnesses before jumping...

 

[M1Gunner]

Remove the cluster and check the terminals on the harness side. Make sure they're all tight, theres threads on here about opening the cluster and cleaning the internals, it's not difficult at all. I would recommend doing so and once that is complete, the terminals are verified tight and secured, spread some die electric grease into the harness side and reinstall.

Also, verify you have a good ground at G203 which is near the left A pillar which grounds the cluster.

One other thing, how's your ignition switch? Original? Loose?

 

[M1Gunner]

Also looking at schematics... looks like the only thing the BCM is going to be involved with, cluster wise, is the gauge illumination not operation.

 

[bandroidx]

Also looking at schematics... looks like the only thing the BCM is going to be involved with, cluster wise, is the gauge illumination not operation.

View attachment 183517

yeah but will it operate if its not getting power from the BCM?

 

[bandroidx]

Remove the cluster and check the terminals on the harness side. Make sure they're all tight, theres threads on here about opening the cluster and cleaning the internals, it's not difficult at all. I would recommend doing so and once that is complete, the terminals are verified tight and secured, spread some die electric grease into the harness side and reinstall.

Also, verify you have a good ground at G203 which is near the left A pillar which grounds the cluster.

One other thing, how's your ignition switch? Original? Loose?

original afaik, looks original. not loose. thing is, its not just the instruments, its also the radio not turning on randomly for the first minute of run time. also something killed the battery. also the garbled text on the screen. also the security system killing the system the first time we tried to start it 5 times after a battery replacement. also, when i keyless entry open the car, it randomly doesnt unlock the doors even though it double beeps, sometimes i have to hit unlock 3-4 times before it unlocks all the doors. its just so many issues.

 

[bandroidx]

my friends brother in law who worked for GM is saying to do the following in this order and test after each:

1. replace the key (I dont think its the key but idk)
2. disconnect the after market radio
3. disconnect the remote start and remote start bypass module
4. disconnect any other after market accessories
5. replace key clinder reader
6. replace BCM

thoughts?