Electrical Issue 2004 Tahoe Z71

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bandroidx

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Hi all, I am having an electricla issue with my new to me 2004 Tahoe Z71 v8 5.3L. 152k miles.

It started the day I had to replace my water pump, when I started the truck that day I got garbled text on the lcd display on the dash where it says driver 1, etc. After driving for about 30 seconds it cleared up.

Later that day the truck over heated and it turned out my coolant was gone and me and a friend replaced the water pump which was leaking full blast from the weep hole. (I am including this water pump detail since its so close to the problem starting and i am thinking perhaps the leaking coolant got into a connector?) the coolant was sprayed all over my engine ccomparent ment too from the fan spraying it i guess.

Next day truck is running great but the radio doesnt turn on when I turn on the truck. Its like the radio is dead. Then about a minute or so later the radio turns on and is fine. This continues randomy for about a week, sometimes the radio turns on right away and then sometimes it take a minute to power up and then runs fine.

Today, I go to start the truck and it doesnt want to start like the battery is dead, oddly after cranking really slowly, it starts up. However, all my guages are dead. BAttery charge guage, fuel guage, etc. Battery light is on, I think the ABs light was on. I turned it off, it started right back up but same issue. Next I hear bass coming but no audio, turns out my radio is on, which turned on my amp and the sub is the only thing working as i assume the bose factory amp is not turned on so it cant power the regular speakers. I also notice that the AC light is on, even though the climate system screen is off which is also odd.

At this point the truck wont start again and I check and the battery is at 5.9V. I put on my lipo jump pack but its half dead and cant crank over the engine however i notice with the lipo pack connected to the battery all the guages turn on properly on the dash.

So I pulled the battery which is now at the battery store who are charging it for me overnight and then going to test it tomorrow but I dont think the problem is the battery, not the original problem at least. I think the battery was drained by what was causing the other gremlins.

The following things have crossed my mind based on my own thoughts and googling:

  1. When the coolant leaked from the waterpump it got in to the ECU connector, I dont know where the ECU is but i have read people saying htey have similiar issues and it was from liquid getting in to the ECU connector or from the ECU connector being oxidized. plus when we replaced the water pump we thouroughly washed out the engine comparent with a hose to get rid of all the coolant so everything in there got really wet. my friend however says the ecu connector is a monster, has mega seals and is highly unlikely anytrhing got in it. he also is afraid to remove it as he says if the connecdtor gets messed up removing it the truck is basically trash.
  2. The body control module is bad? The fact the radio would turn on 1 min after the truck points somewhat to the BCM. It controls the power of the radio (keeps it on until you open the door) plus the BCM is maybe controls the LCD screen on the dash where i saw the garbled text originally.
  3. My remote start has a short or bad relay. I have a high end viper 2-way but ive seen them die before and cause all sorts of issues. maybe its shorting out a accessory or 2nd ignition wire?
  4. The radio is broken and causing some kind of short randomly or is staying on always using the +12v but i doint know if this is even possible. Also i have a factory amp conversion kit, the blue box i forget who maeks it that integrates the factory amp and steering wheel controls to the radio. maybe this box is broken and causing the radio turn on issue and also is staying energized when the truck is off?

Yeah this is a pickle. Looking for advice and where to start, do any of these 4 make more sense than the others? Hell my friend thinks it could even be a bad LED headlight or fog but i doubt that,.

THANKS!

 
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bandroidx

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I understand since it has electrical in the title my post was moved to the audio and electronics section but this post is not really an audio and electronics question. my truck is broken. my concern is i get no help because its been moved to this less viewed seection,
 
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bandroidx

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I live in NJ, ive never heard of a tech2 is that a special kind of scanner?
 

swathdiver

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We should have a map or something where members can put which city they live if they wish to get with other members. In situations like this it would be most helpful for folks.
 

MCAT069

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Check your grounds. Do you have any codes associated with these issues?
 
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bandroidx

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grounds look all ok. we put the battery back in today and it was weird at first. door locks didnt work, engine started and died 5 times in a row. disconnecting the battery again and reconnected it and everything worked perfectly. no issues. then, we put an amp meter on it, 2.5amps when the door is open and lights is on. close the door and wait for liights to turn off - 1.5amps. wait about 30 more seconds and it drops to 0.02amps, so it seems its ok and no draw at the moment but who knows what will happen in the next week or so.

one thing we did find was a broken LED fog light that was flickering and hanging in the light. maybe this broken light was sending some kind of stray voltage in to the system and causing crazy issues?

Also no codes
 
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swathdiver

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

M1Gunner

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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!
 
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