Electrical problem ... partial

Homeboy

Original poster
Member
Jul 23, 2012
10
I have a Electrical problem that is driving me crazy with my 2004 5.3L EXT Trailblazer
Sitting in parking lot listening to the radio with engine off and all of a sudden everything goes dead.
Thinking it just timed out, I start the truck and all my gauges are dead, including the radio, fuel gauge, temp, pressure gauges, all the service lights are light up in the dash, front windows won't work, door chime dead, but sunroof works, backwindows work and the truck runs fine. Lights and everything works fine. Thinking it might be the battery and after looking at the date sticker, I replaced it with a new one ... it was due. I replaced the battery at Advance Auto and still no improvement. I had the guys check the generator, and they also checked all the fuses in the engine compartment and under rear seat ... everything is fine.
I don't want to take it to the "Stealer" and open my wallet .... Help ... Any Ideas ?
 

Sparky

Member
Dec 4, 2011
12,927
Going to shoot from the hip and say the ignition switch just went weirdo on you. Seems that most of the time when there are really bizarre electrical issues it is that switch more often than not. Cheap and fairly easy to replace.
 

Homeboy

Original poster
Member
Jul 23, 2012
10
Sparky said:
Going to shoot from the hip and say the ignition switch just went weirdo on you. Seems that most of the time when there are really bizarre electrical issues it is that switch more often than not. Cheap and fairly easy to replace.

I found one at Advance ... It looks like a plug-in module. BWD Ignition Starter Switch, CS643 $40.09
If no other posts come in today ... I'll pick one up on the way home tonight and give it a try ... Thanks
 

The_Roadie

Lifetime VIP Donor
Member
Nov 19, 2011
9,957
Portland, OR
And of course those symptoms also suggest a dead or poorly-connected megafuse, which is impossible to check out visually. Only a meter will do.
 

Homeboy

Original poster
Member
Jul 23, 2012
10
the roadie said:
And of course those symptoms also suggest a dead or poorly-connected megafuse, which is impossible to check out visually. Only a meter will do.

I checked connection and I checked power .... I had power at both sides of the megafuse, so continuity is good
 

Homeboy

Original poster
Member
Jul 23, 2012
10
Homeboy said:
I checked connection and I checked power .... I had power at both sides of the megafuse, so continuity is good

I replaced the Starter Ignition switch last night and it didn't help. I bought the Starter Ignition switch at Advance and it came in the factory box with a plastic bag that was stapled shut. It looked good, but I was expecting a sealed plastic bag that once it's open, it's yours. Do you think the part is "used" ... someone returned it ? Anyone have the same experience ? I'm not sure if I should try another switch or not
I'm grabbing at straws here, since the last thing I want to do is to take it to the dealer and open my wallet

So far: Replaced battery, checked Megafuse, checked all fuses, checked ground at passenger trany tunnel
Funny thing last night as I went to start it, the battery was 90% drained, so I had to use my portable jump start to start it.
I ran the truck for a few minutes and the battery took a charge again ... shut it off and started back up a few times with no problem.
My "running" dash lights would not go out, so I had to disconnect the battery ... that might be the same thing that drained it the night before. It was daylight out before, so maybe I just didn't notice the lights being on ... maybe a short some where ?

Truck fires up, but all my gauges are dead, front windows dead, security phob dead, door chimes dead, all service lights light up, ABS, etc

Any other thoughts would be appreciated !! Thanks
 

Wooluf1952

Member
Nov 20, 2011
2,663
Milwaukee, Wisconsin
You could go back to AA and ask to see a couple other new ignition switches. They may all be stapled.
 

Homeboy

Original poster
Member
Jul 23, 2012
10
Wooluf1952 said:
You could go back to AA and ask to see a couple other new ignition switches. They may all be stapled.

Thanks for the good idea !
Instead of going to the store, I just called Advance Auto and they had 4 on the shelf ... he went and pulled them for me and he said they were all packaged like that ... nice box & plastic bag thats just stapled shut. He ensured me that the ones he had were not returns. He had multiples so I believe him .... rats !! Well at least I know I have a new part, but my problem still isn't solved:undecided:
 

Homeboy

Original poster
Member
Jul 23, 2012
10
I talked to a Chevy dealer and they suggested that I try replacing the Starter Ignition Switch ... replaced.
Second they recommended replacing the Body Control Module ... looked at GMPartsGiant.com and part is $239.34

Has anyone replaced the Body Control Module under the rear seat with success ?
I've seen post as to how repair wiring and such, but no remove and replace
Some posts suggest that it needs to be dealer programmed, some not ... Is this true ?

Most dealers won't allow you to buy the part and have them install, so I was wondering if the juice was worth the squeeze ?
Should I bite the bullet and let the dealer help themselves to my wallet or should I attempt to swap it out on my own ?
Dealer price range was $400 to $700 ... of course depending upon what they find

Any thoughts or experiences would be welcome ... Thanks
 

Voymom

Member
Feb 3, 2012
2,523
Homeboy said:
I talked to a Chevy dealer and they suggested that I try replacing the Starter Ignition Switch ... replaced.
Second they recommended replacing the Body Control Module ... looked at GMPartsGiant.com and part is $239.34

Has anyone replaced the Body Control Module under the rear seat with success ?
I've seen post as to how repair wiring and such, but no remove and replace
Some posts suggest that it needs to be dealer programmed, some not ... Is this true ?

Most dealers won't allow you to buy the part and have them install, so I was wondering if the juice was worth the squeeze ?
Should I bite the bullet and let the dealer help themselves to my wallet or should I attempt to swap it out on my own ?
Dealer price range was $400 to $700 ... of course depending upon what they find

Any thoughts or experiences would be welcome ... Thanks

In my honest opinion...I wouldn't quite jump at the BCM right off. It is an expensive part as you can see, and if you just start grabbing at strings and guessing what MIGHT be wrong, you will be broke in no time...trust me...My Envoy gave me absolute HELL the first few months of owning it. I have had it for 8 months and have not been able to do any mods, or upgrades to it because I have been throwing money at it for maintenance since I drove it off the lot. A lot of the cash went out the window because I just decided to guess what certain issues were and replace what I "Thought" would fix the problem, instead of getting it properly diagnosed.

If I were in your shoes right now(I already kind of am) I would suggest looking for a local shop with outstanding reviews, as well as prices and go from there. I can and will be leaving my truck over night at my local shop for them to hook it up to their computers for $35.00 to diagnose a problem I have been unsuccessful at fixing for the last 8 months. Sure it's $35.00 dollars not including whatever I have to spend in parts to fix the problem, but it sure beats spending $400 on a part, then $200 on another and so forth. I would seriously recommend you take it to someone who can properly diagnose the problem.

GMTNation is slammed FULL of very intelligent and honest people, but the fact of the matter is, no one on here can see the vehicle, and witness/look at it and watch the problems first hand, so although the advice and opinions are from extremely knowledgeable and trustworthy members....sometimes it is better off admitting temporary defeat and having someone like a local shop(not dealership) look at the problem and diagnose it for you. But that's just my 2 pennies!!!
 

MAY03LT

Member
Nov 18, 2011
3,412
Homeboy said:
I talked to a Chevy dealer and they suggested that I try replacing the Starter Ignition Switch ... replaced.
Second they recommended replacing the Body Control Module ... looked at GMPartsGiant.com and part is $239.34

Suggesting part replacements without diagnostics is just retarded. Since the headlights work, the bcm is doing something.

Are you willing to do some troubleshooting with a dmm?
 

Homeboy

Original poster
Member
Jul 23, 2012
10
MAY03LT said:
Suggesting part replacements without diagnostics is just retarded. Since the headlights work, the bcm is doing something.

Are you willing to do some troubleshooting with a dmm?

I'm good with mechanicals and old school electric, but the new electronics baffle me ....
I talked to a local shop that two of my neighbors recommended and he suggested getting a diagnostic done at the dealer and go from there.
I thought it was good advice along with your thoughts above ... I need to get the truck fixed soon / car pooling with the wife doesn't work
I'm going to drop it off tonight and see what they say ... I'll keep you posted
Thanks
 

AtlWrk

Member
Dec 6, 2011
674
When you say the rear windows work do you mean with their own controls (the switch on the rear door)? Or from the front door master switch?

All of the faults you listed pertain to modules that share the common data bus wire.

There's a splice pack on top of the panel at the drivers feet (where the OBD port is). It's a small flat connector with what looks like a white plastic plug in it. Similar to the one shown in the pics here: http://gmtnation.com/f23/whats-harness-3017/ #4 in post 6.

This is the common tie-together point for all the modules' data lines. You can remove one wire at a time from this plug to try to isolate which one is responsible for corrupting the data bus. Simple 10 minute check.
 

BRomanJr

Member
Dec 9, 2011
371
AtlWrk said:
When you say the rear windows work do you mean with their own controls (the switch on the rear door)? Or from the front door master switch?

All of the faults you listed pertain to modules that share the common data bus wire.

There's a splice pack on top of the panel at the drivers feet (where the OBD port is). It's a small flat connector with what looks like a white plastic plug in it. Similar to the one shown in the pics here: http://gmtnation.com/f23/whats-harness-3017/ #4 in post 6.

This is the common tie-together point for all the modules' data lines. You can remove one wire at a time from this plug to try to isolate which one is responsible for corrupting the data bus. Simple 10 minute check.

There are actually 2 splice packs for the Data lines, the second one is located below a carpet flap near the center tunnel under the second row seating.
 

Homeboy

Original poster
Member
Jul 23, 2012
10
BRomanJr said:
There are actually 2 splice packs for the Data lines, the second one is located below a carpet flap near the center tunnel under the second row seating.

Ok thanks
The rear windows will operate from the local switch ... my driver side window controller is dead
I'll see if I can locate the splice packs tonight ..... Darn work keeps getting in the way
Thanks
 

BRomanJr

Member
Dec 9, 2011
371
Homeboy said:
Ok thanks
The rear windows will operate from the local switch ... my driver side window controller is dead
I'll see if I can locate the splice packs tonight ..... Darn work keeps getting in the way
Thanks

That symptom is enough to suspect the Driver Door Module (DDM) as the culprit. They have a large failure rate including a Recall for some years.

Lift the switch assembly out of the door panel and disconnect it from the door. Now check your other issues.
 

Homeboy

Original poster
Member
Jul 23, 2012
10
BRomanJr said:
That symptom is enough to suspect the Driver Door Module (DDM) as the culprit. They have a large failure rate including a Recall for some years.

Lift the switch assembly out of the door panel and disconnect it from the door. Now check your other issues.

____________________________________________________________________________________________
I just got the truck back from the Chevy Dealer last night
They had it for a couple days, since they had a hard time diagnosing the problem

Dealer notes:
"After running extensive Diag found battery acid or something similar in wiring connector to PCM that was keeping battery plus voltage on circuit 1049 from circuit 1589. These two circuits were being bridged by the liquid. Cleaned terminals and then addded dielectric grease to the connector. Cleared codes and retested the componenets that were not working. All working correctly at this time"

I'm not sure what "liquid" it might have been ? The battery was fine and I keep a pretty good eye on everything under the hood.
The only possible thing I can think of: ... Last Easter, with few friends and their truck, we were messing around on the beach at the "Outer Banks" and I loaded up the truck with a ton of sand. Maybe some sand got into the connectors, got wet and ? I blew everything off with compressed air when I got home ... Not sure what it could have been, but it's fixed
The bill was all labor and $20 for shop supplies, no new parts ... Total bill $407

Thanks for all of the suggested ideas guys !! This was a very unusual problem
Thanks
 

Homeboy

Original poster
Member
Jul 23, 2012
10
Thought it was done .... no such luck ... this is the third time in the last month (I've been meaning to post my last experience)
Got into the truck last Thursday to go home and the gauges all started to act funny again
Unreconized Driver, Fuel gauge, temp, pressure all go up, then down to zero, front window dead. Gauges were dead before, but now they go up for a minute or two then back down for a minute or so and over again
I shut it off and start up a couple times to see if it goes away ... nope same thing
Talked to the dealer previously and he said no drivability problems, so it's late & I need to get home, so thats what I do
Park it in the driveway. Go to get in the next day, security system is dead, get in ... truck turns over fine, but no ignition & same unreconized driver.
Call the dealer and it gets hauled back to them ... The service manager and I get to know each other.
They're one of the largest Chevy dealers / service network guys around here, so I'm getting a little fustrated that they can't help / fix the problem.
They have had the truck since last Friday morning and the service manager called this morning.
More corrosion problems, so they replaced all of the terminals computer ... not sure why they didn't do hat before ?
After they did that and ran the diagostics again, they came up with a code that one of the "Knock sensors" is bad. The one under the intake manifold.
Parts and labor is approx $500 .... :mad:
I can do mechanical work myself, but my under my current workload at work, I can't ... it' the electrical stuff that boggles me
I'm wondering if these guys are just trying to recope some of their past labor ?
Anyone have anything similar regarding the electrical propblems ? :undecided: or have had a Knock sensor go bad ?
I did a search and didn't find anything
Help ? Any thoughts anybody ?
 

dfc739

Member
Jul 29, 2012
170
Des Moines, IA
Homeboy said:
Thought it was done .... no such luck ... this is the third time in the last month (I've been meaning to post my last experience)
Got into the truck last Thursday to go home and the gauges all started to act funny again
Unreconized Driver, Fuel gauge, temp, pressure all go up, then down to zero, front window dead. Gauges were dead before, but now they go up for a minute or two then back down for a minute or so and over again
I shut it off and start up a couple times to see if it goes away ... nope same thing
Talked to the dealer previously and he said no drivability problems, so it's late & I need to get home, so thats what I do
Park it in the driveway. Go to get in the next day, security system is dead, get in ... truck turns over fine, but no ignition & same unreconized driver.
Call the dealer and it gets hauled back to them ... The service manager and I get to know each other.
They're one of the largest Chevy dealers / service network guys around here, so I'm getting a little fustrated that they can't help / fix the problem.
They have had the truck since last Friday morning and the service manager called this morning.
More corrosion problems, so they replaced all of the terminals computer ... not sure why they didn't do hat before ?
After they did that and ran the diagostics again, they came up with a code that one of the "Knock sensors" is bad. The one under the intake manifold.
Parts and labor is approx $500 .... :mad:
I can do mechanical work myself, but my under my current workload at work, I can't ... it' the electrical stuff that boggles me
I'm wondering if these guys are just trying to recope some of their past labor ?
Anyone have anything similar regarding the electrical propblems ? :undecided: or have had a Knock sensor go bad ?
I did a search and didn't find anything
Help ? Any thoughts anybody ?

A knock sensor? You can unplug a knock sensor and keep driving unless it's knocking really bad. In that case the sensor is the least of your concerns. A knock sensor should have nothing to do with all the electrical problems you are having. I accidentally left one of my knock sensors unplugged one time. After driving it for four days (over 300 miles) it finally threw a code. I wouldn't have known otherwise because it showed absolutely no symptoms. Did they forget to plug it back in? There are two of them-one directly beneath the intake and one further back and lower on the block. I'll check my manual tonight about the electrical circuits.
 

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