# Problem with my truck electrical



## Calidecks (Nov 19, 2011)

m1911 said:


> yup, intermittent problems are definitely a pita.
> 
> rent the same truck for a day, and swap the BCM to test it... LOL


Where's the BCM and what does it look like


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## m1911 (Feb 24, 2009)

Californiadecks said:


> Where's the BCM and what does it look like


rectangular box under dash, steering side. if you replace it, it has to be reprogrammed to your truck.


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## m1911 (Feb 24, 2009)

do a good wiggle test and check all the connections real good, before condemning any parts...


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## Frank Castle (Dec 27, 2011)

Unplug the BCM and plug it back in. Might be a bad connection that the unplug/plug fixes.

I had problems with BCM on my dodge, my guy unplugged, tested, test said no problem. Re-plugged, things have worked fine since.

I keep waiting for another problem.


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## Calidecks (Nov 19, 2011)

This?


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## Calidecks (Nov 19, 2011)

m1911 said:


> rectangular box under dash, steering side. if you replace it, it has to be reprogrammed to your truck.


Can any electrical tech do the reprogramming or will they have to send it to the dealer? Thanks. And if I replace the BCM will it be drivable enough to get it to a place for reprogramming?


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## Leo G (May 12, 2005)

Californiadecks said:


> I looked, but probably in the wrong place. Hell I've been looking on the Internet for hours. I'd be willing to give a 1000 bucks or even more, for a proper diagnosis.
> 
> The issue is, what do you put in the search engine to lead to the right place?


Disconnect the battery, the problem will go away.

I'll PM you my address for the check :laughing:


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## Peter_C (Nov 26, 2014)

Californiadecks said:


> Can any electrical tech do the reprogramming or will they have to send it to the dealer? Thanks. And if I replace the BCM will it be drivable enough to get it to a place for reprogramming?


It depends if the shop is well equipped, and has a J2534 programmer. Today you almost need to be able to code just to replace parts on a vehicle. The BCM has to be programmed for sure and I wouldn't even turn the key on with a new BCM installed without a scanner plugged in ready to program. Any shop that is heavy into diagnostics will be able to do it. 

You can not just swap computer parts from one vehicle to another anymore. It can wreak havoc on the PCM. 

Still you need to ground the correct wire for the door pin switch coming into the BCM to see if it fixes it. Make a semi permanent ground and drive it for a week. You should be able to find the BCM wiring diagram on google images. The one you posted is a partial of what you need. Could easily save paying someone hundreds of dollars and losing your truck for days. 
https://www.google.com/search?biw=1...9.9.9.0....0...1c.1.64.img..0.0.0.pqvq5mbH8hw

Different year but it could be the same. A5 on connecter, black/white wire at BCM. Last diagram in this post, on the right side. "Right Front Door Ajar SW" Pining into with a DVOM grounded on one side and set to ohms or voltage, then opening and closing the door will answer any questions. Don't just ground it until confirming it is the door switch. 
http://www.justanswer.com/chevy/3hcsz-need-bcm-pinout-2007-silverado-duramax-6l-truck.html

It is hard to be 100% certain without the actual wiring diagram. Snap-on's wiring diagrams are the best though!

A paper clip slid in next to the wire, then lightly taped to hold it in place should do the trick. Wrap some copper wire around it and bend the paper clip around the wire using pliers for a solid connection. Find a good place to ground the wire that isn't covered in paint. Under a bolt or screw should work.


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## Peter_C (Nov 26, 2014)

Here are some of the best auto shops around. Not the only ones, just member of IATN which means they are striving for success.
https://iatn.net/repair/?action=sea..._lat=33.8508021&gc_lng=-117.7490656&show_all=

I would swear Dean Parsons shop was somewhere in the LA area. He is one of my favorite instructors. They fix the vehicles the dealers can't. You could contact ATG and maybe get his email or shop name and location?
ATG
 – Automotive Training Group 
www.atgtraining.com
 – Advanced training various topics. 800-233-3182, 
Advanced Circuit Diagnosis class available on March 2, 3 2016, instructor Dean Parsons @ Tec-Help Training Center 


These guys at Tec-help definitely know Dean Parsons really well. He teaches classes out of their shop. They will know Dean's shop name and address. Send them an email asking for his shop name/address and maybe email if the shop isn't in your area, he could recommend a good local shop. 
http://tec-help.com/contact/


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## rescraft (Nov 28, 2007)

Mike, you make so much money; just buy a new one!


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## m1911 (Feb 24, 2009)

rescraft said:


> Mike, you make so much money; just buy a new one!


But the challenge of fixing it yourself keeps your mind sharp...


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## Leo G (May 12, 2005)

m1911 said:


> But the challenge of fixing it yourself keeps your mind sharp...


Or just pisses you off more and more.


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## Calidecks (Nov 19, 2011)

I'm seriously contemplated buying a new truck.

I have a moral question. Do I tell Carmax?


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## griz (Nov 26, 2009)

Californiadecks said:


> I'm seriously contemplated buying a new truck.
> 
> I have a moral question. Do I tell Carmax?


its a dam electrical problem on a vehicle.

you are doing well, dont let karma for a few bucks return and bite your ass.

tell the dealer or carmax or who ever about the issue.

sleep well.....


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## 91782 (Sep 6, 2012)

griz said:


> its a dam electrical problem on a vehicle.
> 
> you are doing well, dont let karma for a few bucks return and bite your ass.
> 
> ...


Or pay the dealer to fix the damned thing AND trade it in.


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## Inner10 (Mar 12, 2009)

Californiadecks said:


> I'm seriously contemplated buying a new truck.
> 
> I have a moral question. Do I tell Carmax?


The headlight stopped working in my almost 4 year old truck so I bought a new one. I ain't got time for that ****.


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## Inner10 (Mar 12, 2009)

Or sell that turkey to Bam!


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## Calidecks (Nov 19, 2011)

griz said:


> its a dam electrical problem on a vehicle.
> 
> you are doing well, dont let karma for a few bucks return and bite your ass.
> 
> ...


Yeah I don't need to steal anything from anybody. Because that's exactly what that would be doing. However, I don't have to tell them how much it's messing with me and that is the reason I'm selling it. Or do I? I just tell them the door chime keeps coming on maybe one of your mechanics can fix it. That's it.


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## TimNJ (Sep 7, 2005)

griz said:


> its a dam electrical problem on a vehicle.
> 
> you are doing well, dont let karma for a few bucks return and bite your ass.
> 
> ...


If he trades it in you can bet they will hook it up to see what kind of codes are thrown.
For service, they "can't find anything wrong".

For trade in, they will find everything down to a paint chip in the frame in order to drive the value down.


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## Calidecks (Nov 19, 2011)

TimNJ said:


> If he trades it in you can bet they will hook it up to see what kind of codes are thrown.
> For service, they "can't find anything wrong".
> 
> For trade in, they will find everything down to a paint chip in the frame in order to drive the value down.


I never trade vehicles in. Also there's no service code for the "passenger door open" prompt. Especially when the problems intermittent. I'm going on two days now without it chiming. I did an extensive wiggle test under the dash at the BCM and it went away. I'm not expecting it to last though.


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## m1911 (Feb 24, 2009)

Peter_C said:


> Dome light turned on or off has nothing to do with the door chime, and door ajar light.


Unless it has a bad ground at the dome light, and it's back feeding. Perhaps?


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## Peter_C (Nov 26, 2014)

m1911 said:


> Unless it has a bad ground at the dome light, and it's back feeding. Perhaps?


Bad ground wouldn't cause a problem, except the light wouldn't come on. 

It does beg the question though, is it controlled on the ground side?? Still doubtful, although they are both controlled by the BCM, and use the same switch, the outputs are different circuits. Dome is fed over to the dimmer area switch for bypass.


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## m1911 (Feb 24, 2009)

Peter_C said:


> Bad ground wouldn't cause a problem, except the light wouldn't come on.
> 
> It does beg the question though, is it controlled on the ground side?? Still doubtful, although they are both controlled by the BCM, and use the same switch, the outputs are different circuits. Dome is fed over to the dimmer area switch for bypass.


Not sure. I was a VW audi tech, so I have experience with German cars and the wiring color codes are more consistent and logical.

I think Fords have positive ground on the door light?


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## Calidecks (Nov 19, 2011)

So far so good no issue today either. If I get through tomorrow it will have gone the longest yet without issue.


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## Peter_C (Nov 26, 2014)

m1911 said:


> Not sure. I was a VW audi tech, so I have experience with German cars and the wiring color codes are more consistent and logical.
> 
> I think Fords have positive ground on the door light?


Ha! My last job actually repairing vehicles I specialized in Porsche's and I got bored, so I convinced the boss that since pretty much every customer had an Audi we should start taking care of them too. I love German cars, and have owned numerous Audi's myself. Today they are becoming more similar than different. 

Kinda hard to have a positive ground in a standard vehicle electrical system  Old skool cars were positive ground though. It is very common to control the ground side of a circuit though.


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## Artworks (Dec 5, 2009)

You may have a back feed from another source. I know older chev's would light up the dome light if another fuse was blown. And , in my experience with auto electrical, first thing is "GO TO THE GROUND" any and all grounds can be a problem. ( a bad ground made my airbag light come on and stall out once in awhile. Pull the ECM fuse for couple seconds, truck would run ok for couple days. Took a bit of looking before I found it. ) A lot of auto tech's now don't know how to troubleshoot problems if it doesn't show on the scanner ! Multi meter is your friend. Good Luck.


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## Calidecks (Nov 19, 2011)

Well damn, this is day eight and no issues!


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## m1911 (Feb 24, 2009)

Californiadecks said:


> Well damn, this is day eight and no issues!


Knock on wood (does composite work?)... :laughing:


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## Calidecks (Nov 19, 2011)

m1911 said:


> Knock on wood (does composite work?)... :laughing:


It's a high performance wood alternative. That's the story I tell anyway. :laughing:


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## Calidecks (Nov 19, 2011)

You guys may have saved me 15 or 20k.


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## m1911 (Feb 24, 2009)

Lol


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## Leo G (May 12, 2005)

Californiadecks said:


> You guys may have saved me 15 or 20k.


Where's our check then? :whistling


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## Calidecks (Nov 19, 2011)

Leo G said:


> Where's our check then? :whistling


It's in the mail of course


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## Leo G (May 12, 2005)

I'll be waiting anxiously. :laughing:


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## Calidecks (Nov 19, 2011)

Id just wait by the mailbox if I was you.


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## Leo G (May 12, 2005)

I sitting there right now. 3 days from CA to CT. I can't wait.


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## 91782 (Sep 6, 2012)

I sense a class-action lien about to happen.


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## Calidecks (Nov 19, 2011)

Californiadecks said:


> I looked, but probably in the wrong place. Hell I've been looking on the Internet for hours. I'd be willing to give a 1000 bucks or even more, for a proper diagnosis.
> 
> The issue is, what do you put in the search engine to lead to the right place?


Well ya all know I meant I'd pay a shop 1000 bucks. However I still don't technically have a diagnosis. :whistling


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## 91782 (Sep 6, 2012)

Just like a typical homeowner - won't ask one question while the work is going on, but once it's time to pay they get all Bill Nye Science Guy with the questions.


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## Peter_C (Nov 26, 2014)

Californiadecks said:


> Well ya all know I meant I'd pay a shop 1000 bucks. However I still don't technically have a diagnosis. :whistling


Well I have an auto shop at my house 

Sure you have a diagnosis, the problem is a poor connection in the electrical system. Where it is/was, is still unknown. 

I got a lawyer on retention for that class action suit :jester:


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