Posessed 2007 Chevy Express G2500

[DavidDeBord]

Greetings!

 

I'm rebuilding a 2007 Chevy Express G2500, that had been wrecked in the front end. We've straightened the frame, replaced grill, bumper,& hood.  Prior to this work, the Dash Cluster operated properly, but,... After getting the above work done, the Dash Cluster Gauges would come on, & then the Voltage, Oil, Temperature gauges would rise & fall, & the "Security" & "Check Engine"& "Battery"  indicators would come on & then off. Putting a load on the Van, by turning on headlights, Flashers, & radio, has no effect, BUT,.... When the Gauges fall down,... The Radio quit working.  I stumbled in to learning that when the brake pedal was "Tapped", that everything would return to normal, but within 3 to 5 seconds, the "Possession of the Van" would start all over again. 

 

I then found that by putting slight pressure &/or pressing the brake pedal, that this issue disappears.

 

No Fuses have blown, & so far, I have not found any wire,directly making contact with the brake pedal assembly, neither under the dash, nor at the firewall near the Brake booster/reservoir assembly.

 

Do You have any ideas, any data, or any sources that you could direct me, so as to solve this problem? 

 

I am familiar with a Service Bulletin that had been issued via GM, that was addressing an issue similar to this, with part of the problem being in the wiring harness close to the "Brake Switch", but, have a problem in locating that Bulletin in the many files/Downloads/Videos that I have saved for my van. 

 

Regards,

David

[DavidDeBord]

Greetings Ya'll! 

 

This is my first post & more than likely there will be many more, as I rebuild my van

 

I bought a wrecked in the front end 2007 Chevy EXpress G2500, & after having straightened the frame, replaced the bumper & grill, lights, & hood, the Dash Cluster Gauges, & Indicator lights which had no problem before, then began to operate in an insane manner! The Temp., Oil, & Battery Gauges would rise & fall, & the "Security", "Check Engine", would go on & off.  I put a "load" on the system by tuning on the headlights, heater, & radio, but they had No Effect on what was happening, BUT,...... when the Gauges fell to 0, the radio also quit working every time, but the Heater Blower, Hazard lights, & Headlights continued to operate with no problems. 

 

I found by accident that by pressing on the brake pedal, & releasing it that everything would return to normal, including the radio for about 3-5 seconds, but then the "Van Possession" would then return. Again, nothing happens to the Hazards, Blower motor, nor Headlights.

 

Now here's Th' Kicker,... When I depress the Brake Pedal, the Dash Cluster works perfectly. When I release the brake pedal, then within 3-5 seconds the Dash Cluster & Radio then start the whole insane process over again.

 

Has anybody experienced this, & if so, how did you fix this nightmare? Is there a ground that may have become disconnected during Our Repairs, that is specific for the Dash & Radio?

 

And, can anyone tell me where to get the Dash wring diagram? 

 

 

[Jsdirt]

Sounds to me like there's a ground with either a bad connection, or is not connected at all. With lack of ground, power will find other ways to get back to the battery, causing all kinds of strange issues. The good part is, you can concentrate on the front half of the vehicle to find it.

[C/K Man]

My first thought would be to check all the grounds in the dash and front end.  Also, if you replaced the cluster, did you have it programmed to the truck?  Best place to find a wiring diagram is in the factory shop manual, you might be able to find one reasonable on Ebay.

[DavidDeBord]

Greetings C/K,

 

Do you know of any GM Document, on Th' Net, that gives the location of the Frame, Body, Dash, & Motor Grounds? 

 

And, I've not replaced the Dash Cluster yet, and I'm thinking that it has more to do with a Ground,due to the Radio operating erratically, & that it everything goes back to normal when the brake pedal is depressed.

 

And, I'm going to hunt down that Factory Shop Manual that You mentioned.

 

[C/K Man]

The manual is best because it also has a component locater section which will show you exactly where the grounds (and other connectors and components) are located.  You might get lucky on the web but I don't know of any specific sites.

[diyer2]

Try this

https://www.factoryrepairmanuals.com/2007-chevy-express-gmc-savana-van-factory-service-manual-shop-repair-set/

$395

Or

https://www.onlymanuals.com/chevrolet/express

Or

https://www.motorera.com/auto-service-repair-manual/Chevrolet/Express

 

 

Edited March 29, 2022 by diyer2

[DavidDeBord]

Thank You C/KMan & diyer2!

 

I'll look in to the Manuals for sure.

 

What's been baffling me is how the radio quits working while all of this is ongoing, .... Other than possibly a Common Ground, do Ya'll know if whether the Dash Cluster also controls the radio?

 

And again Thank You!

[DavidDeBord]

Greetings Jsdirt,

 

I have to apologize, I just saw your reply, & I never got a notification about any reply.

 

With My & My Son's work,& many other issues, we've made very little progress on working on my van.

 

Today, I learned about a ground location, via  a video from "Etrailer" about how to install a "trailer brake controller", as well as the ground wire & hot wire color that feeds the brake switch, & I'm hoping to get back over to work on the Van, & ck out these grounds & wires, work permitting, early next week.

 

And I appreciate your help Js!

[Jsdirt]

No problem. 

 

There's usually a couple critical grounding points up front, such as one at the left body mount by the driver's door, and another on the back of one of the cylinder heads - I forget which one, but it's there. Also don't forget the basics like the battery connections and cables - check BOTH ends of the cables for a good connection.