V1 Carl's Track Goblin - 05 SS SC donor, Chassis # 39

[Briann1177]

It looks like the "Class 2 Serial Data" is a dedicated diagnostic line. I wonder if you have those two green wires connected together somewhere? I don't think you should have continuity between pin 1 and pin 2 of your OBD2 port since they're completely different circuits.

Just a quick thought to check.

 

[Waterdriver]

I pulled up the OBD2 port connector for an '05, and it looks like there is only one positive wire. There are two grounds however.

It also looks like the LSJs have two dark green wires right next to each other in the OBD2 connector. One is for low speed GMLAN and the other is "PCM Class 2 Serial Data (LSJ)". Not sure what the latter is. I wonder if something got mixed up when you removed the splice pack?

I believe the only thing in common between your OBD2 port and the gauge cluster is that green wire on pin 1.

I can't explain why your gauges work when you have your scan tool plugged in. That's very odd.

I'm thinking that when I plug that Bluetooth adapter in, its connecting some of those OBD2 connections together.

I'll check both those grounds you mentioned for continuity first to see if that might be the issue. Seems like a lot of issues people come across are related to grounding or lack thereof.
I would think that if it was GMLAN or other communication wiring issue, the gauges wouldn't work with or without the Bluetooth adapter. I think that adapter might be providing/jumping the ground the gauges need to work.
Thanks for looking into it and the recommendation. I'll post what I find out.

 

[Waterdriver]

On another note, I finally parted ways with the donor.

Got a whopping $56 for it. It sure made my wife happy to see it go.

 

[BaltimoreHokie]

I gave mine away but had them pick it up from my house. I was just glad it was gone honestly. I am sure you are too.

 

[Waterdriver]

First start video.

Issue was the MAF was backwards to airflow. Flipped MAF tube around it idles like it should now.

 

[Briann1177]

You could have sold the doors and probably at least doubled your profits.

 

[Waterdriver]

I gave mine away but had them pick it up from my house. I was just glad it was gone honestly. I am sure you are too.

Yeah, it's nice to have my trailer back so I can use it for other things.

 

[Waterdriver]

You could have sold the doors and probably at least doubled your profits.

I had them posted on craigslist a couple of different times but didn't get any bites. Front fenders were still good too. Oh well it's someone pick n pulls now.

 

[KJP]

You could have sold the doors and probably at least doubled your profits.

I have two mint black doors and I cannot get rid of them!

 

[TheNuker]

Dang, I sold both of my black SS doors for 100$ each!

Nuker-

 

[Ben Eldridge-Peter]

Im having trouble parting out anything.

 

[ctuinstra]

Im having trouble parting out anything.

Don't feel bad. I answered a lot of requests and priced many items only to not sell a dang thing! I got tired of all of the idiots just kicking tires and wasting time. I did sell the wheels and tires just recently, I kept them thinking I was going to use them on the car but didn't.

 

[BaltimoreHokie]

Don't feel bad. I answered a lot of requests and priced many items only to not sell a dang thing! I got tired of all of the idiots just kicking tires and wasting time. I did sell the wheels and tires just recently, I kept them thinking I was going to use them on the car but didn't.

I sold about 1k with of stuff. Almost my donor cost. I still have a decent amount but no interest. Takes up space and aggravates me when people request info that's already in the listing them never respond.

 

[KJP]

I sold about 1k with of stuff. Almost my donor cost. I still have a decent amount but no interest. Takes up space and aggravates me when people request info that's already in the listing them never respond.

This was my general experience. I think it has to do with most of these being owned by high school kids. I have however sold enough to cover all but 450 of my donor including the cost of picking it up and registering it. I still have some parts eating up space. I will give it a bit longer before I just throw away or scrap them.

 

[Waterdriver]

It looks like the "Class 2 Serial Data" is a dedicated diagnostic line. I wonder if you have those two green wires connected together somewhere? I don't think you should have continuity between pin 1 and pin 2 of your OBD2 port since they're completely different circuits.

Just a quick thought to check.

Last night I was doing a little wiring diagnostics starting at the OBD2 port. Ground wire has a good ground.
Green wires, no continuity between them.
Started checking ground wire to chassis points back to the negative battery cable. Found that the ground cable I have attached to the pedal box was showing a low value of resistance.
Removed that cable, cleaned paint and primer off the mounting point and reattached.
The tachometer is now working but the speedo is showing a value as well. Could be the trans is freewheeling at idle since the axles aren't in at the moment.

 

[Briann1177]

You want a low value resistance when it comes to ground wires. The lower the better. I don't think the build videos mention this, but yeah, you definitely need to clean paint or powder coat on the area where the pedal box mounts to the frame. Just cleaning where the grounds attach to won't be good enough.

 

[Briann1177]

I'm also glad you figured it out. Ground issues are a ***** to troubleshoot, but fortunately they're easy to fix. Good to know you didn't have something cross wired like I was thinking.

 

[Waterdriver]

You want a low value resistance when it comes to ground wires. The lower the better. I don't think the build videos mention this, but yeah, you definitely need to clean paint or powder coat on the area where the pedal box mounts to the frame. Just cleaning where the grounds attach to won't be good enough.

I had checked that ground before when bolting that ground lug and it read zero resistance.
A low reading of resistance is resistance to a good or complete ground for a ground wire. A zero resistance ground reading on the multimeter is a good ground. Unless of course your measuring a ground through a resistor.

 

[Karter2026]

That is part of the reason that I linked all of my grounds together. An extra 10 feet of wire is cheap insurance

 

[Briann1177]

Don't let a zero resistance fool you. It could have been making contact through a tiny chip in the paint or whatever causing it to just be flaky enough to make you think it's good but still cause a problem.