light hook up issues

[Brocker]

Background: Everything on the car has been working fine. Engine runs well. All the button panel and dash working properly. The car is almost runnable except waiting for the tunnel cap and new shifter from DF. Had sent the fuse box to Lonnie a couple of weeks ago for a burned circuit board connection which prevented the fuel pump from functioning. He is amazing and wired the circuit board in the fuse box to correct the problem.

Problem: Hooked up the rear tail lights and side mirror turn signals yesterday according to what I found on the forum here and the engine began running rough - misfiring. The accelerator pedal would not function (ie. pushing the accelerator did nothing). Got a code (attached) which said: "P2138 $07E8 -- Throttle/Pedal Position Sensor/Switch D/E Voltage Correlation."

I unhooked all the light connections and restarted the engine. Ran fine. Deleted the above code. Ran another scan. No codes. I did order some resistors from Amazon (not delivered yet) just in case anyone advises me to place them somewhere. When it comes to electricity I just follow the directions - am clueless otherwise.

I'd like to get the car running so I can track it. Am willing to take it back to DF (10 hours away) to see if they can fix it. Can anyone help me to prevent that?

 

[Gtstorey]

About the only way this could happen would be a cross connected wire. Start by trying to tie it down to a particular light or pair of lights. If you are messing with any of the ground connection points when wiring in the lights check that also.

 

[Brocker]

I just checked all of the wires coming from the harness for lights for ground.
Turn stalks: both the orange and red wires on both sides are grounded
Headlights: both the black wire and one of the brown wires are grounded
Rear lights: both the black and brown wires are grounded.

Comments?

 

[Desert Sasqwatch]

How are you measuring these wires? Seems a little strange that all of them are 'grounded'.

 

[Brocker]

continuity tester to the grounds on the frame.

 

[Brocker]

The problem may be solved but I don’t know why. I unhooked the red wires that go to the side lights and everything started working. All the turn signals brake light headlights everything worked. No codes accelerator works. I guess hooking up those red wires was a no-no. Of course why are they there? Are those shorted to ground? Should I run new wires? Help please.

 

[Ross]

Brocker, what donor car do you have? Where does that red wire go? I don't have side lights on my car.

 

[Brocker]

2008 ss

 

[Gtstorey]

I have to admit I really don’t remember the colors for the lights, but I don’t remember any being red. You might want to rewatch the the wiring videos and see if you can track down where they come from.

 

[k.rollin]

I have to admit I really don’t remember the colors for the lights, but I don’t remember any being red. You might want to rewatch the the wiring videos and see if you can track down where they come from.

The Maxxima S/T/T lights used for the kit have red and white wires only. I don't remember any red wires for the tail lights on the donor side though.

 

[Joebob]

I remember the brown wires were the parking lights and should have +12v when the headlights are on. They should not be grounded if you are not using them.

 

[Gtstorey]

Did you unhook the lights while checking for ground? If not your "ground" signal was going to ground through the light.

 

[Chris_WNC]

The red extensions in the mirror turn signals come from a brown wire in the main harness. The orange extension wires in the mirror turn signal was tied to a ground lug.

CHRIS

 

[Brocker]

After months of going through the engine and main harness wire by wire I believe we found the source of the problem with my Goblin (Gobalt).
It was the ground! The ground wire from the battery to the frame had 8 ohms of resistance. The ground cable from the engine to the frame had 5 ohms of resistance. According to the GM tech working with me (as a friend), the total ideal ground from battery to the engine should be around 0.3-0.4 ohms. He hypothesized that my hooking up the turn signal light put too much of a load on the system (straw that broke the camel's back) which caused the harness to ground through the ECM. We had to replace both the ECM and the high speed fuel harness. My wiring harness had NO shorts anywhere. Hard lesson to learn. While I bought the donor car in Georgia, the car spent most of it's life in Illinois. While the ground cables all looked fine they were not. Check your ground cables if you have a northern donor!
After replacing the grounds and the ECM it all starting working fine. Hope to hit the road soon!!

 

[Sluggonaut]

I've read about others with ground wires that looked fine but then failed.

For those of us in the rust belt, what can we do to check the quality of our grounds prior to testing them under load? Just check resistance as you described?

 

[r3drckt]

Once you have things grounded, you can use a volt meter and test the copper lug on one probe with the negative battery post on the other probe, like how DF tests the lugs in the video basically.

 

[Brocker]

I just replaced all the ground strap cables with new and very carefully wirebrushed all the connections to the frame ground lugs, washers, and nuts -- removing any paint, rust, corrosion etc. Once that was done I ran my fluke meter from the battery to the engine area ground lug. My overall resistance measures between 0.3 and 0.4 Ohms. Before it measured 17 Ohms.
One of the funny things that also happened, besides the engine running well, was that the flashers started working and the headlights also worked properly. Before I cleaned up all the grounds, the headlights functioned in reverse on the stalk. The high beams were in the low position and the lows in the high. The flashers would not work at all. Once the grounds were fixed everything worked properly!!! Wow.
I don't really understand these electrical systems with their 5 volt references etc. but the electrical engineers at GM do. The whole system appears to be quite fussy!