[jaxx6911]

I apologize for the long post but I want to be thorough.

I bought a 2007 Colorado 2.9 WT from a dealership with around 70,000 miles on it, it had been a fleet vehicle. After a few days of owning it I realized the #3 position on the air didn't work, not a huge problem. I installed a tow hitch and trailer light connector(one recommended on a thread here, thank you very much for that) and installed them myself, other than that nothing has been done to the electrical system.

Here's where it gets weird.

I get out to my truck about two weeks ago and the battery is almost dead, truck barely started, no indication it had been slowing down at all. Bought a new battery and installed it.
Two days ago I replaced the plugs, boots, and springs. Yesterday I realize my A/C no longer works, and when I turn it on the electrical system is noticeably taxed. While I'm driving it the blinker sound randomly goes off(i.e. sounds without turning on blinkers) and when I do turn on my blinkers it is not in sync with the lights. Also, when I turn on my blinkers the lights in the cab dim every time the blinker lights(if the door is open). I tried leaving the battery unhooked for a while to drain the system in hopes that would do anything and all it did was reset the clock. A guy at the auto parts store said it sounded like a bad ground, I don't know how to check this or even if I can.

Should I take it to a dealer? It's not throwing codes or a check engine light. I'm really confused and any help would be great.

 

[colbyjohnson1994]

Dont take it to a dealer. There is an easy fix for all of this :th_woot:

Open your hood and find the two ground points located on the inner fender on both sides of the truck.

One is located behind your master cylinder/abs module. Take out the bolt to the ground pack. Sand the paint down and make sure the ground point is good and clean.

The other is located underneath the airbox (still attached to the fender). Do the same to that one.

To fix the fan, refer to this thread: http://www.355nation.net/forum/how-...fan-motor-resistor-connector-replacement.html

That thread also fixes the ground points.

:welcome2:

EDIT: I know this in the How To I linked you to, but here is how you fix the ground splices.

Ground Reconditioning & Repair

The Splice Pack (SP 106) and the Ground (G106) are suspected to be the primary cause for the resistor, connector, and harness overheating, arcing, and getting burned.

Method 1

Can be done without removing the air cleaner.
1. Remove the bolt holding the splice pack and ground from the inside of the fender. The bolt will stay with the strap.
2. Using sandpaper, or a flat file, or a dremel tool, remove the coating on both sides of the ground strap until you can see brass showing.
3. Remove the paint around the hole where the strap rests against the fender.
4. Place a 'star' washer on the bolt and slide it against the strap.
5. Reinstall the bolt, splice pack, and ground to the fender and tighten.
6. Apply several light coats of touch up paint or a bead of RTV to seal the connection.

Method 2
This is the method I used and requires removing the air cleaner.
1. Remove the bolt holding the splice pack and ground from the inside of the fender. The bolt will stay with the strap.
2. Work the bolt out of the strap; this requires a bit of patience, and discard the bolt.
3. Using sandpaper, or a flat file, or a dremel tool, remove the coating on both sides of the ground strap until you can see brass showing.
4. Remove the paint around the hole where the strap rests against the fender.
5. Run an M6 X 1.50 tap through the threads of the hole in the fender.
6. Place a star washer on a stainless steel M6 X 25mm bolt.
7. Put the bolt through the strap and place another star washer on the bolt.
8. Reinstall the bolt, splice pack, and ground to the fender and tighten.
9. Apply several light coats of touch up paint or a bead of RTV to seal the connection.

Method 3
1. Remove the bolt holding the splice pack and ground from the inside of the fender. The bolt will stay with the strap.
2. Work the bolt out of the strap; this requires a bit of patience, and save the bolt.
3. Using sandpaper, or a flat file, or a dremel tool, remove the coating on both sides of the ground strap until you can see brass showing.
4. Carefully break open the plastic box on the splice pack.
5. Cut off the wires where they connect inside and discard the plastic box and strap.
6. Strip off about 1/2"-3/4" of the insulation from each wire.
7. Divide the wires into two groups.
8. Place one group of wires into a ring terminal and crimp the terminal onto the wires.
9. Repeat Step 8 for the second group of wires.
10. Place a 'star' washer on the bolt and put it through the ring terminals.
11. Place another star washer on the bolt.
12. Install the bolt, washers, and terminals to the fender and tighten.
13. Apply several light coats of touch up paint or a bead of RTV to seal the connection.

 

[cart7881]

:welcome2:

Your problem with the battery draining is not related to the grounds. When an issue comes up, it is often due to a previous action. To troubleshoot, disconnect the wiring harness that you installed for the tow hitch and restore the OEM harness to the original configuration.

If your problem with the A/C started as a loss of fan speed 3, the first source to look at would be the resistor module. Most likely you will need a resistor module. Also check the resistor module wire connector for burned pins.

 

[rshadd]

When troubleshooting electrical issues, ask yourself "What's changed?" and take action to undo the recent change. Disconnect the towing harness that you recently installed and see if the issue goes away. If it does, you've found the source of your problem.

The A/C fan is a common issue on these vehicles. Follow the how-to and replace the resistor module.
http://www.355nation.net/forum/how-...fan-motor-resistor-connector-replacement.html

 

[colbyjohnson1994]

The ground straps can fix this problem => "While I'm driving it the blinker sound randomly goes off(i.e. sounds without turning on blinkers) and when I do turn on my blinkers it is not in sync with the lights. Also, when I turn on my blinkers the lights in the cab dim every time the blinker lights(if the door is open)"

 

[cart7881]

The ground straps can fix this problem => "While I'm driving it the blinker sound randomly goes off(i.e. sounds without turning on blinkers) and when I do turn on my blinkers it is not in sync with the lights. Also, when I turn on my blinkers the lights in the cab dim every time the blinker lights(if the door is open)"

That is a possibility. However, a bad ground is not going to drain the battery. The combination of unusual light issues, combined with a dead battery, points to other sources for the problem. The HVAC and the light issues are, of course, two separate problems.

 

[jaxx6911]

Thank you very much everyone for all the input. I will unhook my trailer lights AND do the ground strap fix and apparently the A/C resistors. If I think all the problems are fixed I can revisit the trailer lights when it is needed again.

I really appreciate the quick replies.

 

[cart7881]

How about let us know what happens when you disconnect the harness and replace the resistor module. Others in the future may have similar problems and come searching for help. Too many open ended Threads here.

 

[colbyjohnson1994]

Thank you very much everyone for all the input. I will unhook my trailer lights AND do the ground strap fix and apparently the A/C resistors. If I think all the problems are fixed I can revisit the trailer lights when it is needed again.

I really appreciate the quick replies.

No problem, keep us up to date :th_woot:

 

[Iceman62]

How about let us know what happens when you disconnect the harness and replace the resistor module. Others in the future may have similar problems and come searching for help. Too many open ended Threads here.

^^^Ditto^^^

Curious minds want to know if this is the major stem of your electrical woes.

 

[Rick_crew]

If you're competent to strip wires and properly attach a crimp-style ring-terminal, "Method 3" posted by colbyjohnson1994 is the best way to go..

Eliminate that silly "ground-pack" for good and never have to be concerned with it again.
Those things serve no purpose except to reduce assembly cost at the factory.
Spend the 2 hours or so to eliminate them and be a happier 355 owner.

 

[jaxx6911]

Ok, so I disconnected the fan plug under the glove box and it was about half melted. I'm buying the harness today and I will be fixing the grounding issue this weekend. I will fix the fan when the part arrives. I will keep everyone up to date and attempt to upload pictures. Thanks again.

 

[RidinBaseline]

I had some problems with my blinkers recently while pulling a trailer. Also recently had to change my alternator on an 05'. That might be something you want to look into. I was pulling a boat back to the house from the ramp when my radio flickered, then cutout, my dash lights went out, then my headlights went out. I drove around 8 miles with no lights. Luckily my friend was following me and kind of escorted me at one point. The truck was making some pretty wicked buzzing sounds at my cluster and the hazard lights were barely flashing. The truck would barely go about 20-25 mph. I thought I might have fried something by limping it home that way but I changed the alternator and so far so good.

 

[RidinBaseline]

Well I was wrong, turns out my alternator was still good. Might have just been the megafuse. Had to order a new one.

 

[RidinBaseline]

Well you can disregard my posts because it turns out that I had a bad battery. Didn't see it coming though since it was an 8 month old yellow top optima. Paid 4 dollars( the difference) to swap it out for a red top at autozone this afternoon.

 

[CUZICAN]

Optima's are junk!