[sjmiii]

I'm sure this problem has never come up, but I am the king of weird electrical problems that no one has ever had. So with that said, let's get to the issues and what's been done.
I bought this truck brand new in 2012 and other than the exhaust, it is bone stock. I have had relay issues with this thing since it was almost new. I have personally had to replace every relay in the under hood relay center at least once. Problems from lights not working to wipers quitting and so on. It has always been a faulty relay.
Recently my issues are as follows....Most of the time I can get in the truck and start it and drive a normal day. Last week I was driving home from work while raining. I thought I felt the truck lose power suddenly and then pick up again. I chalked it up to traction control and forgot about it. As I was coming to a stop at the end of the ramp the truck just dies. I put it in park and restart it. Put it in drive and it stalls again. Whenever the truck stalls the wipers come on at about the third of the speed as they normally would be on. I finally get the truck started and put in gear and the passlock light was on. I drive the truck home, about 5 more miles and the light is still on. I pull in the drive and shut the truck off for a few minutes and turn back on and light is off. Several times after this the truck has shut down on me while driving but the passlock light has not come on but the wipers will come on whenever this happens. Sometimes the abs light and stability lights will come on when this happens too.
Seeing all the problems I have had with relays, I put a new under hood fuse box in the truck that has all new relays and fuses. While the box was out I tightened all the pins on the plugs to the fuse box. I started the truck several times but later when I went to leave the truck would start and as soon as I put it in gear it would die. It did this 3 times and hasn't done it since. I pulled the kick panel and worked the plugs on the bcm and looked at wiring. When I plug into the truck with the tech2 I have no codes.
I have added extra grounds to the splice pack grounds on the front left fender and have cleaned the right side a while back due to the notorious blower motor problem. All of my issues I have had to fix myself with this truck since the day I picked it up because when I would take it to the dealer when it was under warranty they would just drive it all day until it was almost out of gas and tell me they couldnt duplicate the problem. Sorry for the long post but wanted to give as much history as possible. Any help would be appreciated. I'm now thinking BCM after the fuse box did nothing.

 

[hammer mechanic]

OH yuck intermittent electrical what a nightmare for you to have. Sorry. My first thoughts go to water getting to the PCM, you mentioned rain. Mouse wiring damage. You replaced the fuse box was it NEW or used? I and others here have had corroded ( fretting ) in the fuse blocks and there is a how to here to clean them up. And with you having your used fuse block you could clean that one. I had the PCM fail and it stalled on braking and did not want to restart BUT it gave me the code for it. There is also a BCM ground under the passengers seat you may want to look at. Check and clean the engine block ground.
Hope I gave you so other ideas.
LUCK

 

[sjmiii]

I will look for that ground under the seat. The wiring looks to have no issues at all. The truck has like 75000 miles and has had one issue after the other (always electrical) I removed the pcm connectors Saturday and inspected and worked the plugs. Only reason I was thinking bcm was because of the passlock, abs and wiper issues when it happens. The fuse block i put in was new from a dealer in Pa.

 

[raterr]

I'm sure this problem has never come up, but I am the king of weird electrical problems that no one has ever had. So with that said, let's get to the issues and what's been done.
I bought this truck brand new in 2012 and other than the exhaust, it is bone stock. I have had relay issues with this thing since it was almost new. I have personally had to replace every relay in the under hood relay center at least once. Problems from lights not working to wipers quitting and so on. It has always been a faulty relay.
Recently my issues are as follows....Most of the time I can get in the truck and start it and drive a normal day. Last week I was driving home from work while raining. I thought I felt the truck lose power suddenly and then pick up again. I chalked it up to traction control and forgot about it. As I was coming to a stop at the end of the ramp the truck just dies. I put it in park and restart it. Put it in drive and it stalls again. Whenever the truck stalls the wipers come on at about the third of the speed as they normally would be on. I finally get the truck started and put in gear and the passlock light was on. I drive the truck home, about 5 more miles and the light is still on. I pull in the drive and shut the truck off for a few minutes and turn back on and light is off. Several times after this the truck has shut down on me while driving but the passlock light has not come on but the wipers will come on whenever this happens. Sometimes the abs light and stability lights will come on when this happens too.
Seeing all the problems I have had with relays, I put a new under hood fuse box in the truck that has all new relays and fuses. While the box was out I tightened all the pins on the plugs to the fuse box. I started the truck several times but later when I went to leave the truck would start and as soon as I put it in gear it would die. It did this 3 times and hasn't done it since. I pulled the kick panel and worked the plugs on the bcm and looked at wiring. When I plug into the truck with the tech2 I have no codes.
I have added extra grounds to the splice pack grounds on the front left fender and have cleaned the right side a while back due to the notorious blower motor problem. All of my issues I have had to fix myself with this truck since the day I picked it up because when I would take it to the dealer when it was under warranty they would just drive it all day until it was almost out of gas and tell me they couldnt duplicate the problem. Sorry for the long post but wanted to give as much history as possible. Any help would be appreciated. I'm now thinking BCM after the fuse box did nothing.

You mentioned the blower motor; did you replace it? All my electrical issues went away after I changed the blower motor on my 2010 Colorado V8. Unbelievable! No more Passlock problems and No more HVAC problems.

 

[OldGuy]

I've had 2 vehicles that have had "haunted" wiper motors. Strange experience! When you turn your wipers off, the motor gets to the down position and contact is made that makes the wipers stop working. When those contacts get worn out, and don't make good contact, the wipers don't know they are in the correct "down" position anymore, so they start working again. On the first vehicle with the problem (Dodge Caravan) I just threw the motor away and got a new one. On my Colorado, I fiddled around with it a little bit and found that it was a ground problem. Our truck are riddled with electrical issues because all of the wiring seems to be a much smaller gauge that what I'm used to on other vehicles. The wiring for the tail lights is absurd! If your experiencing most of these problems at night, or when it's raining an the headlights come on, you may have a problem with the tail light wiring. After constantly having electrical problems including tail lights that don't work, but the bulbs are still good, I replaced the tail light sockets. The parts store didn't have to parts for a Colorado, but recommended Silverado bulb sockets. I had to fiddle around a little to get the wires attached correctly, but that actually took care of all of my electrical issues. Our center tail light has 5 wires!