Fun Electrical Issues... Grounding Areas to Check?

[XBrav]

Hey all,

I've been having a lot of "fun" with my '09 1500 5.7. I figured I'd toss a line out and see if anybody had any recommendations of what to look at first before I start probing all my wires.

Ever since I got my Ram last year (Body bought at auction due to a blown engine (~259,000 km). Swapped with a 2010 5.7 with around 200,000 km on it), I've had some odd issues that's leading me to an overall electrical issue due to how sporatic and spread out it is.

We used a HP Tuner to delete the MDS originally after seeing some of the MDS solenoids occasionally not actuating as expected. With a scanner, the solenoids all stroked as expected, but occasionally one wouldn't, causing the engine to shake like hell. A quick pull off the road and restart, and all would be well. We pulled and swapped the solenoids, rotated them, etc. There was no repeatable pattern we could see. Disabling it outright prevented the issue, so we decided to leave without the system engaged.

We also noticed the occasional code regarding the rear left speed sensor having issues. Through a combination of playing with it, the error seemingly went away since.

After installing an aftermarket remote start, there were times where the module wouldn't lock / unlock / start successfully. Many times, simply getting into the cab and turning to MAR / ON. The vehicle would immediately auto-crank if it was previously requested. I noticed on the scans that there was sometimes a B3004, and this would line up with a door sensor fault causing the auto-start and lock / unlock to act up.

I've recently been seeing a C1036 and C1436 occasionally pop up, but it never seemed to activate the CELs or jingle when rolling. Yesterday, while driving on the highway, I hit a pothole (just enough to cause a shake luckily) and my dash lit up like a tree. From what I recall, I had ABS, Stability Control and SERV 4WD active. Pulled off the highway and scanned with AlfaOBD. The ABS seemed to be the driver reporting an invalid wheel speed on my rear right wheel. I checked the remaining systems, and inspected the wiring harness and connector to the rear sensor. After inspecting, I got back on the road and the lights all cleared within 1km (I wasn't even back on the highway yet).

For the remainder of the drive, there was no major issues. It seemed whenever I hit a rough patch of road, the rear right signal was interrupted briefly, causing my cruise control to deactivate. There were no jingles, but I recall seeing the ABS light flicker once or twice when this happened.

I'm likely going to replace the speed sensors for good measure. Seeing the above issues, does it sound like a power issue? Are there any particular grounds that commonly fail? I'm hoping it's not the TIPM, but I know they tend to have issues.

 

[Oliver Closehauf]

Isn't there a connector between the cab section and bed section of the wiring harness somewhere? I thought I read a post about someone cutting the harness only to find a connector.

In another car I've had the wheel sensor wire which looks like thin cable TV cable, break the copper core without showing on the outside. The constant up down of the suspension caused it to bend back and forth and break, but the shielded ground outer section was fine. It was intermittent but when it couldn't get a read, the body control computer told the ECU to put the engine in limp home mode. So you might be onto it with the idea to change them out.

 

[XBrav]

Isn't there a connector between the cab section and bed section of the wiring harness somewhere? I thought I read a post about someone cutting the harness only to find a connector.

In another car I've had the wheel sensor wire which looks like thin cable TV cable, break the copper core without showing on the outside. The constant up down of the suspension caused it to bend back and forth and break, but the shielded ground outer section was fine. It was intermittent but when it couldn't get a read, the body control computer told the ECU to put the engine in limp home mode. So you might be onto it with the idea to change them out.

According to the drawings, there's no breaks between the 46 way connector and the end device connectors.

I did notice the cable wasn't fixed to the frame at the back, so the miles may have caught up with the strands. I'll definitely be checking the wire resistance if it continues to act up.

I took the opportunity to inspect the TIPM connections today. They all look great, but I did notice a rat's nest underneath it. Luckily, the wires didn't look like they had any damage to the shielding. There was a single crimp I'll need to check out, but I've reseated the whole assembly just to be sure it wasn't a corroded contact. I didn't see a need to spray all the connectors with Deoxit, but at least it's all accessible. The TIPM isn't exactly secured well in this one...

 

[XBrav]

Today's update:
I reviewed the wiring around the rear speed sensor. I wasn't able to remove the connector at the time, so I reviewed the wiring. It looks like someone replaced it at some point, so I'll definitely consider replacing the wire up to a higher splice point.

I am unsure at this stage if the sensor itself is intermittent. My knowledge of these sensors is based on my industrial controls experience. The loop looks to be open, as the failure is registering a speed of 655.35km/h from the ABS module. Until the failure, the sensor appears to be responding with a healthy pulse as the ABS module is calculating a matching speed with the other 3 wheels.

On a positive note, no new electrical issues have arisen since fiddling with the connectors and reseating the TIPM. I bought and installed a battery anchor and replaced the battery terminal connectors for good measure (they were in pretty horrible shape from people mangling them previously).

Hopefully I'm on the road to success here... Thank god for AlfaOBD.