After 18 years of interesting CTD enthusiasts and transmission specialty outlets all contributing their method, or fix, to the well known TC lock unlock syndrome, I can no longer remain silent.

 

Extensive review of many posts regarding TC lock unlock, the rerouting methodes, the add on filters for APPS and last, but not least,...the "tin-foil hat" brigade. I do realize that each individual or company that contributed to the vast amount of information on the web had good intentions and I must acknowledge that some of the procedures caused me to closely examine what these people were trying to do. I believe it is well known that even a blind mouse occasionally finds a morsel of cheese.

 

Again, as it is well known @Mopar1973Man  was the only entity who positively identified the instigating source of this key issue. My entry today is not about alternators...it is about what Daimler/Chrysler did in regard to production of these Cummins powered platforms and the complete disregard of common sense Electronic Engineering.  Please note, this applies to automatic and manual transmissions as each platform is plagued in the same manor with different quirks. 

 

This Blk/Tan #8 gage wire is quite critical in the scheme of things. It is contained within a 1" plastic conduit passing along the front of the engine. It contains water temp sensor leads, air conditioning leads, alternator/PCM leads and the #6 gage alternator charge line to the PDC. This #8 gage Blk/Tan passes over the top/backend of the alternator and is "eventually" connected to the Auxiliary Battery (passenger side) negative terminal.

  

This snapshot of the Factory Service manual documents "four critical ground leads" that are "spliced" in an unconventional method.

 

This photo depicts the three #18 gage wires and the single #14 gage wire entering the shrink-tubing where the "crush-splice" occurs. This bundle exits the large plastic conduit below the VP44

 

This again is a most disturbing depiction of the Daimler/Chrysler method of splicing critical ground leads and then routing this across the top of the alternator and "eventually" bringing this to ground reference. 

 

This photo depicts where this #8 gage Blk/Tan first connects on the way to "eventual" ground...yes this is the Auxiliary Battery tray connector. Please note: it is spliced again and joins the PCM circuit board grounds...which are critical in their own nature...and "eventually" terminate at the negative post of the Auxiliary Battery's negative terminal.  

 

This photo is very interesting, it is the Factory Service manual and the assembly line documentation follows this as a road map in the matrix during production. Please NOTE the title "NAME" to each battery...I looked at this for a considerable amount of time before I realized the assembly line coordinators tried to work with the documentation from the Engineering Staff to "make it as it looks"...Could this single oversight be the reason of a four foot ten inch critical ground wire combination traveling the distance to "EVENTUALLY" terminate at ground? From a basic engineering standpoint regarding ground...you "NEVER CHOOSE THE PATH OF EVENTUAL GROUND" !!! 

 

It is to be the shortest and most concise connection in reference to ground...this is biblical in ALL ELECTRONICS...including pickup trucks.  !

 

Here is the Factory Service manual documenting the PCM circuit board reference ground starting as a pair of #14 gage wires being spliced into a #10 gage bundle and arriving at the Auxiliary Battery through another connector that joins a #8 gage wire that is "splice-joined" under plastic conduit in a Y configuration joining the rouge #8 gage "after passing over the alternator" traversing the entire engine compartment from the driver side of the vehicle. Seriously 

 

I have been drinking excessively, most recently, due to the nature of this blatant discovery.   

 

This is the hidden Y splice at the Auxiliary Battery where the "mess" EVENTUALLY terminates for ground reference.

 

This photo shows the correct "HOLE" of where to apply ground for the VP44, ECM and the PDC...note the logical location

 

It took a little research to find the size and proper thread-pitch.

 

Metric M5 with a 5/16" hex head is perfect

 

This is where you apply a fresh "quality" #6 gage ground and terminate this at the Main Battery negative post on the drivers side for absolute ground reference for the VP44 and ECM 

 

This is a very short and concise reference to ground.

 

This is the corrected procedure for a rather critical ground.

 

The two largest wires originally contained within the 1 inch conduit are no longer present and located well away from the alternator.

 

My alternator B+ "charge" line is now a #4 gage line directly connected to the Auxiliary Battery and when my new battery terminals arrive and they are secured, I'll provide photos of a completed Master Power Supply System within this engine bay. 

 

With these corrections, I would hypothesize that a poor ripple specification on a given alternator would be overcome by the immense capacitance of the parallel batteries and would become less prone to causing the dreaded TC lock/unlock for automatics and cruise-control abnormalities for the manual transmission platforms. 

 

The #8 gage Blk/Tan passing over the alternator as an "EVENTUAL" ground is gone...the PCM, ECM, VP44 and the PDC are now grounded in accordance of standard Electronic Engineering practices.

 

Respectfully

W-T  

Edited September 3, 20195 yr by IBMobile
spelling

I did not. I already had most of what I needed on hand. The only things I did not have was 5' of #4 wire to tie the battery grounds together with ring terminals and clamps to clamp it to the radiator. I just attached them to the bolts that hold the B+ cable. You will also need some more clamps to replace the ones on the block that will be to large after removing the charge wire to the PDC or not, your preference. I replaced the loom with smaller loom, you would not have to.They have them at Lowes cheaper than the parts store but then again I dont have to drive 40 miles to get there.

 Some of the parts depend on what you have under the hood. I have military style terminal ends with 3/8 bolts, the stock ends have 5/16 bolts. If you look over the process and then compare to what you have the list should be reasonably easy to do, though I did have to do some . I did reuse some of the wire I removed. Stripped it back and it was as shiny as it was new. Check the insulation for any damage also.

Edited May 20, 20186 yr by dripley

Did the ground mod this weekend, actually just now. Thanks a lot, I feel like it made a good difference. Lockup is a bit smoother now, but Im still getting some shuttering overall, unfortunately (even after a new TC). I put the 4 ground wires in a 6ga lug that I got at Lowes, put flux in there and used rosin core solder and a bit of map gas to solder it. That was after crimping it with a $37 hydraulic 10ton crimper from Amazon, delivered on Sunday. Then UL spec heat shrink to keep the moisture out.

 

One thing I also did was put a 4ga cable from the alternator to the aux battery, as suggested in this write up. My stock charging cable looked fried. I noticed my batteries are now reading 13.2v on my Fluke, with the truck off at rest. The truck was driven for roughly 45 minutes with this new charging cable configuration. In the past its always sat at 12.7-12.8v at rest whilst off. I keep a keen eye on my batteries and charging rates after problems in the past. Its 13.6v-13.7v whilst driving on the quadzilla/ecm readout. Perhaps the batteries are being overcharged, now?

Edited May 20, 20186 yr by rogerash0

That is pretty normal for me. It will go up in colder weather. The older the temp the higher the charge.

 

Did you by any chance check your ac voltage before and after the mod?

I did, but I didn't write it down is the problem. My instincts tell me the ac is less because the highest reading I got with the stereo on, becsuse I can't turn it off, measured at the back of the alt was .012vac. Before I tested it off the back of the alt and I got .040vac, I remember that now because it matched what the sticker spec'd out as ac ripple exactly. Only thing is I can't remember if .040vac was measured with a hot hot engine like the .012vac reading was read just now. And my batteries read the same voltage at rest in the winter and summer here. It's just when it's real cold I see up to 14.3v charging rates whilst driving. They still don't read 13v+ while at rest with the truck off. (They shouldn't, but they are now). Previous to running the new charging line they read a perfect 12.8v. I will go re-measure again now just to be sure.

Edited May 20, 20186 yr by rogerash0

I tested mine at the alt and the batteries before and after and it dropped from .035 before to .010 after. I was not expecting that. I think your diodes are already in tough shape it wont make that big a difference. I have also had my grid heaters disconnected for the past 2.5 years. Might have helped.

 

So how about anyone else that does this, check you before and after ac voltage to compare. 

My tests were done on a brand new alternator. Before and after. Its just an AutoZone special. I just took the grids off as well.

Went back and reread, missed the before and after. Mine is an AZ alt also. Put it on about 3.5 years ago when the bearings started failing in the previous one.

I did this mod yesterday as well while dodging rain drops.  I have not run a ground between each battery yet. My ac ripple was 0.03 before and 0.015 after. A big thanks to @W-T for his knowledge and brain storming this mod.

 

Been doing a lot of maintenance in the past week or so as I am driving up to NY next week.  I wanted to make sure that it's in the best shape as possible.  I do believe this will be the longest trip the Silvermoose has ever been on. My brother the po kept it local.

 

 

L8tr

D

Edited May 21, 20186 yr by SilverMoose

I need the simplified version of this write up lol

 

I’d be curious to see how much mine would drop if at all since I’ve already upgraded all my major cables.

28 minutes ago, notlimah said:

I need the simplified version of this write up lol

 

I’d be curious to see how much mine would drop if at all since I’ve already upgraded all my major cables.

I did the mod after replacing all of my stock cables. 2/0 welding cable for them all about 10 or so months ago. Did not see any drop after that until the mod. Still surprised at the drop I saw after the mod.

 

Not trying to beat anyone up but I, the president of the electrically challenged club, was able to do this without much trouble. I started, after reading @W-T post, at the alternator and just worked my way back. Did some re reading and took my time. Fairly easy, all the steps are there.

Edited May 21, 20186 yr by dripley

Thanks @dripley I’m now offended and don’t know what to do with myself!! 

 

Kidding of course! I’ll have to do the same one of these days. Last I checked my AC I was around the numbers you guys were seeing post mod so I’ll check again here soon and go from there on whether I do the mod or hold off.

 

 

3 minutes ago, notlimah said:

Thanks @dripley I’m now offended and don’t know what to do with myself!! 

 

Kidding of course! I’ll have to do the same one of these days. Last I checked my AC I was around the numbers you guys were seeing post mod so I’ll check again here soon and go from there on whether I do the mod or hold off.

 

 

No offense meant either. Took a lot of thinking for me to start cutting on the truck, but it turned out good. Good luck with your thoughts.

21 minutes ago, dripley said:

No offense meant either. Took a lot of thinking for me to start cutting on the truck, but it turned out good. Good luck with your thoughts.

 

Im just giving you a hard time @dripley! I’ll let you know how it goes once I get it done!

I finally got around to cleaning up the ground wire splices for the PCM this week end.  It's not hard and took very little time to do. 

NOTE: Do this after the other modifications have been done or you will lose the ECM, VP and grid heater grounds. 

 

You need:

2  10-12 gauge butt connectors 

2  1/4 heat shrink tube  2" long

rosin core solder 

140 watt solder gun (Weller) or small butane torch

roll of electrical tape

razer knife

wire cutters

wire striper

 

Remove air cleaner housing this will open up the whole area to work in.

No need to disconnect the batteries, just unplug the gray connector at the ground wires of the right (AUX) battery. The other gray connector has already been disconnected when the ground wires were relocated to the back of the timing cover.

Disconnect the 3 plugs at the PCM

 

Cut and strip the 8 gauge wire then cut the connector off  the 10 gauge wire and strip it back to fit the butt connector. 

 

 

This is the connection with the cove off.  This is splice #S109 that the grounds for the ECM, PCM, VP44, grid heater relay and data link connector.

 

 

Slide the heat shrink on to the wire were it won't be affected by the heat of soldering.

Remove any plastic covering on the butt connector, insert the wires into the connector and solder.  Let cool then cove with the heat shrink.  

 

 

At the PCM find the two 14 gauge black with tan stripe wires.  They go up into the split wire cover about 10" that's were you'll find splice #S126 

There are two 14 gauge black with tan strip wires coming down to the connector. One is the ground for the data link connector and the other is not used.  

 

 Repeat the cut, strip and solder process as above. 

 

When done it should look like this.

 

Nice to see that one @IBMobile. I have yet to get to it. As with the others it looks quite simple. 

 

You reckon they let @W-T retire or just chained him to his desk?  I know they tried to chain me when I went to my 20th anniversary party a couple months ago. 

Appreciate the photos.

22 minutes ago, dripley said:

As with the others it looks quite simple. 

Thanks, it's a piece of cake.

 

I tried to retire but my boss said NO!  She's using me as a tax write off.   

 

On 5/20/2018 at 3:55 PM, dripley said:

I tested mine at the alt and the batteries before and after and it dropped from .035 before to .010 after. I was not expecting that. I think your diodes are already in tough shape it wont make that big a difference. I have also had my grid heaters disconnected for the past 2.5 years. Might have helped.

 

So how about anyone else that does this, check you before and after ac voltage to compare. 

I did this mod a while back, but just got to testing it again yesterday. Results are truly amazing. I went from. 037 to.018 pretty much got cut in a half. 

Now I'm going to look for free time to do what @IBMobile did with ground splices closer to ECM.

Edited June 4, 20186 yr by JAG1

3 hours ago, Dieselfuture said:

I did this mod a while back, but just got to testing it again yesterday. Results are truly amazing. I went from. 037 to.018 pretty much got cut in a half. 

Now I'm going to look for free time to do what @IBMobile did with ground splices closer to ECM.

Me too. It seems that some yard work is getting in the way.

 

On a different note Mr DF, I got some of those Bars Leak tablets and my weeping head gasket is dry. Thanks for the link, this will buy me a little time.

Edited June 4, 20186 yr by JAG1

My Q is on IBM Mobile's grounding of the PCM, why not ground it as soon as possible to the chassis somewhere close to the PCM, instead of taking it to the battery.

Edited June 4, 20186 yr by rogerash0

1 hour ago, rogerash0 said:

My Q is on IBM Mobile's grounding of the PCM, why not ground it as soon as possible to the chassis somewhere close to the PCM, instead of taking it to the battery.

I believe because with time corrosion we'll take the best of it, and going straight to battery will minimize loss of ground. That's why I put extra ground straps throughout my truck, to bond everything together. Although it was advised against many times now seems to be a common practice. Bonding.