W-T ground mod

[Alexio Auditore]

Interesting. Does the sensor do anything when the temp gets to high? Like telling the computer to stop charging if it is over charging a battery?

 

That Makes sense about the monitoring for the proper abient conditions for the life of the battery. 

[JAG1]

There needs to be a way to limit the alternator charge rate so it does not get smokin' hot. What about these poor guys that spent a lot of money for an expensive alternator?

 

I might be beginning to understand this........... if one battery has a shorted cell both the alternator and the drivers battery are trying to feed this one 'bottomless pit' battery, so to speak.... now causing a never ending high charge demand from a constantly draining bank of batteries. The PCM says give it all she's got so now the poor little alternator is overworked for the duration of drive time. In my case was a 65 mile run. This has nothing to do with the battery temperature sensor, is that right?

 

There needs to be a way to save a good performing alternator under these circumstances when you have a shorted cell. The poor thing is already on the small side for our trucks.

[Mopar1973Man]

5 hours ago, Alexio Auditore said:

Does the sensor do anything when the temp gets to high?

 

Just reduce the charging voltage.

 

5 hours ago, Alexio Auditore said:

Like telling the computer to stop charging if it is over charging a battery?

 

In @JAG1 case it did nothing because the sensor is on the driver side. The passenger battery continue to boil from a shorted cell. It will on ly reduce the charge voltage to 13.2 as a low.  This might make the other battery weak if the sensor see high temps. If it see low temps then the charge rate is turned up to 14.8.

 

Even my solar/hydro system does the same thing but on a 24V scale.

1 minute ago, JAG1 said:

This has nothing to do with the battery temperature sensor, is that right?

 

Correct...

[JAG1]

Is there any way to automatically limit the charge rate in a situation where an old battery has a sudden shorted cell ? You know... kinda like me when you ask me to split firewood with no milkshake.

Edited July 24, 2020 by JAG1

[Mopar1973Man]

No. 

 

Even my solar / hydro system has the same problem. One battery goes bad it fouls the entire battery bank and all 8 batteries would need to replaced. Roughly 4,800 dollars last time.

 

As on our truck there is nothing can be done just both batteries should be replaced.

 

Hence why I like lead acid batteries because I can maintain electrolyte levels and equalize charge when needed. Ive been getting 10 to 11 years from batteries. Solar system last about 15 years.

 

As for shorted cells are from not doing equalize charge. Sulphation starts on the plate and later on flakes off and piles up in the bottom of the cells. The piled waste now shorts the cells If you do equalize charging you will bring that material back into the plate or solution and reduce the waste material.

 

DO NOT equalize charge AGM or sealed batteries it will cause venting of moisture and cause possible explosion. Lead acid batteries with removal caps are fine. Just remember to check electrolyte AFTER charging.

Edited July 24, 2020 by Mopar1973Man

[JAG1]

On 7/23/2020 at 11:43 PM, Alexio Auditore said:

Interesting. Does the sensor do anything when the temp gets to high? Like telling the computer to stop charging if it is over charging a battery?

 

That Makes sense about the monitoring for the proper abient conditions for the life of the battery. 

Very good question.... There has to be a way to prevent Thermal Run away ( I can't claim credit for that terminology), but proper strapping between the batteries makes the marriage so they both become one battery and the temp sensor will tell the Computer to lower the output. This is my understanding and is needed as a final completion to the W-T  wire Harness corrections.

 

[Mopar1973Man]

6 hours ago, JAG1 said:

There has to be a way to prevent Thermal Run away 

 

Yes there is one way. Test your batteries and replace. Period. 

 

If there was a sensor on both batteries then the batteries would be under charged because of the heat generation. Be glad in your case the battery was on the passenger side and was able to keep the driver side battery charged. If it was reverse you most likely be breaking out jumper cables. 

6 hours ago, JAG1 said:

his is my understanding and is needed as a final completion to the W-T  wire Harness corrections.

 

Already one battery WITHOUT the jumper between. Remember the block is more conductive and handles more current that any cable will. I've already proved there is only 3 to 4mV difference with or without the jumper cable.

Edited July 26, 2020 by Mopar1973Man

[JAG1]

4 hours ago, Mopar1973Man said:

 

Yes there is one way. Test your batteries and replace. Period. 

 

If there was a sensor on both batteries then the batteries would be under charged because of the heat generation. Be glad in your case the battery was on the passenger side and was able to keep the driver side battery charged. If it was reverse you most likely be breaking out jumper cables. 

 

Already one battery WITHOUT the jumper between. Remember the block is more conductive and handles more current that any cable will. I've already proved there is only 3 to 4mV difference with or without the jumper cable.

 Had my batteries tested, but the battery shop was like a used car lot so I didn't trust them.... I should have listened even tho the truck started fine, not turning over slowly and I figured what can it hurt? Well I could have not only saved an alternator, but could have lost the computer, maybe even the truck it got so smokin' hot.

 

W-T says the 3-4 mV difference is huge when compared to the charge rate.

 

I'm in this big pot of hot water, W-T is pouring in cold water, but moparman keeps adding more wood. I think it's funny, but the serious side to all this is that W-T's original , very excellent and well written thread was lost on this subject. It had excellent questions from members and really good answers from W-T. It was a great discussion, got a tremendous response. Now we have this ghost of a thread by comparison called 'W-T ground Mods'.  Another one is called, 'W-T Ground Mods Simplified'. It's not a nice thing to have your thread lost and then the information bounced around like it is . W-T put a hell of amount of time in that, deserves a lot of credit for helping everyone, but the information gets cut up and all I can do is place a small band aid here and there for him.

 

Mopar Man is the only person across the country, after all the numerous silly attempts at solving the transmission hunting and other problems, that said, ''disconnect the alternator to see if the problem goes away'' MoparMan was the only one and the first one talking about A/C noise in the system. At that point W-T began to investigate the wire harness and found a major mistake done by the factory and helped save many of us from utter frustration. W-T's contribution of significantly lowering A/C ripple and MoparMans ability to open that door, setting the direction, has been fantastic for all of us. I feel the water getting a little warmer then cooler. IBMobile get me a ladder!

 

 

Edited July 26, 2020 by JAG1

[GlasairIII]

Just did the mod.   Couple of issues.   1.  My battery gauge in the instrument cluster does not show voltage.   Shows the battery voltage for about 5 mins and then drops to zero.   2.   My passenger battery seems to be at a higher voltage than the drivers side.   By about a volt when truck is off.  With truck on, the alternator is putting out 17.5 volts.  
 

any ideas?

 

BTW.  Truck shifts so much smoother now?

Edited August 31, 2020 by GlasairIII

[dripley]

How old are batteries? They should be close,to the same with the key off. Voltage out put is way out of whack. But we need someone more versed than me for better advice.

[GlasairIII]

22 minutes ago, dripley said:

How old are batteries? They should be close,to the same with the key off. Voltage out put is way out of whack. But we need someone more versed than me for better advice.

New interstate battery’s installed 4 months ago.   

[dripley]

Could be an alternator or pcm problem. All the more reason someone electrically smarter than me needs to jump in. They will be along. It would be good if you started your own thread on the isuue. You will get better coverage that way.

[Tractorman]

1 hour ago, GlasairIII said:

 With truck on, the alternator is putting out 17.5 volts.

 

First, double check all of your work.  There could be a ground connection missing.

 

How are you checking the alternator output?  I would check voltage with the truck running at the following locations without grid heaters operating:

 

*  Negative lead to negative post on passenger side battery.  Positive lead to positive post passenger side battery.  Should be around 14 volts.

 

*  Negative lead to negative post on driver's side battery.  Positive lead to positive post driver's side battery.  Should be around 14 volts. 

 

*  Negative lead to negative post on passenger side battery.  Positive lead to alternator output post.  Should be around 14 volts (maybe .1 or.2 volts higher than battery voltage due to resistance in smaller charge wire).

 

Write down the readings and report back what you observe.

 

- John

Edited August 31, 2020 by Tractorman
I always have to edit

[JAG1]

You may need to clean the engine grounds from the batteries. They bolt down low on the engine block and that's where they get dirtier than anywhere else. Go back over all you did.

[GlasairIII]

Jag and tractor man,

 

Thanks for the advice.  I’d insert pics to make it easier to see what I’m saying, but i don’t see how?

 

Anyhow, with the truck off.

1. Measured voltage between negative and positive posts on the passenger battery = 12.79

2. Measured voltage between negative and positive post on the drivers battery = 12.52

3. Truck running and voltage measured the same way.  Passenger = 17.38 and drivers measures 12.17

4. Gauge in cabin reads same as drivers battery.

 

I did remove the passenger battery negative lead from the block.  A bit of corrosion,  Cleaned block and terminal with sandpaper and cleaned up bolt with wire brush.  This was done before the items above.

 

I have not added the additional ground wire between batteries.  And upon inspection my positive battery cable may be a bit worn.  The covering at the terminals has gone from red to brownish over the years....

 

As far as missing something during the mod.  Here’s what i did.

 

1. Removed ground cable from harness to 4 wire junction.  Took the four wires and installed a terminal.  New ground wire going from engine case as shown in the pics to the drivers battery.  Ground also has the four wires at the same location.

 

2. Removed the cable from the alternator to the PDC.  Installed shortened wire (used a piece of the original wire and installed lugs) from alternator to the passenger battery.

 

What did I miss?

 

For now, I’m driving the truck with the connector disconnected from the alternator.  (Short drive to work)

 

Thanks for the help everyone.

 

[Tractorman]

8 hours ago, GlasairIII said:

Anyhow, with the truck off.

1. Measured voltage between negative and positive posts on the passenger battery = 12.79

2. Measured voltage between negative and positive post on the drivers battery = 12.52

3. Truck running and voltage measured the same way.  Passenger = 17.38 and drivers measures 12.17

4. Gauge in cabin reads same as drivers battery.

 

It looks to me that the electrical connection between batteries has been lost.  I think that the PCM is sensing voltage from the driver's side  battery, but alternator output is only getting to the passenger side battery.  This would explain that while the truck is running, the driver's side battery voltage is falling (telling the alternator to increase the charging rate) and the passenger battery is rising (exceeding its normal limits).

 

Try using a large jumper cable and connect passenger side battery positive terminal to driver's side positive battery terminal.  Start the engine and if everything corrects itself,  you have found the problem.

 

If this doesn't not correct the problem, then do the same procedure, but only with the battery ground terminals.

 

- John

[GlasairIII]

John,

 

thanks.  That’s exactly what I’ve been thinking about. Will give a go after work.   Guessing it’s my positive lead going from batt to batt. (Additional ground has already been added going from drivers batt to engine during the w-t mod)

[Tractorman]

@GlasairIII,  you did a good job posting your test results which makes it easier to diagnose.  It also would make sense if this is the problem because before you did the W-T wiring mod, the alternator charge wire would have been charging the driver's side battery so the "problem" would have been hidden and everything would have seemed normal.

 

- John

[GlasairIII]

3 hours ago, Tractorman said:

@GlasairIII,  you did a good job posting your test results which makes it easier to diagnose.  It also would make sense if this is the problem because before you did the W-T wiring mod, the alternator charge wire would have been charging the driver's side battery so the "problem" would have been hidden and everything would have seemed normal.

 

- John

WOW. Turned out to be an easy fix......  But first how I got there.

 

Put both positive and negative leads of the jumper cables on the batteries.  Measured voltage with the truck off.  The passengers was marginally higher than the drivers.  (Slowly equalizing both batts) Hooked up the plug to the alternator. (Had it disconnected so i didn’t roast the alternator during my drives to work). Started the truck and......  Both bats where taking a charge and within .5 of a volt of each other.  The alternator slowly regulated the charge and stabilized at 14 volts.  Gauge in the cab now worked and displayed the same as the drivers batt.   Took the positive jumper off of the drivers batt = nice spark show.  Battery voltage dropped on the drivers and shot up to 17 on the passenger side.  Put the positive jumper back on and everything stabilized again.  Disconnected the negative jumper lead from the drivers batt.  No spark show and the volts on both batts stayed the same.  So what did that show me???   That the positive cable from batt to batt was failing to perform it’s sole function in life.  Shut the truck off, disconnected the jumper cables, disconnected the ground cables on both batt’s and disconnected the positive cable between both batteries.  And what did I find?  A whole lot of corrosion on the cable terminal ends and the post on the bolt for the positive terminal.  With all of this connected, unable to see the corrosion.  Wire brushed it all down and re-assembled it all.  Started the truck and.....  All is well!  

 

The bad grounds found during the W-T mod and the faulty cable from batt to batt had been masking several issues.  From funky shifting from the tranny to dead pedal of the fuel system.  I cannot thank those enough who post on this forum and offer sound advise and solid troubleshooting skills.  Without this kind of resource, you could get frustrated enough chasing problems to be rid of the vehicle.  

 

Now she’s driving better than she ever did.  And I think I’m falling in love with my truck again:)

 

Now off to go sort out my wandering steering problem:)

 

Thanks again,

Steve 

[dripley]

Very good to hear Steve.