Voltage Regulator Failure

[RollTide1126]

The other day I got a message indicating I needed to service the electronic braking system on my 2016 3500 SRW 4x4 (48k). The message quickly disappeared so I didn’t think much of it. Well low and behold I got this message again after every subsequent start-up and each time the message went away almost immediately. I also started noticing the radio screen took longer than normal to come on. I did some research and found that I may have a bad battery so I took it to my local auto.parts store and had them tested. Both batteries are good but when the tested the alternator it indicated I had a voltage regulator failure. Not sure what effect this is having on the charging system because its showing 14 volts on the dash display. I’m thinking my only option is a new ECM so I called my dealer who told me a new ECM is going to run me $2200 plus a programming fee. I found some remanufactured units online anywhere from $500-$1000. Any thoughts on how I should proceed? I would appreciate any input.

 

[Learjet]

so you are saying the ECM controls alternator voltage and you are not under warranty for this problem?

 

[RVTRKN]

I'm suspecting that very issue with my 07 C&C. However it will take any where from 1 to 20 seconds for the voltage to increase to the alternator output voltage. Also my lights will twinkle for the first 10 minutes sometimes. I've done some experimenting by fully charging my batteries with some success. Its worse with the grid heater cycling, that will really effect it. So at first I thought the batteries might be a little weak, but they are only two years old and will hold a charge. One of the phenomena of it will go from 13.9 to 14.5 VDC with a 1 second cycle. I believe the ECM regulates the voltage, which is why I'm suspecting the ECM. So far its only annoying and hoping it will not get worse. FWIW, the alternator was replaced under a recall in 2017.

 

[Wayne M.]

You don’t have a regulator. The PCM controls the alt field.
You say you’re showing 14v. Where do you see this? I don’t think you have a charging problem. Have you modified the electrical system? Lights? Amps? Accessories, etc?

 

[LandShark]

Dash voltage display is not a good way to diagnose an electrical problem, Put a real VOM on the battery and check it with the truck both off and running and report back.
14 volts tells me that the battery is getting charged, at least a bit.

 

[TCDiesel]

The ECM does NOT need replacing.....Update all the module, and re-flash the ECM/PCM, problem solved, I also have installed Solar charger on all My trucks that sit for longer than a couple of Days.. All My power woe's have vacated My life......YeY.

The unit sits on the dash, You need at least 12W solar charger.

The Battery detection software is the problem....

 

[TCDiesel]

Rolltide, How far are You form Blaine MN?

 

[RollTide1126]

so you are saying the ECM controls alternator voltage and you are not under warranty for this problem?

I was wondering the same thing, when I inquired at my local dealer service department I was told it was not covered under the 6yr/100,000 mile drivetrain warranty...I didn’t have time last night to argue it over the phone. I was planning on calling another dealer today.

 

[RollTide1126]

You don’t have a regulator. The PCM controls the alt field.
You say you’re showing 14v. Where do you see this? I don’t think you have a charging problem. Have you modified the electrical system? Lights? Amps? Accessories, etc?

The truck is bone stock, no mods. I’m seeing the volt reading on the dash info screen.

 

[RollTide1126]

Rolltide, How far are You form Blaine MN?

Far...Southern California

 

[RVTRKN]

The ECM does NOT need replacing.....Update all the module, and re-flash the ECM/PCM, problem solved, I also have installed Solar charger on all My trucks that sit for longer than a couple of Days.. All My power woe's have vacated My life......YeY.

The unit sits on the dash, You need at least 12W solar charger.

The Battery detection software is the problem....

Can you provide a link to that solar charger, my truck can sit for awhile? I only have 75K on my 07 C&C.

 

[TCDiesel]

Bummer on the distance.. I will provide link on the Charger, You will need to Make your own leads and connections, the ones the Solar panel comes with are very Poor and NOT permanent.

 

[RollTide1126]

Dash voltage display is not a good way to diagnose an electrical problem, Put a real VOM on the battery and check it with the truck both off and running and report back.
14 volts tells me that the battery is getting charged, at least a bit.

Will do

 

[RVTRKN]

TC, do you plug it in to the Cigar lighter, and had to fabricate the connections?

 

[TCDiesel]

TC, do you plug it in to the Cigar lighter, and had to fabricate the connections?

No.. I have to go Right Now, I will post link and pictures later...Others will mostly jump in also.

 

[RollTide1126]

Dash voltage display is not a good way to diagnose an electrical problem, Put a real VOM on the battery and check it with the truck both off and running and report back.
14 volts tells me that the battery is getting charged, at least a bit.

Ok, I went out this morning to test the batteries and they read 12.4 & 12.3 respectively. I wanted to test the alternator, the radio and dash lights came on but the truck didn’t even turn over. Re-checked the batteries and now they’re both dead.

 

[lpennock]

Have you tried really good cleaning of your connections, especially the crossover cable ends? Bad connections can wreck havoc on the charging operation.

 

[RollTide1126]

Have you tried really good cleaning of your connections, especially the crossover cable ends? Bad connections can wreck havoc on the charging operation.

I did and all the connections are clean

 

[Wayne M.]

The truck is bone stock, no mods. I’m seeing the volt reading on the dash info screen.

I’m with TC. Probably needs a flash. The battery tender might be a good idea, but if the flash fixes the battery management, that’s what you need. If you have to pay a small ransom, do it! Unfortunately this is where ALL vehicles are going nowadays.

 

[JR]

Ok, I went out this morning to test the batteries and they read 12.4 & 12.3 respectively. I wanted to test the alternator, the radio and dash lights came on but the truck didn’t even turn over. Re-checked the batteries and now they’re both dead.

Did you test them individually with the crossover cable disconnected. Otherwise you will get an inaccurate reading. 12.3 volts is only about 50% charged, if your readings are with the batteries connected it's possible one is TU and you are only seeing voltage from the good one.