Alternator outputting 14.5v on 6.7 Cummins

[bigblock_doc]

Also check your grid heater and solenoids for proper timing, and the bolt.

 

[Dusty]

Does anyone think what battery type ,AGM or lead acid , might make a difference ?

Yes. The unknown factor here is the condition of the batteries. Don't AGMs require a different charging voltage?

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 141111 miles.

 

[crackerjack1957]

I have a 2014 Ram 1500 Hemi 5.7 & 2014 Jeep Cherokee 3.2
Factory acid batteries when vehicles were new.
Changed both to AGM batteries 4 years ago.
Both still charge with the same voltage.

That 3.2 Pentastar uses same size battery as the Hemi 5.7.......LoL

 

[nlambert182]

The batteries are brand new and have been load tested. This is the same condition that it had prior to changing over from lead acid to AGM. Swapping the batteries didn't solve anything (though that isn't why I changed them anyhow).

I'll see if i can get a multimeter down in there to measure output voltage. Oddly enough, it's been about a week and a half with no light.

 

[nlambert182]

Also check your grid heater and solenoids for proper timing, and the bolt.

Grid heater bolt is fine. Grid heater is still functioning as intended. It will happen in the middle of summer in 100 degree weather, and will happen in 30 degree weather. I don't think this is a grid heater issue either.

 

[nlambert182]

Finally had some time to check it, but of course the light hasn't came on since the weather cooled off. I'm getting 15.3V at the alternator, so the monitor is fairly close. I suppose it's just getting regulated down to what is needed at the batteries, and the light's coming on when the alternator is outputting voltage below the threshold limit that the ECM is expecting to see. I'm going to try to wait and catch it when it happens again and recheck it.

 

[crash68]

@nlambert182 I wonder if the alternator/charging light is coming on due to a flakey Integrated Battery Sensor (it's located on the battery negative terminal). This feedsback information to the ECM to control the charging voltage.

 

[nlambert182]

It very well could be... I wish it would do it again so I could start putting a meter on all of the points to check. It's playing nice right now.

 

[nlambert182]

It's been down in the 30s and 40s for the past week so no light. Got up to 68 here yesterday and it did it again. Finally got some pics. I was out in town, so no meter with me. When I restarted the truck at home, it was back to normal. No light this morning.



First pic is with the batt light on. Second is how it should be.

 

[mdc1990zr1]

@nlambert182 I wonder if the alternator/charging light is coming on due to a flakey Integrated Battery Sensor (it's located on the battery negative terminal). This feedsback information to the ECM to control the charging voltage.

I’m not sure about the RAM, but in some of my other Chrysler vehicles, especially my 2000 Wrangler, there is a temperature sensor in the battery tray. This temperature sensor figures in the charging algorithm of the regulator. Maybe a faulty temperature sensor?

 

[turkeybird56]

I’m not sure about the RAM, but in some of my other Chrysler vehicles, especially my 2000 Wrangler, there is a temperature sensor in the battery tray. This temperature sensor figures in the charging algorithm of the regulator. Maybe a faulty temperature sensor?

The temp sensor is now part of the IBS.

 

[Grams]

Yes. The unknown factor here is the condition of the batteries. Don't AGMs require a different charging voltage?

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, 18” wheels. Build Date: 3 June 2018. Now at 141111 miles.

That is a subject which always fascinates me. The AGM battery mfr’s all want everyone to Buy their batteries…..because they are So Good….
Then they break the news that their batteries also need Special Chargers! …or they’ll be destroyed.

Then one day it hit me: My 1953 airplane was created with a 12v Generator controlled by a Vibrating-Points Regulator….. the Standard Aviaiton-Technology of the 1950’s ..which used flooded-cell, lead-acid batteries and vacuum-tube avionics.

Along comes the 21st century and AGM battery mfr’s push their batteries …complete with FAA-Approval …which has the highest standards of safety aviation can offer…. as “exact replacement” batteries for 1953 airplanes….
And subsequently, the AGM guys and the Battery-Tender guys begin a campaign telling AGM battery converts how Absolutely ONLY Special Battery Chargers and Maintainers with sophisticated solid-state re-charge-programming MUST be used with these “modern technology AGMs”

The owners then rush-out and spend hundred$ of dollar$ on special chargers and maintainers….. Completely Forgetting that the Entire Time they are IN-FLIGHT that 1950’s generator and Vibrating-points regulator are keeping them “safely” in-flight.

I have Ten vehicles here on the ranch, seven of which have lead-acid and three of which have AGMs and ALL of them use the exact same El-Cheapo chargers and maintainers….and the two airplanes in the hangar ..one with a modern solid-state alternator conversion and the other with the same, old 1950s generator and vibrating regulator….. both of which have 5-yr old AGMs in them which start and run weekly without being damaged.

Doh


.

 

[Grams]

They also fly:

 

[nlambert182]

FINALLY SOLVED IT.... about two months ago. I decided to fire the parts cannon and just install a new alternator. When I pulled back the boot for the power cable to the alternator everything felt tight and looked fine, but the second i stuck a wrench on the nut, the stud broke off in my hand. I'm talking almost zero pressure on it. I could see that it had been arcing for some time once I could see behind it.

Swapped in a new alternator and it holds a perfect 13.6V consistently. Light hasn't been back on since and the truck actually runs better. Oddly enough it even shifts better, so wondering if maybe the voltage fluctuations were having some impact on some of the modules. Either way, problem solved.

 

[RamDiver]

FINALLY SOLVED IT.... about two months ago. I decided to fire the parts cannon and just install a new alternator. When I pulled back the boot for the power cable to the alternator everything felt tight and looked fine, but the second i stuck a wrench on the nut, the stud broke off in my hand. I'm talking almost zero pressure on it. I could see that it had been arcing for some time once I could see behind it.

Swapped in a new alternator and it holds a perfect 13.6V consistently. Light hasn't been back on since and the truck actually runs better. Oddly enough it even shifts better, so wondering if maybe the voltage fluctuations were having some impact on some of the modules. Either way, problem solved.

Glad to hear you have that sorted out, and thanks for the update.

For future reference, I believe that voltage drop testing may have revealed this fault.

.