Jump to content
  • Welcome To Mopar1973Man.Com

    We can see you lurking about Mopar1973Man.Com reading articles and reading other member's posts. Are you trying to solve a problem with your Dodge / Ram Turbo Diesel Cummins? We have lots of helpful members and staff on the Mopar1973Man.Com and are willing to give guidance on how to fix or improve your truck. You know when you see good valued information here on Mopar1973Man.Com. We are not corporate owned like many of the other websites out there. Like Cummins Forum (VerticalScope Inc.). Mopar1973Man.Com is entirely privately owned and operated since 2004. Your subscription funds goes towards server maintenance and software maintenance. We happen to be one of the most friendliest and helpful websites for Cummins Owners in the world. Come join us and register and then pick a subscription plan


Acceptable AC voltage with grid heaters on

Recommended Posts

  • Board Of Directors
19 hours ago, Mopar1973Man said:

National Weather Service Boise ID
248 AM MST Sun Nov 15 2020

West Central Mountains-Boise Mountains-Western Magic Valley-
Camas Prairie-Upper Weiser River-Baker County-
248 AM MST Sun Nov 15 2020 /148 AM PST Sun Nov 15 2020/


* WHAT...Snow expected. Total snowfall amounts of 1 to 4 inches
  are forecast at elevations between 3000 and 4500 ft, with 4 to 8
  inches from 4500 ft to 6000 ft, and 8 to 14 inches above 6000
  ft MSL.

* WHERE...Portions of eastern Oregon, west-central Idaho, and
  southwest-central Idaho.

* WHEN...Until 11 AM MST /10 AM PST/ this morning.

* IMPACTS...Travel could become very difficult.

* ADDITIONAL DETAILS...Breezy conditions will result in areas of
  blowing snow above around 7000 ft.


Slow down and use caution while traveling.

The latest road conditions can be obtained by calling 5 1 1.

How much snow did you get ?

Link to post
Share on other sites
  • Replies 41
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

My wife and I just moved into our newly built house just 10 miles northwest of Baker City.  From @Mopar1973Man' place, it is 86 miles (compass heading 251 degrees) as the crow flies - much farther if

Thank you and Dieselfuture for the kinds words. It took a little bit of work. I can assure you there are plenty of rusty, oily and sharp things still there!  Awesome pics Tractorman! Down here in

Wow,  Thank you guys. Never ceases to amaze me the amount of experience and effort people on this forum put out. I tested my new alternator full warmed up with no acc on and she holds solid at .0

Posted Images

  • Administrator

Things to think about... 

  • W-T ground wire mod really does cut back the amount of AC noise fed back to the ECM and PCM which the PCM will carry that AC noise right to the field and cause it to amplify the noise.
  • Good block and body ground are REQUIRED. If you measure above 0.2 voltage drop  from battery negative post to block replace the cable(s). There is zero need to a negative cable jumper you can test by hooking up jumper cables between both negative post and measure the voltage drop with or without the jumper if there is any change change the block and body grounds. If there is no change like my truck where the voltage drop remains 3mV DC with or without a negative jump this means that it does NOTHING and has zero benefit. Actually the block can flow way more current that a jumper cable. Hence why it does nothing. 
  • Make sure your alternator is bench tested for AC ripple. Typically a full load test will create a value around 1.0 to 1.2 Volts under full load on a test stand. If the alternator is passing on the test bench it will pass on the truck as well. 
  • Grid heaters draw way more than what the alternator can charge at an idle. Don't start your truck and leave idle to warm up at 800 RPM. This is where I typically use either Mopar1973Man high idle or the Quadzilla high idle to up the RPMs to 1,200 this increase the charge rate more, increase air movement around the diodes keeping them cooler. Reduced the stress on the alternator.
  • Bad battery cables are far more common than you think. Voltage drop test is a excellent way to verify cables and terminals for good function. Being you testing under the high loads. 
  • "Black" terminal is a lead that is oxidizing, typically a positive post. Engine oil helps reduce the amount of air contact and the acid contact on the terminals. Terminals need to have that fresh lead appearance. Lead oxide is will resist current flow, typically creates warmth to heat at that spot too. Running you hand over terminals careful and wire if you feel heat that cable is failing. 
  • Bad rotor brushes in the alternator can create AC noise as well. Some local shops could do the replacement in just like 15 minutes and retest for AC noise. (DuroBuilt, Nampa ID) - Thank @AH64ID 
  • Consider reducing total loads on the electrical system. Like I've done HID headlights which are only 35w for both. Driving lights are 18 for both. Previous light was four 100w flood lights and halogen bulbs (45w /65w). LED's are fraction of the electrical load. Look at other stuff like blower motor too if you fan only work on high the bearing are gone and the blower resistor over heated and blew out. Replace both and you'll reduce you electrical loads there. Disconnect the grid heater if you in warm climate and don't require them. 
  • Like 3
Link to post
Share on other sites
  • Board Of Directors
2 hours ago, Mopar1973Man said:

Bad rotor brushes in the alternator can create AC noise as well. Some local shops could do the replacement in just like 15 minutes and retest for AC noise.


You can replace them yourself,  It's a very easy job,




  • Like 1
  • Thanks 1
Link to post
Share on other sites


Thank you guys. Never ceases to amaze me the amount of experience and effort people on this forum put out. I tested my new alternator full warmed up with no acc on and she holds solid at .03. That seems acceptable.


Just to add some detail, I was having a bad misfire when I got up to about 45mph. Previously I had changed out a bad vp44 for a DAP unit, and I also had a totally blown up ecu just prior to that, most likely from either a bad ground or the bad alternator I just switched out. In any case, I had been chasing my tail because I had no codes whatsoever and was beginning to doubt the new ecu, or think the apps was going. It almost felt like the vp44 was turning off and on. 

Up to this point I had

-Done the WT mod

-Changed the apps over to a timbo 

-Verified wiring integrity ad nauseum 

-Changed alternator

(The apps and the alt needed to be changed regardless, so I didn't waste any money)

And my whole charging cable system is pretty bomb proof, all marine 2/0 tinned lugs, mil terminals etc.


Welp, yesterday I found the culprit. See pic below. The #2 injector tube got buggarred somehow. Some junk mustve got into the line nut the when I changed the vp. Dont know how, I'm pretty good about cleaning things that touch sensitive things. It was hiding behind the air horn and weeping just enough fuel to not be noticeable. Luckily I had a spare set of injector tunes and sanded the flare very lightly with some 1300 grit. Sealed right up and runs like a raped ape now.

The irony of the whole affair is if someone had the same symptoms and asked for my advice the first thing out of my mouth would've been, "you're getting air in your lines somehow"

So, thats my Slingblade moment. "It aint got no gas in it"

Btw, Mike, I did consider Durability in Nampa. There is usually a pretty decent fish and chips food truck parked there, too! I just wanted to try thr off the shelf option of the 160a Durango hairpin. Seems to be working pretty well so far!





Edited by JHFIII
  • Like 3
Link to post
Share on other sites
  • Create New...