My truck is now on its 3rd alternator since getting the truck last September. Previous owner a friend of mine put one in and it died on me about 3 months in and was under warranty. Second one lasted until yesterday morning was about 50-60 degrees out started the truck the check gauges light stayed on for 20 seconds or so then came up to 14v drove 20 seconds up the street and it dropped back down so I pulled over and the alternator was smoking hot and litterally smoking. Never came back up to 14v still spins freely. Ended up getting another on under warranty at orileys. I think they are the ultima brand i can find out though. What gives though? Truck was fine yesterday and all of a sudden the alternator shits it self on start up?? I read a comment mopar man made about cold weather starting and the alternator not liking it due to low rpm and the grid heaters sucking the life out of it. What's the best thing to do to keep this thing alive? Will plugging it in over night help? I usually do all winter but thinking I should start sooner. I also know a lot of guys like the denso alternators with the external regulator mod. I also did the 7.5amp fuse mod as precaution for all these alternator failures

Give us some repair history on your electrical system.  How old are the batteries?  Have you verified that all battery and ground connections are good?  How about the crossover cable?  Have you done the W-T wiring modification?  OEM wiring charges the driver side battery - the W-T wiring modification charges the passenger side battery.

 

I personally don't trust over-the-counter re-manufactured electrical parts.  They can be problematic regarding quality.  If I wanted an alternator or starter rebuilt, I would use a quality Auto Electrical shop in the vicinity.

 

The Bosch and Denso alternators are of excellent quality.  The Bosch alternator (the original still controlled by the PCM) on my truck is pushing 400,000 miles with only replacing  alternator bearings and brushes. 

 

When you do replace this alternator (I think you already have), be sure to monitor voltage at both batteries, don't just rely on the dash voltmeter.  I would disconnect the grid intake heaters temporarily just to help with the diagnosis. 

 

3 hours ago, daav544 said:

I read a comment mopar man made about cold weather starting and the alternator not liking it due to low rpm and the grid heaters sucking the life out of it. What's the best thing to do to keep this thing alive? Will plugging it in over night help? I usually do all winter but thinking I should start sooner

 

It is not necessary to take any of these precautions.   Even when you do plug it in overnight, the grid heaters will still post cycle for a period of time after the engine is started.   A new Bosch or Denso alternator will easily last 200,000 miles under these conditions.

 

Even though it is not necessary, I have installed a manual momentary switch to operate the grid heaters on my truck.  I did this to reduce the electrical load on the alternator and because grid heater operation isn't necessary 90 per cent of the time for starting the truck, or for post cycling after the engine is running.

 

- John

Edited September 16, 2024Sep 16 by Tractorman

How did you install this switch and what kind of switch is it i would like to do something like this to help keep this thing alive

And what actually is the operating sequence of the grid heater?  When do they come on and off

1 hour ago, daav544 said:

How did you install this switch and what kind of switch is it

 

I just used a switch that I had laying around.  A push button momentary switch would work well.  Place it where it is convenient to use.  The switch can be light duty, as it only operates the coil portion of the intake heater relays (less than 500 milliamps of current).

 

I disconnected terminal # 1 (OR/BK wire) on relay # 2 and terminal # 3 (YL/BK wire) on relay # 1.   I sealed and taped the ends to protect them for future use.  I provided a light gauge wire (18 gauge) from an unswitched source, through a 5 amp fuse, and then to the momentary control switch.  From this switch, I continued with the 18 gauge wire to the coils of both intake heater relays.  Wired this way does set DTC P0380 and P0382, but it does not illuminate the MIL. 

 

From this point on, you can be the boss and use the intake heaters when you feel it is necessary.

 

 

1 hour ago, daav544 said:

And what actually is the operating sequence of the grid heater?  When do they come on and off 

 

The ECM controls when the intake heaters operate.  If the ambient air temperature falls below 60° F, then the ECM will command both intake heaters to operate for a determined amount of time when the ignition switch is turned on.  After the engine is started, the ECM will cycle the intake heaters (one at a time alternately - called post cycling) until either the vehicle speed exceeds 20-25 mph, or engine coolant temperature reaches a specific value. 

 

The air intake heaters exist primarily for emissions and occasionally they are needed to assist in starting a very cold engine.

 

- John

Also is there a fuse or anything I could disconnect or the time being that would disable the grid heater complete until I get around to wiring a switch like that? Kinda disappointed after hearing all this and what the g is heaters use for power that i didn't opt for a more powerful alternator, 135a just does not seem like it's enough for these things 200a minimum in my eyes seems like what they should have done from the factory. I think even my 2004 v6 Silverado had a more powerful alternator and it was the base model lol

5 hours ago, daav544 said:

Also is there a fuse or anything I could disconnect or the time being that would disable the grid heater complete until I get around to wiring a switch like that?

 

No fuse, but you can simply disconnect the two heavy wires that feed each intake heater.  Disconnect them at the positive terminal on the driver side battery.

 

5 hours ago, daav544 said:

Kinda disappointed after hearing all this and what the g is heaters use for power that i didn't opt for a more powerful alternator, 135a just does not seem like it's enough for these things 200a minimum in my eyes seems like what they should have done from the factory.

 

I will repeat what I said in one of my previous posts, "The Bosch and Denso alternators are of excellent quality."  The same goes for the Denso Starters. 

 

Unfortunately, many people don't realize the value of these OEM alternators and starters in terms of a long dependable life.  The first sign of an electrical problem has them purchasing a cheaper re-manufactured alternator or starter from a chain auto parts store.  From there, it usually goes downhill.  Those re-manufactured components are usually of mediocre quality at best.  The worst part of the transaction is that the truck owner is giving up a quality component in trade for a not-so-quality component under the guise of "lifetime warranty".

 

So, either one of two things are happening in your case.  You are getting poorly re-manufactured alternators, or you have a serious electrical problem that needs to be addressed. 

 

I would recommend checking the condition of all your battery connections - positive and negative.  And, check the condition of the crossover cable.  Just because an electrical connection is tight does not mean that the connection is good electrically.  There could be corrosion that is not visible until the connection is taken apart. 

 

- John

 

 

 

 

Edited September 22, 2024Sep 22 by Tractorman

Question regarding types of alternators, so i found an alternator on marketplace brand new in the box for 50 bucks the part number is R110290B and mine is R111017B. The R110290B on orileys website says it fits 2001-2002 24v cummins. What's the difference between and 01-02 alternator and the previous years alternators? My trucks a 99 i was hoping to be able to buy this one I found just to keep as a back up on long trips

I think some had plug in connector on back vs. Studs and nuts.

this is what the back of the alternator looks like so I don't see why it wouldn't work it has the stud for the battery wire and the plug that looks the same as mine

This is the one on my truck shown on orileys and its specs, its a nippodenso

And this one is the one on market place the guy is selling for wicked cheap new in the box, from the looks of it i think its just the fact they went from nippodenso to bosch for the 01-02 years. I heard the Bosch ones are the ones everyone wants cus there quality

It should work.  I'd buy it and have it bench tested as a 99 Ram.  All you have to lose is $50+shipping.    

No shipping, guys local to me, and I figured for 50 bucks it's new in the box remanufactured Bosch, if it saves my *** on the road one day it's paid for itself

Personally, I like the ND alternator over the Bosch alternator because you can rebuild the ND really easy and way cheaper. Diode packs are super cheap if you know where to get them. Bearings and brushes are cheap too. Either a reman'ed or new alternator make sure to have it tested before you leave the store. I've seen brand NEW alternators dead in the box and never been used. 

 

The second thing is to do the W-T ground wire mod.

 

Alternators last much longer after this fix. No more failing diodes and burned-up brushes. 

 

Then you need the PCM protection fuse mod.

 

I have already done the w/t ground mod as well as added a 7.5 amp fuse on the blue wire going to the PCM from the alternator. My truck has a reman ND from orileys i believe the brand is ultima. And I have a Bosch that supposedly fits 01-02 trucks, i believe either will work from what I've read they just switched to Bosch during those years,the plugs are both the same on them and all the mount holes are the same. Im just guna keep this Bosch in the truck as a just in case, i wana put together a little save my *** box and have it in my truck all the time, i have the alternator, another belt, tire repair stuff, brake line repair stuff, I'm going to buy a cheap lift pump off Amazon, its 140gph and supply's 14psi. Any other things you guys could think of that could keep you from being stuck on the side of the road? Cam sensor? Crank sensor?(Is there even one?)

Radiator and heater hoses and I have a Timbo app under the back seat.

12 hours ago, IBMobile said:

Radiator and heater hoses and I have a Timbo app under the back seat.

Better add that extra VP44 so you can actually leave Idaho. 

Yes, I thought about adding one to the list.   Mike's referring to the time my VP44 took a dump about 20miles from his house and he graciously ordered one from DAP, then came out and helped me change it.