2000 American Cruiser Dodge Ram 3500 5.9 360 HP Charging Problems

[ewaynebaum]

I have a charging or wiring problem that maybe someone can help. The charge rate is around 10 - 11 amps. It never goes higher, instead, as the RPM is raised on the engine the charge rate drops to zero by gauge. Turn the key off and restart, the charge rate remains 10-11 after running a few minutes the gauge drops to zero. This process can be repeated over and over.
What I have Done - Replaced all batteries, Tried three different alternators rated at 136 Amp, replaced the PCM, and replaced the battery ground wire.
Questions -I'm at a loss as to what to do, any comments or suggestions from anyone?
Also, does anyone have wiring schematics for both coach and engine?

 

[booster]

I have a charging or wiring problem that maybe someone can help. The charge rate is around 10 - 11 amps. It never goes higher, instead, as the RPM is raised on the engine the charge rate drops to zero by gauge. Turn the key off and restart, the charge rate remains 10-11 after running a few minutes the gauge drops to zero. This process can be repeated over and over.
What I have Done - Replaced all batteries, Tried three different alternators rated at 136 Amp, replaced the PCM, and replaced the battery ground wire.
Questions -I'm at a loss as to what to do, any comments or suggestions from anyone?
Also, does anyone have wiring schematics for both coach and engine?

I think you need to get some information on what the voltage is doing, instead of the amps.

The voltage at the alternator, before and after the isolator, at the batteries themselves, will tell us a lot more of what if going on and where to look for the problem, I think.

 

[ewaynebaum]

Booster thanks for your reply. I was actually measuring voltage and not amps so I misstated in my original post. I think I have found the batteries isolator. I traced from the coach batteries and the wire coming from the alternator. The third wire goes to the engine battery, I assume.
The isolated is located with no access without removing the grill. I will get the voltage readings and post afterwards. Thanks all help is appreciated.

 

[booster]

Is the low voltage only at the coach batteries and not at the engine?

If so, you need to look at the wiring to the coach batteries and the isolator for bad connections or failure.

An often overlooked area is how the coach current gets back to the alternator on ground side. The drivetrain is often fairly isolated from the body and frame and connected by a flexible link from the frame to the engine. I don't have experience with your van and model to know if you have such a connection or where it is if you do. Same is true for the connection from the coach batteries to frame. Best to check for voltage between the body and the negative of the battery.

 

[ewaynebaum]

Take a look, I think you have identified the problem. The isolator. Obviously the bolts twisted off so I couldn’t clean the isolater connections. I have a new one on order due April 4-10.
I will be able to test everything once it’s in hand.

 

[Johnnyfry]

Noting the cracking on the Isolator body, it would appear that has probably died. You can effect an emergency temporary repair by connecting all the fat wires together an one of the posts. This will allow the alternator to charge both batteries and you can operate normally. The one problem you will have with this arrangement is that the batteries are no longer isolated from each other and they will discharge in tandem so you have to be careful when operating off grid not to dischage the batteries too far!

 

[ewaynebaum]

The new isolator arrived. Made all connections and still the same thing. Low charging and falling to zero. What a disappointment. Any other suggestions?

 

[GeorgeRad]

I have a charging or wiring problem that maybe someone can help. The charge rate is around 10 - 11 amps. It never goes higher, instead, as the RPM is raised on the engine the charge rate drops to zero by gauge. Turn the key off and restart, the charge rate remains 10-11 after running a few minutes the gauge drops to zero. This process can be repeated over and over.
What I have Done - Replaced all batteries, Tried three different alternators rated at 136 Amp, replaced the PCM, and replaced the battery ground wire.
Questions -I'm at a loss as to what to do, any comments or suggestions from anyone?
Also, does anyone have wiring schematics for both coach and engine?

are 10-11 amps or volts? Is voltage going to zero ar amperage?

 

[wmgeorge]

The new isolator arrived. Made all connections and still the same thing. Low charging and falling to zero. What a disappointment. Any other suggestions?

I hope you cleaned up or replaced those lugs on the wires connecting they look terrible. What amp gauge are you using? Have you tried another amp meter inline with the alternator output wire? Do you have a good ground wire directly from the engine to the frame of the vehicle and is the connection point clean? Last after all the above, where are you getting your alternators from? The rebuilt ones can be Chinese cr@p and even three in the row from the same source could be bad.

 

[ewaynebaum]

I finally got the charge rate to over 14. I took jumper cables one side to battery and the other end to the alternator wire to the isolator, unconnected from the isolator. I left the battery post disconnected at the isolator. The charge was 14 on the gauge. This told me there was power loss going from the battery to the isolator. Replaced the cable from battery to isolator and now charging 14. Thanks to everyone. I hope this is a fix!

 

[wmgeorge]

I finally got the charge rate to over 14. I took jumper cables one side to battery and the other end to the alternator wire to the isolator, unconnected from the isolator. I left the battery post disconnected at the isolator. The charge was 14 on the gauge. This told me there was power loss going from the battery to the isolator. Replaced the cable from battery to isolator and now charging 14. Thanks to everyone. I hope this is a fix!

Now I am confused. Are you talking about the ammeter or voltage? If the batteries are low the ammeter could show 20-30 AMPs or more. With those terrible looking connections on those cables you show, yes the lugs and wire I am surprised anything could work right. Yes I am an electrician among other things and I know what I am seeing.

 

[ewaynebaum]

no all you are seeing has been replaced. The Isolator and battery wire. Everything is new. Sorry I mentioned that earlier but failed to say it in my last text.

 

[wmgeorge]

no all you are seeing has been replaced. The Isolator and battery wire. Everything is new. Sorry I mentioned that earlier but failed to say it in my last text.

Here is a picture of my dash gauges on my 2008, does your battery gauge look like this one upper right side? If so its a Volt meter.

 

[ewaynebaum]

Yes it looks like that. So I’m measuring 14 volts by gauge.