Help!! My amp gauge started going below half while ideling and then it will go back up when I accelerate when my blower resistor went out. I replaced resistor, batery,alternator, and setpentine belt and its still doing it. If I'm stopped at a light with the heat on or lights on the amp gauge will fall below half then when I accelerate or put the truck in park it will go back to a little past half again. Any ideas? No one can seem to figure it out. It's doing it worst now after I had new alternator and belt put on today.

 

Need more info on the year. Assuming it's a gen4, try this cluster self test first.

https://dodgeforum.com/forum/4th-gen...st-09-ram.html

If it passes, and assuming that the problem only shows up when the blower motor is on, then you better make sure that you used the right resistor value, resistance and wattage. Resistors of the wrong wattage (too little) will warm up and the value can change dramatically over temperature. Have you put a voltmeter on the battery when the problem is happening? What values are you getting with the blower on and with the blower off. This should not be that difficult to trace. Just throwing parts at it only confuses the issue.

 

It's a 2008 4.7 lone star. Idk I'm frustrated. I bought the resistor the part store gave me according to the model and engine size. I took it back to the shop yesterday and was told its normal. That the battery and alt are new and the battery is overcharged so it will do that for a while to protect the alt. idk if I buy that however. Since the resistor first went out this is the 2nd batery and after I put the new resistor on and it kept giving me problems I had to have a new alt and I went on and had a new serp belt put on as well. According to the shop that did the repair everything checks out fine. But it's never fluncuated like this before all this happened. It's a 2008 lone star 4.7 liter v8 with 164,000 miles other than this problem I can complain this has been the best truck iv ever owned iv had fords and Chevys and this one beats them all by far. Just getting frustrated with this and I don't believe it's normal however today it's somewhat better

 

Even with the blower off it still fluncuates now if I turn the headlamps on idk if I mentioned that

 

Yes that test worked all the gauges moved however with the ign in the on position the amp gauge is setting on about 13 amps is this normal? Or should it be all the way down like the other gauges?

 

This is the Gen4 forum and you have a gen3. Maybe if you post there, you'll find someone else that has had this issue. Gen4s have a different cluster so no one here will be able to tell you if yours is behaving correctly by displaying 13 volts (not amps) when the ign is on. If the volmeter was acting correctly before, and it isn't now, then there is something wrong. Fluctuating voltages usually indicate that the rectifying diodes in the voltage regulator are blown.

 

I would check my grounds for the charging system, make sure your battery connections are clean. Check your ballast resistor. It is possible you may have a problem with your ECM, pretty sure most of the monitoring and handling of the system goes through it.

 

Ok sorry I hit 3rd gen idk why it posted on the 4th gen forum