Does the pcm control the alternator

[syntaxterror]

2000 3800 444e

Does the pcm control the alternator? At idle the read out shows 13 volts but as the rpm's go up the reading goes down to low 12 volts.The alternator is three years old but with little use. I haven't been able to use or work on the bus for a couple years on e regular basis.

[cadillackid]

it does not... there are several types of alternators on these... most are pretty close to GN style 'SI' with a sense lead and a power lead to power on the regulator... its possible you have a dying alternator.. on a T444E when the RPM's go up you have more injectors firing more often so there is more electrical load on the system as a whole mainly from the IDM.

[syntaxterror]

Thanks i will check the wiring. I replaced the batteries about a year ago but only put 50 miles on it .

[syntaxterror]

Looking for an upgraded alternator for future improvements like an inverter.I am looking at this 200 amp.
https://www.rockauto.com/en/moreinfo...12&jsn=456bosh unit.

Would this work or should I go bigger and would it be an issue if i don't have the inverter installed yet? The inverter will run a 120 volt fridge when not on shor power.

[flattracker]

I experienced an alternator failure with the same symptoms some years back. Replace the alternator. The bast solution for extra power for an RV conversion is a second alternator is it can be done. I added a Load Boss 250 Amp alternator to the New Crown that works very well. Keeping the original electrical system of your bus isolated is the best way. It was designed to run a school bus not a vehicle to live in.

[cadillackid]

Originally Posted by syntaxterror

Looking for an upgraded alternator for future improvements like an inverter.I am looking at this 200 amp.
https://www.rockauto.com/en/moreinfo...12&jsn=456bosh unit.

Would this work or should I go bigger and would it be an issue if i don't have the inverter installed yet? The inverter will run a 120 volt fridge when not on shor power.

been using these for years..bosch SB200 I have ine on my DEV bus... put it on in 2016.. still goes strong.. it can be set up as single wire or wit ha sense wire.. they are designed for school busses, have a fairly low RPM turn on and produce a good amount of juice at lower RPM...


a fridge wont pull that many amps... I regularly pull a bunch from mine.. in winter i'll sit parked for several hours or more wit hmy diesel heater on and several inside bus heater fans.. along with my network system and the stereo and some lights if its dark... i use the alterntor to recharge when i take off.. in summer I run with 2 A/C compressors, 2 3 fan condensers, and 3 indoor evaporators running.. (engine driven A/C).. thats quite a few amps.. it cant keep up at idle but just above idle it does just fine.