Large Case 370a Alternator Problem

[RR99]

Before we get started I would like to point out a few things..
My 2003 XLT 4.6L is running great, I installed a 7000 Watt audio system about 6 months ago and the lights Dimming issue was expected so next step was to upgrade the alternator..
Ordered a Large Case 370a CES Alternator built especially for my vehicle..
As CES suggested a minimum of a 1/2 shorter belt is recommended so I went a bit further and replaced the Belt Tensioner and all 3 Idler drive align pulleys while I was at it..
next would be a couple extra battery.. Well, I've not made it to the Battery upgrade..
When I install New Alternator the battery light comes on and battery voltage drops from 12.6v to 11.9v
It pretty clear it's not charging and unplugging the pigtail from the alternator has no effect on the system.. I can put the old alternator back on and everything goes back to working great..
New Alternator is in A+ running condition(Had it tested at 2 different locations), All wiring, Fuses, Pigtails, Voltage drops and relays have been tested and all are A+..
All is good and nothing is bad so my question is..
Is there a workaround to get the PCM to tell the alternator to charge which is what I think the problem is
Pretty sure someone has had this issue so any help would be appreciated..

 

[Hamfisted]

Your Expy came with a 110A alternator and everyone that tries to even go to the factory upgrade option 130A ( i.e. those with Navigation...), cause errors and "no charge" from the alternator after installation, and the complimentary "Battery" warning light. A member named "Gain-Mob" installed a dual alternator setup, so you might message him and see how he did it and what the results were. But he's got a monster sound system in his Expy.

https://www.expeditionforum.com/threads/subwoofer-amplifier-installation.39003/page-2

 

[RR99]

Thanks for the reply.. Will do

 

[GAINMOB]

what battery do you have under the hood? if it is still the oem acid battery get rid of it as soon as you can and get an AGM battery. XS Power is good to some but had many bad reviews the last few years...Full Throttle have proven themselves to be a good brand...my personal favorite is Northstar as they have the longest dissipation rate...if funds is an issue then go to autozone or advanced auto and get their agm battery. GP 65 for under the hood.

1st thing i would do is disconnect the system and take the truck to the shop to investigate any electrical problems with the truck anywhere in the truck.

when that checks out do the big 3 upgrade (add wires...not replacing)...the alt is the heart of the electrical system and it needs power to maintain so a GOOD battery and big 3 upgrade will improve current flow

i have 3-370a 15.2v Apex High Output Alternators...on the motor and the 2 aux for the audio...i'll be adding 2-3 more alts later

my bracket was fabricated by a local shop but they kept the schematics to reproduce the bracket...$900

 

[RR99]

Thanks, Big 3 done and I added not replace any wiring.. Do need to upgrade battery and was thinking of Full Throttle as you mentioned.. Sent the 370 back to CES and currently waiting on a reply..

 

[RR99]

I got the Alternator back today from CES.. Told me they put a thin back rectifier to solve the clearance problem and it did.. also said they put in a new oem regulator.. Time it was delivered I went straight to installing it and guess what?? SAME BULLSH*T AGAIN!!
Instead of explaining it all again I recorded a couple vids of the process.. I'm really pissed at this point..

 

[ribcor]

Before we get started I would like to point out a few things..
My 2003 XLT 4.6L is running great, I installed a 7000 Watt audio system about 6 months ago and the lights Dimming issue was expected so next step was to upgrade the alternator..
Ordered a Large Case 370a CES Alternator built especially for my vehicle..
As CES suggested a minimum of a 1/2 shorter belt is recommended so I went a bit further and replaced the Belt Tensioner and all 3 Idler drive align pulleys while I was at it..
next would be a couple extra battery.. Well, I've not made it to the Battery upgrade..
When I install New Alternator the battery light comes on and battery voltage drops from 12.6v to 11.9v
It pretty clear it's not charging and unplugging the pigtail from the alternator has no effect on the system.. I can put the old alternator back on and everything goes back to working great..
New Alternator is in A+ running condition(Had it tested at 2 different locations), All wiring, Fuses, Pigtails, Voltage drops and relays have been tested and all are A+..
All is good and nothing is bad so my question is..
Is there a workaround to get the PCM to tell the alternator to charge which is what I think the problem is
Pretty sure someone has had this issue so any help would be appreciated..

Did you ever get the problem fixed with your CES alt? What did you have to do to get it charging? Having the same problem with my ces 370

 

[GAINMOB]

my truck came with 130a alt...i upgraded my alt from the oem to 320a Singer alt and no more dimming...then i put in autozone agm battery...later upgraded to northstar gp 65...i swapped from oem to northstar in my ex's 2011 altima that i put 2-10s on 2k watts rms and the lights started dimming...with the oem alt i installed northstar batter and the dimming stopped...battery is critical and just as important as the alt...but you MUST know how much amperage you need to run the system...more than likely just having the stock battery isnt enough...he needs an extra batter dedicated for the 7k amp as well...i have 2 NS480AGM batteries...these are marine batteries that have a VERY LONG dissipation rate...fast recharge rate...my truck sat for 5-1/2 months...all batteries died...1 jump on the 1st try after letting the battery build a charge and it's still running strong now and its 4 yrs old