Ranger Mods

Hi
I have a 2012 PX1. BMS is disabled (checked with forscan), brand new ford alternator, new battery. I have an ultra gauge and on startup I might get ~13.5v while driving for a while, it will then drop to ~12.5v.
Tried unplugging the wire to the shunt on negative terminal as well but still the same.

With the BMS disabled shouldn’t I be getting a constant voltage feed out of the alternator? It’s almost as if the BMS is somehow still controlling the alternator output even though it’s disabled. Is this somehow possible?

Cheers John

I would expect that the alternator still has temperature compensation like a traditional setup. Higher temps = lower voltage, although 12.5 is a touch low. Make sure to measure the voltage at the battery for a true reading.

Thank you. Yes I have been confirming with a multimeter across the battery and the ultra gauge reading is slightly lower but follows the same pattern.

Took it for a run this morning and if I start it with headlights on and keep on it will stay above 14v. Headlights off and will start around 14v, drop to 13.5v then after five or so minutes go to around 12.5v. It just seems like it’s behaving as if the BMS is enabled but in Forscan is showing it’s disabled. Is that possible? Could the BCM be bad causing this?

I have noticed the drop in voltages quicker on hot days so maybe that is something to check. Do you know Where the temperature sensor the alternator use's is located? It’s a brand new ford supplied alternator.

Thanks again for the comments.

Not advisable to unplug like that, throws many errors

Topgear wrote: ↑Sat Nov 13, 2021 9:41 amDo you know Where the temperature sensor the alternator use's is located?

Traditionally its integral to the alternator. Not sure if the Ranger continues to use sensor temps even if BMS is disabled.

If you're seeing consistency with the charge voltage, maybe try the BMS at different SOC% settings and see if the charge voltage tracks with the selected SOC.

Thanks guys.

No my charge voltage is all over the place. That’s why I’m convinced BMS is working even though I’ve disabled it in Forscan.

I don’t think I have the option in Forscan to change SOC% in a PX1?

The alternator only has one wire going into it on the plug, I’m wondering how this one wire signals the alternator output and whether there is some way I might be able to trick it to stay at say 14v ?

It could be plausible that the battery has reached 100% SOC. I the PX1 has any similarities then even if disabled and reaches 100% then it will shut down the alternator.

It’s possible but it’s been variable for a while, hence new alternator and battery but still same problem. Is it possible to change to ‘dual battery mode’ option in a PX1 or change SOC% with forscan?

Pretty sure you said above you had already disabled.

I have reference to it in the PX1 discussions. https://www.saeb.net/viewtopic.php?f=12&t=1213

Yes I’ve already disabled the sensor. But you guys mention a ‘dual battery’ mode in the threads and ability to set an SOC%. I can’t seem to find these options anywhere in Forscan so wondering if dual battery mode and SOC% are not options for a PX1?

You will find minimal of anything regarding PX1 vehicles as their electronic system is a totally different architecture.

Anything regarding dual Battery mode is applicable to you in the above image by selecting "without battery monitor sensor". Same same. You are not able to select a %. It's on or off, no inbetween.

hi, anyone here can tell me what other to look at that i already did? im getting battery idicaton on dash, put code reader and U1007:00-2F shown, lost communication with battery sensor A, i check the plug of the neg bat shunt it is ok, checked continuity of white wire to bcm ok and the brown/blue wire to fuse ok, alternator still charge to 14.2v sometime 13.8v.
all accessories run all negative to the body or chassi including the second battery negative lead connected to that 200mm neg lead bolted to the body.
im run out of idea other than replacing the negative lead with the sensor.
PX1 2014 Ranger.
need advise ASAP
TIA

Probably go with your gut then as you have checked the wiring. Replace the sensor and see if your diagnosis is correct.

fitter2buy wrote: ↑Sat Jan 01, 2022 4:10 pm checked continuity of white wire to bcm ok and the brown/blue wire to fuse ok,

Where is this wire in the BCM? I'd like to check my continuity from the battery sensor to the BCM but cannot identify where it enters the BCM as there are a number of white wires.

Just noticed I may not have looked this up, did you resolve the issue as yet?

Recently had similar issues and also replaced batteries and alternator without resolve.

Found earth strap to engine melted.

Made new one and voila charging 14.5v instead of 13.4v before