Setting up a second battery in my 95 E150 Mark3 Conversion and looking to add a battery isolator or DC to DC charger, but I think there may already be something similar installed... Is the part in the images below a battery to battery charger of some sort??? It's installed on the wall of the engine compartment right in front of the battery and connects to both battery posts. Looks like a low gauge yellow wire and red with light blue are connected also... I think there is an empty battery harness underneath but im not sure and don't have pictures of it. What do ya'll think?

 

That is a solenoid to switch on battery voltage to the accessory circuits that may be connected to loads by a conversion company. It supplies a 12 volt circuit to the 7pin trailer towing socket. There are other branches running down the left inside quarter panel. It wont work for combining a second battery to the van. Adding another solenoid is needed if you want 2 batteries in parallel while cranking and charging both while the engine is running.

 

Thanks! That makes sense. Would there be any problem installing a battery isolator along with the solenoid?

 

Nothing wrong with adding an isolator as long as you wire it up correctly. Why do you need a second battery ? What are you going to power with it ?

 

It's the house battery for a camper conversion. Will charge mainly off solar but want another charging option. House battery will power a vent fan, water pump, inverter etc.

 

The item in the photos is the Starter Motor Relay and has nothing to do with a second battery charging.
The yellow wire is going to the engine compartment fuse panel.

 

 

Yes the starter motor has a solenoid mounted on top of it but he still has the stater relay in the engine compartment. The photos he posted is photos of the stater relay and has nothing to do with the trailer wiring or Aux battery charging.





Click on image to enlarge.
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Yeah that is where my starter relay is located also.

 

Dam i assumed that entirely WRONG !! I had glanced at it a few years back and saw the large and small yellows , alternator charge wire and battery feed wire to the trailer connector on the post and assumed those loads were being energized by the solenoid. Nope, Ford uses the solenoid to supply voltage to the the solenoid on the starter motor. Did not see the small 16 gauge wire attached to the other post .

 

That one caught me by surprise years ago, after being used to the short battery positive cable to the fender mounted solenoid. From there, the long battery cable to the starter was hot only when cranking. Easy screwdriver or pushbutton shorting the battery side to the energizing screw to spin the engine.

Then they put the solenoid pictured above to power the other solenoid on the starter below. ???? Now there is a permanently hot, fairly long, non-fused large battery cable snaked down to the starter. The diagram shows the starter motor right beside the battery and the solenoid that is actually beside the battery further away. Scale means nothing when following wiring diagrams. The gear reduction starter (PMGR) is a definite plus. I'll take that and live with the always hot starter cable.

My 1994 van came with the second aux/house battery installed and a continuous duty solenoid hidden underneath the driver's side battery, accessed by removing the headlamp and using the hole behind it. Cramped. A battery cable runs across the front top of the radiator to the aux/house battery on the passenger side. In my case, the aux/house battery solenoid is energized only with the engine running, to avoid draining both batteries if the key switch is left on.

Zacto, does your van have a battery tray on the passenger side? I actually prefer a continuous duty solenoid over an isolator due to the isolator's inherent voltage drop and I'm old and like electromechanical devices.

My charging voltage measured at the starting battery ranges from 13.9 to 14.8 volts. 130amp alternator. As long as the charging voltage rises to the high 14's, the paralleled system worked well until a 12v fridge showed up and I parked without much driving. I do not have the fuses seen in the diagram in the link below, to provide starting current from the house battery if necessary.

This link from another forum has enough info to make your eyes bleed.
https://expeditionportal.com/forum/t...-for-50.77503/

 

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No battery tray on the passenger side but I think there is one on the driver side. It looks a bit small for a battery though. I'll get under her for some pics when I can.

Going with a smart isolator over a solenoid. Smart iso doesn't cut in until 13.3V and cuts out at 12.8V

 

Nice to have diagrams, I had to figure mine out myself on account it was a used unit, but it worked great!




...and what the Circuit Breaker looked like

 

Nice! Which isolator is that? And what gauge wire did you use from the isolator to your second battery?

 

Our RV van has it like this:




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