I have a 2007 e350. I installed a battery isolator and I believe I need to run a wire from the ignition circuit to the exciter post on the isolator. I found the Power Distribution Panel under the hood (drivers side) which has a fuse in slot #7 (60 amp Maxi Fuse) listed as Ignition Switch/Accessory Delay. Any ideas the best way to tap into this?

Also, I have 8 gauge wire which I ran from the isolator to the batteries. I am second guessing this now and wondering if I should go with thicker wire?

 

I don't think that fuse will do you any good. According to this it's hot all the time.



You may be able to come off the trailer tow charge relay somehow. It goes on and off with the ignition switch, and is supposed to be located in the battery junction box according to this diagram. The "battery junction box" is the underhood fuse box. The "central junction box" is the underdash fuse box.



If you want to do some more research, you can find these diagrams on Autozone's site. Just plug in your van, and then go to "repair help". If you need more detail on the trailer charge relay, the diagram says it's located in diagrams 11-1, 151-1, 151-3 and 151-5. 11-1 may be another distribution diagram, 151 sounds like a trailer tow diagrams. The numbers are Fords designation for the diagram, but Autozone uses descriptions, but the numbers are sometimes on the diagrams when they come up.

 

Awesome, thanks!
Any recommendations on wire gauge or am I good with the 8 gauge?

 

I thought the trigger circuit for the isolator was just that, a small trigger circuit? Am I correct? If so, something like 16 guage would work. Of course your large charge wires would be 8 or 6, depending on the capacity of your alternator. You should know that, since that would have determined how large the isolator would have to be.

 

I ran 4 gauge for the isolator and 14 for the trigger wire which I ran through to the fuse box where I use an add-a-circuit adapter. Everything is working good on that end but now I have a new issue, maybe you can help?

The fuse I tapped into is #14, 5 amp which is labeled as "instrument cluster".
I thought this would be ok as it is only activated when keyed on.

I also replaced a couple of the instrument cluster light bulbs as the fuel gauge and oil pressure background & needle were completely dark.

It may be coincidental but now only the red colored needles are lit up on all the dials but non of the backgroud lights for the dials.
I saw that there is a fuse #36, 5 amp for instrument illumination. It seems ok given that the needles are lit.

How could just the background lights all be out?



The headlight switch works fine but rotating the **** does nothing. I thought maybe there was something wrong with the dimmer???


Does the dimmer **** dim all the interior lights or just the instrument backgrounds, nothing else in the van was dimming when I rotated it.

Thanks.




************UPDATE...


I'm an idiot!


I went back to check the fuse that I "assumed" was ok and wouldn't you believe it there was no fuse in there. I took it out to test in the add-a-circuit line to the isolator and forgot to put it back.

 

Gee, gosh. I'm certainly glad I've never done anything like that before. Honest I haven't. That's my story and I'm sticking to it.