Dual Battery Exciter

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Jul 31, 2005 | 11:24 AM

gibsondan

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Dual Battery Exciter

Working on putting in a dual battery with isolator in my 2003 E350 (6.8L). Reading through Sure Power's instructions, it says that most pre-1999 Ford's must use the exciter post to an ignition-only power source. Then, I've read other people who have not had to use the exciter post in a 2001 Ford (an article in www.ford-trucks.com, no less). Two questions:
1-Do I have to use the exciter in my case, as I cannot find out if I do or not.
2-What to use for the power source if I do? I show hot power to everything from the power distribution box under the hood when the vehicle is even in the off position.

Jul 31, 2005 | 11:39 AM

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Jul 31, 2005 | 03:31 PM

Franklin2

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From: Virginia

I went here http://www.surepower.com/pdf/180012n.pdf to get up to speed on what you are doing.

It seems it depends on what type of alternator you have, and apparently later Fords have the type, where they will not start charging by themselves. They need a little kick of voltage applied to the output of the alternator to make them come "online".

You could try it without hooking it up, and see if it works reliably. If someone got it to work without the excite wire, it may be due to their particular installation, and possibly enough leakage current making the alternator kick in.

I think if you really want it to reliably charge everytime it's started, I would follow the instructions and add an excite wire. This may mean running a small wire through the firewall and into the underdash fuse box if you can't find a source in the engine compartment. You can buy a fuse tap to hook it into a circuit in the box.

Aug 1, 2005 | 05:11 AM

gibsondan

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Yes, that is the instructions I have. You are probably correct - wire the exciter regardless.

It appears everything is hot in the power distribution box under the hood, including the IGN fuse. Have a good recommendation what circuit is hot (either in the engine compartment or in the fuse box under the dash) when the ignition is on but no power when the switch is in the ACC position?

Aug 1, 2005 | 04:07 PM

gibsondan

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Ignition line is the red/w green stripe? Can I just tap that (w a fuse inline, of course)

Last edited by gibsondan; Aug 1, 2005 at 04:07 PM. Reason: addendum

Aug 1, 2005 | 04:43 PM

fordboy_52

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if i was u i would buy a good one, i put a cheap on in my truck for my stereo and it crapped out about a week later

Matt

Aug 1, 2005 | 05:21 PM

Franklin2

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From: Virginia

Quote:

Originally Posted by fordboy_52

if i was u i would buy a good one, i put a cheap on in my truck for my stereo and it crapped out about a week later

Matt

Those surepower units look very good( and expensive).

Alternators can sometimes be a little noisy(electrically speaking). I don't know about tying it to the ignition or any of the computer stuff. What about tying it to the power that runs the fuel pump? That's a pretty heavy circuit. You should have a fuel pump relay in a box under the hood.