Topic: Electrical How-to

[chrisfranklin]

Also doing an upgrading electrical system how-to might be a useful: ie., what do yo need to do to run multiple high-powered electrical devices successfully on your 4 cyl wrangler/cj;  for example, say a  winch, radio/six speakers/satellite unit and amp, laptop/cell/cooler/CB/Ham/GPS/inverter, high powered off-road lights/headlights, electric fan for cooling, aftermarket air horn.  

What do yo suggest: 2 optima batteries in series, upgraded high-powered alternator, some kind of change with the fuse box/wiring?  I have had problems with electrical in the past and, not being an electrical engineer and having only a vague understanding of circuits, I am not sure what would be involved with upgrading your 4s electrical system to handle numerous electronic devices simultaneously. :?

[yellowta]

A high powered alt. would be a good idea to push all of that at once, especially the high drain devices like the amp and winch. Really the only thing you have to worry about is power and ground. As long as all of your devices have a large enough guage power wire they should not have problems with overheating. When it comes to the amp, high powered lights, fan, and inverter you should go direct to the battery. I'd recomend running a large guage wire (at least a 4 guage) from the battery to an aftermarket power distribution block on the inside of the firewall to run all of your interior stuff.  Do the same with a large guage wire for a ground that goes straight to the battery. If things are not properly grounded, wierd things start happening :?   As long as you keep the factory fuse panel free of other major current draw, your devices will not effect your stock equipment. That way if something doesn't work, it will be easier to troubleshoot :wink:

[Jeffy]

Well, first off, you have to consder how many of those things you'll have on at once.  If you're winching, I doubt you'll have your stereo blasting.  Horn?  How often do you use your horn?

A larger battery would be ny first choice.  The stock is 475-500cc and it's small.  Something like an Optima, Black Panther or Odyssey would be optimal.  You could go with a Duralast, Napa/Optima, Interstate/Optima, etc...

I agree that a remote power block mounting inside would make wiring much easier.  Then you don't have to run a bunch of wires thought the firewall.

This subject is a bit too broad for a how to.  Basically you're asking, "How do I rewire my whole Jeep."  There is no set answer because different needs require sifferent solutions.  Not everyone will need to run dual batteries and a high amp alternator.  Would it hurt?  No but would they really need it?  It would be like using Dana 60's when all you want to do it run 31's.  So ask your specific questions and they'll be answered.

[black99tj]

Those batteries need to be connected in parallel. NOT SERIES. Series will double your voltage to 24 volts. Parallel keeps your standard 12 volts and just increases amperage.

[Islander]

Who makes a good high output alt?

[chrisfranklin]

If I recall correctly, a while back, I was seeing the fuse to my stock alternator blow quite a bit.  I had a lot of electronics drawing on it simultaneuously which may have overloaded it or something to that effect.  This was on a cross country drive.

Already run an Optima, so maybe an alternator upgrade would be advisable.   Not intending to run a winch.  Really more ordinary stuff like amped stereo and secondary, multiple 12V work-related electronics, in addition to  navigation, & maybe an electric fan for the cooling system.

All this draws on the battery.  The battery, in turn, is charged by the alternator.  When a fuse connecting the alternator to the fuse box, which in turn is connected to the battery, blows, what causes it?
Is it a matter of the battery being overtaxed and attempting to overdraw from the alternator?

[yellowta]

Mean Grean is supposed to be good, but it would be much cheaper to find an alt in a junk yard, or have your's rewound at an alternator repair place.  This is a good write up on finding high amp OEM alternators that should bolt right into your jeep:  http://www.bc4x4.com/tech/2004/jeepalt/

[chrisfranklin]

yeah good link, yellowta :D

[Islander]

Mean Grean is supposed to be good, but it would be much cheaper to find an alt in a junk yard, or have your's rewound at an alternator repair place.  This is a good write up on finding high amp OEM alternators that should bolt right into your jeep:  http://www.bc4x4.com/tech/2004/jeepalt/

Wow, nearly $400 for an alternator... and that write up "has only been confirmed on 4.0L's" - granted, it should still work for us - but I'd have a good electrical grade fire bottle at the ready when I wire that little project up.  It also doesn't cover pre-91 YJ's.  Good write up if all you're P/N's match up though.

[Jeffy]

2.5L and 4.0L MPFI's use the same alternators.  Although, since you have a pre-91, it uses a different alternator and the brackets are very different also.

I think the MPFI's use a Nippondenso.  I forget what pre-91's use but you should be able to read the ID tag and see.