Alternator

[Germy]

I have a very loose post on my alternator. I am going to replace. My confusion is when I installed the painless harness, the diagram was calling my ignition ford motor craft. I have one post and one plug, can someone school me real quick? I am also wondering, when I order motor parts for my 85 CJ7 w/360, I look up 80 CJ7 w/AMC 304 , these are the same blocks right? Thanks!!!!!

 

[Purple77CJ7]

I can't help you on the harness, but a AMC 304 ,360,401 all use the same external components and some internal. The block dimensions are the same, different bores and use different cranks and different balancers.

 

[81laredo]

Yes, my '81 CJ7 had the Motorcraft Ignition System. You will also find that your Starter is FORD as well!
My Alternator was not the Single Wire though and it sounds like yours isn't either.
You may need to contact Painless but I would expect that the Alternator Output will still go to the Starter Solenoid as originally connected.
Sorry, I cannot help you with the Ignition since I eliminated all of that Motorcraft junk and went with the HEI Distributor. The new Distributor made allot of welcome difference in power etc.

 

[Germy]

I have hei too. Just wondering what alternator to buy? Do I buy one for a jeep or is my alternator ford?

 

[81laredo]

My CJ7 is a California version so I will be staying the the OEM Style because of the Serpentine Belt. Personally I like the GM Single Wire type because of availability and you could choose higher output but this is your choice because there may be wiring changes.

 

[Germy]

Cool cool. Got it figured out!!!! One remaining question! Why are there two separate belts going from crank to alternator? Redundancy? Is my cj an airplane??!! Can I get by with one belt?

 

[Purple77CJ7]

My 401 only has one belt. Two are better for high amp loads so belt doesn't slip and squeal.

 

[Germy]

Po had a HUGE stereo. 4 amps. Maybe that's why! I wish he would have spent the money on a new lift! I'm going to one belt. Thanks everyone!!!

 

[Germy]

Replaced alternator and lights still dim. They dim at idle kinda with the rotation of the engine. The voltage meter is reading 11. Battery?

 

[73CJ]

Sounds like it. Battery. At 1500rpm you should have 14- 14.6 volts.

 

[Germy]

Thanks! Battery tomorrow, any suggestions on brand?

 

[73CJ]

I like the yellow top gel cell.

 

[Germy]

Do you need a special charger for that?

 

[dunebuggy18]

Check your ground connections! If you do not have a solid ground for the alternator (case to chassis) you will have a voltage drop (and dimming lights at a stop sign). Check that you have a solid ground strap from the engine to the frame in place, and good battery connections. Do you have a one-wire alternator system? If so, that could be your problem as well. The internal regulator only sees voltage at the alternator output, so voltage drops "down stream" of the fuse block it won't sense, or regulate the voltage for.

Hope that helps!

 

[dunebuggy18]

The link below has a lot of great information about alternator circuits:​

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http://www.madelectrical.com/electricaltech/delcoremy.shtml​

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[Germy]

Ran a ground strap from block to firewall, no change. Charged battery all night, still reading 11 amps at gauge. Think it's battery time?

 

[dunebuggy18]

Do you have access to a volt meter? If your battery is reading below 12 volts, yep - it's battery time (should read 13+ volts with no load). If you don't have a volt meter, take the battery to Sears and they will check it for free. Most part store will as well.

I agree with the post above - The Optima red top or yellow top is the best choice for a Jeep, but they are pricey...

 

[Germy]

Bad battery! They gave me a return for 30 bucks! The battery is priced at 90 bucks. I'm happy!