Full Size Jeep Network

Stuka wrote: ↑Sat Apr 03, 2021 6:38 pm Welcome to the forum.

First off, do you have a multimeter? Just replacing every part under the hood is kind of a brute force way of going about things. A basic multimeter that can measure voltage will save a lot of work.

If you do, start by measuring voltage coming out of the alternator, and out of the voltage regulator. And then just work down the line.

One thing I HIGHLY suggest you do, it bypass that ammeter in the dash. In your year I believe its just a dummy light, but I think all of the vehicles current is still routed through it. And is the number one cause of dash fires.

itselliott wrote: ↑Sun Apr 04, 2021 8:10 am I haven't done this in a LOOONG time...that said, there is something about the alternator needing to receive "exciter" voltage in order to turn it"on".
Perhaps doing a Google Search on that topic would help you out. Possible also, is that you need a diode in the excite wire.
Here is some good info.
https://oljeep.com/gw/alt/edge_Alternator_Theory.html

69 Gladiator wrote: ↑Mon Apr 05, 2021 3:47 pm Have the service manual. The links provided have been helpful, thanks again. Now, all I need is time; the damn job is getting in the way of the Jeep project. Again.

tgreese wrote: ↑Mon Apr 05, 2021 5:38 am If the original alternator did not have a diode, the AMP light serves that purpose. An incandescent bulb has enough resistance to prevent backfeed to the ignition switch. Also, generally a missing exciter current won't prevent the alternator from self-generating; instead, the residual magnetism in the rotor iron will be enough to start if you spin the rotor fast enough. The exciter wire will start self-generation even at idle.

Do you have a FSM that covers this year? BJ's has them https://www.bjsoffroad.com/1965-1971-Je ... _1055.html and other places should too. If you can find any Jeep FSM that covers this year, it will have the diagnostic flow chart or description for the Motorola alternator and regulator that Jeep used. As I recall, the wiring is simple - the alternator has three connections: ground, field, regulator and battery. The field wire goes back to the regulator and goes up and down in response to the battery voltage (which changes with the current required by the load). There should be the field connection and ignition (ALT light) connection to the regulator, as well as battery voltage (regulator sense wire) and ground.

You really need the FSM if you are going to do your own work on your Jeep.

Look here - https://oljeep.com/edge_74_tsm.html - Jeep was still using the (not so great) Motorola alternator and regulator in 1974, and the description and diagnostics (for the charging system only) should be the same.

Another possibility is to convert to the later Delco systems integrated alternator (10SI plus later variants) that consolidate the regulator and alternator in the same unit. http://madelectrical.com/electricaltech/delcoremy.shtml Jeep went to the modern and reliable 10SI for the sixes in 1975, and for the V8s in 1978.