Opinion on electrical system upgrade

[AFCMSGT]

My current coonfiguration is 24V, with a Delco 24V alternator replacing the orginal generator/regulator. Questions: While I'm somewhat of a purist (... for originality), I'm also practical, in so much as I like to run errands around town in my '52 M-38. I would kinda like to go back to a more original set, maybe replacing only the original voltage regulator with a later (A1) solid state one, as I hear they're more reliable. Would I then need to change out my BATT CHG indicator as well? OR...should I stick with the Alternator and concede the changeout as a 'mordern' modification in the interest of reliability and functionality? What say you folks??

[skyjeep50]

I don't have any experience with the solid state regulator but reading other posts about solid state vs. the mechanical type (as in my M38A1 and M38), people say that when the solid state regulator has a problem - its a throw-away (a $200+ throw-away!), when, and if, the mechanical regulator has a problem - it can be adjusted and parts are available to repair it. If you go to the solid state reg you with have to install a volt meter, if you keep the mechanical reg you can use either the charge indicator or go to a volt meter. With the volt meter you disconnect the number 8 and 9 leads that go to the old charge indicator, terminate them, and connect the volt meter to a 27 lead from the spider harness on the back of the instrument panel. You may need to go to a 5-wire spider harness but they are available in both Parker and Douglas connector versions. The volt meter gives a little better indication of battery and charging system condition.

[wesk]

Hello Chief,

If you have a civvy 24 volt Delco alternator I would suspect it has an internal voltage regulator. You will not be able to beat the reliability of that alternator with any of the 24 V 25 A system components. If you still elect to return to stock using a 24 V 25 A DC generator and external regulator setup the old mechanical regulator when properly overhauled and maintained will last 20 years. We have the TM's here on the web site to service the stock Delco Remy and Auto-Lite DC 24V 25A components.

The transistor voltage regulator introduced in the 60's was made by Vap-Air in Chicago. We have no published data, TM's or parts lists for this regulator. It is no more reliable than an equivalent condition mechanical regulator. They have always been a throw away unit when they die. But we have a group member who is also a professional electrical engineer type who has posted in the past that he has rebuilt his transistor units using off the shelf modern components. He did offer to help supply the data when he had some time. I haven't hear from him in many months though.

If you want an original appearance and the reliability of a one wire alternator, you can't beat the GI 60 amp 24V alternator. I put one in my Dodge M37 this spring and WOW what a performer. These have a low come in speed which is essential for the slow turning engines we have. These will charge about max even at idle. The civvy units must be modified internally to charge well at 2000 RPM and below.

The volt meter is the system status indicator of choice when using a alternator. It gives the best info. The reason it is needed when you install the 24V 25A transistor regulator is because the new regulator has no internal Amp Meter shunt like the old mechanical units. Hence wires #8 & #9 have nothing to connect to at the regulator. This is why they are dead ended and you then use any power source for the volt meter that is switched off when the jeep is not in use. The #27 harness is just the most convenient nearby power source that is off when the master switch is off.

During the 80's I had a M38A1 and it was a daily driver 25 miles each way to/from work in South Dakota. I converted it to an alternator for good charging reliability in the winter.

[AFCMSGT]

As always, great advice and knowledge from the folks on this site!