Vannin' Home Forums Dodge How To (Dodge) Denso Alt Question:

Got 2 Denso alts at JY sale over the weekend. This 90 which I believe is internally regulated:

And this 120 amp - this one internal regulated or not? I was thinking it is not and I would use current electronic reg in my '74 - what is that black box shaped component at the bottom of the alt? Thanks, I would maybe use this 120 I guess (from a late 80's Dakota).

120 amp:

Not sure on a Dodge, no you can't use your regulator on an internal regulator alt, all the late models are internally regulated, you can toss your regulator and wire this in, I put a GM SI on my 72 Jeep in place of the Motorcraft/Autolite factory one.

I have a Denso 200a on mine. Works fine with the stock regulator, but you do need to do some wiring upgrades.

Boot, I was under the impression he was looking at internal regulated alternators, you don't need another regulator, one of my favorite things is to put a large gauge (4 gauge) wire from the alt post to the battery.

Pretty sure the 90A has internal regulator and this` 120A uses external - looks just like the '89 Dakota Denso 120 on the Autozone site. Might be that the 89 Dakota alt voltage was controlled by the ECM, so no internal regulator. I think I can use my current external w/ the 120 or delete it w/ the 90. Thanks.

Mark, I agree on the wire from alt to battery, especially on a Dodge. Electricity will follow the path of least resistance, and on the Dodges, it runs through the amp gauge on it's way to the battery, so the added wire is crucial. A good 4 gauge ground from the engine to frame is a must also, since Dodge didn't feel the need to ground the engines at all.

Will do. Would you use a fusible link on this 4ga to the relay stud or maybe a slow burn fuse or circuit breaker of some type? If so, what capacity might be good? Thanks.

Adding a 4 awg cable is only half the charging circuit path. The battery to engine ground should be 4 awg too.

I left my original 6 awg wire from alternator(+) to engine battery. It has a 4 inch length 14 awg fusible link, which, IMO, is too small and short, but never blew. It did really heat up though when the batteries were low.

I added 11 feet of 2 4awg cables(old jumper cables) from ALT (+) to my battery switch with a 140 amp circuit breaker by the battery switch, but I am thinking of adding a 8 awg fusible link at the alternator too to protect both ends of the wire.

This nearly doubled what my alternator was able to deliver at higher rpm and while cold/cool, but did not really help too much once everything was warm/hot, perhaps 20%. And the alternator heats up really fast when producing 2/3 of it's rating.

Regardless, once the maximum voltage allowed by the regulator is met, the alternator is throttled way back and produces enough amperage only to hold 14.4 volts, or whatever the regulator is set at. This can mean a 140 amp alternator is adding only 14 amps into a depleted battery. It really depends on the health and state of charge of the battery(s).

I have a digital ammeter/battery monitor so I get to see what my alternator actually produces, and it is depressing.

Ignorance was bliss.

Thanks for good info.
I am wondering if there is any advantage to installing the 120A over the 90A - I have both.

wrcsixeight - I have read a lot of your posts on electrical + other subjects. Always informative. I think we share appreciation for Bialetti Mokka Express eight cup. I use mine once or twice a day!