Alternator Recommendation?

[Dobetter]

Hey, need to replace the alternator on my '68 383 Road Runner. Year One has a factory rebuild, but wondering if you guys had any suggestions re: brands, where to buy, etc.?

Thanks in advance for your help.

[rumblefish360]

I think, IMO, YO is way to much money. SHop around. Have a local rebuild it for less?

[ehostler]

If you want to stay with original, just go get a rebuilt unit from your local auto parts shop. It won't be more than $30 with a lifetime warranty.

If you don't mind making some changes, upgrade to one of the current HD units (about 125 AMPs) found in the Ram's and Durango's.

[charger500guy]

If you want a little more flash, MAS racing products sells one for 109 bucks; they are listed in most mopar mags. I just purchased one last month, a chrome unit w/ 100 amp output. I wa very pleased with the quality of the chrome, as well as the fit, etc. Took about 1.5 weeks to come. I have put about 100 miles on it so far with no problems.....

ps they are TUFF STUFF brand

[ehostler]

If you are going to upgrade to a 100 AMP alt, you will need to modify some of the wiring (mostly, you will need to bring a haevy wire off of the alt an run it to the battery or the hot lead on the starter relay. The existing wiring and the ALT gauge in the dash, were not designed to handle that much amperage.

I myself don't like to spend money on chrome. It may look pretty, but I can think of better places to spend that money.

Also, if you buy from your local parts shop (or better yet, auto electric shop), if it fails, they are right there, when it comes time to replace after failure. Average downtime is 45 minutes. If you go with MAS, average down time is 2½ weeks

[dave571]

The cheapest, and easiest upgrade, is to get one from a slightly newer car, one of the ones with two pins.

Say for a 77 or 78 truck. The last few years of this style, are recognizable by the thin windings between the two case halves. They make up to 70 amps, and the case is a DIRECT bolt in from your old one.

What to do with the second wire?

Two options.

1)Get a regulator, from the same vinatage of vehicle, and wire it in, as the factory wiring diagram. or......

2)This is the best part. Simply run a ground wire to the second terminal, and use all your existing wiring, for the first terminal. It's that easy!

If you compare the wiring diagrams between the pre 69 and the post 70 charging circuits, you will see that the difference in the systems, are that in the earlier ones the regulator is before the alternator. It controls the positive side of the field current, while the negative side is grounded internally. ( On some of the replacement alternators for the pre 69 style it can be seen. The alternator has two posts, but one has been made so it screws on, and grounds directly to the case. )

The post 70 ones are regulated after the alternator. Constant power to one pin, while the other pin is wired to the regulator, which controls the ground of the field circuit.

I know some one is going to come on and tell me that the new ones have "two fields" and that's the difference, and that my head, is up my butt. Before anyone does so, look at the factory wiring diagrams of both circuits, and you will see I am right. I have made this modification to many cars, with no problems.

If the concern is the regulator not being electronic, on the old set ups, most of the replacements are electronic anyway(points regulators are expensive to make compared to taiwanese circuit boards), so upgrading to the new system is a waste of time.

Let the Flaming begin.

[ehostler]

The alt from a newer Ram/Dakota will also bolt right up. The only thing that it needs is a longer spacer (can be had at most hardware stores for $1.50). They also put out 125 - 165 AMPs (55 AMPS at idle).

Again though, if you are going to go over 45 AMPS, will will need to run a heavy wire from the batt side of the alt to the battery or the hot lead on the starter relay. The AMP guage in the dash will burn up if you push much more than 45 AMPs across it (would only happen if your bad is weak.

Yes, all that you need to do is tie one field lead to ground and it will work with the current charging system.

[fat bastard]

What years for the Durangos?

[ehostler]

All years for the Durango's and 94 & up for the Ram's. Try to find one with the HD service group, as they had the high output alternators. If it has a factory towing package, it should have the HD service group. Even the regular alternators put out alot more juice, than the originals. You can normally pickup a regular alt for about $70 on ebay.

[charger500guy]

What about this: I hooked up an aftermarked amperage guage in parallel to my factory guage. I would imagine that an aftermarket performance guage would be designed for more modern applications and provide for the possibility of higher output alternators, plus with two in parallel, the load on each would be shared. Soooo, do you think I still need to run an additional wire from the alt to the batt? Thanks for the help!!!

[ehostler]

Yes, you should upgrade the wiring on your charging circuit. Look at the small diameter of that wire and the contact area of the connector on the firewall. A low battery or a high current draw component is going to cause the alt to put out a high charge. When that happens, either the wire is going to melt, or the firewall connector is going to melt. Either one of these has the potential of starting a fire.