TR5/TR250 TR250 - Alternator Upgrade - Questions

[angelfj1]

I am still running with the original Lucas 15AC alternator since 1983. I have had to replace bearings once and the bridge rectifier 3 times. Yesterday I experienced the 4th diode bridge failure. I think the replacement diodes are inferior and are failing due to inadequate heat transfer to the heat sink. Anyway I am considering one of the many alternator upgrade options. The 250 (and I think 69 TR6) have a unique setup in that it has an external regulator. The later model TR's had internal alt. regulators.

Are there any TR250 or '69 TR6 owners out there who have upgraded and which unit did you use?

How do you deal with the external regularor?

Thanks

Frank

 

[TR3driver]

Early Stags (like mine) also used an externally regulated alternator. Pretty much everyone that upgrades, goes to an internally regulated unit. The wiring gets changed around a bit, to effectively bypass the external regulator.

Looking at the TR250 wiring diagram, the wiring looks easy to me. Just tie off the NG wire at the alternator, and connect the NY and NW wires to the appropriate tabs. Some alternators will also have a 'sense' input, for which you can either run a new wire up to the starter solenoid, or just jumper over to the NW wire.

The jumper to the NW wire will reduce the alternator's output slightly, but lots of people run that way and are happy with it. Besides, with the new wire option, the ammeter will hit the peg after every start.

Another option might be to construct an upgraded rectifier assembly. Those skinny steel tabs can't be very effective, I think you could machine a much better setup from aluminum, and then source some press-fit diodes to fit.

There might even be enough room in there for the diode assembly from a Delco 10Si.

 

[angelfj1]

Early Stags (like mine) also used an externally regulated alternator. Pretty much everyone that upgrades, goes to an internally regulated unit. The wiring gets changed around a bit, to effectively bypass the external regulator.

Looking at the TR250 wiring diagram, the wiring looks easy to me. Just tie off the NG wire at the alternator, and connect the NY and NW wires to the appropriate tabs. Some alternators will also have a 'sense' input, for which you can either run a new wire up to the starter solenoid, or just jumper over to the NW wire.

The jumper to the NW wire will reduce the alternator's output slightly, but lots of people run that way and are happy with it. Besides, with the new wire option, the ammeter will hit the peg after every start.

Another option might be to construct an upgraded rectifier assembly. Those skinny steel tabs can't be very effective, I think you could machine a much better setup from aluminum, and then source some press-fit diodes to fit.

There might even be enough room in there for the diode assembly from a Delco 10Si.

<span style="font-weight: bold">


Now that's a HEATSINK!!!</span>
[size:14pt][/size]

 

[TonyPanchot]

I have changed to the GM 96 amp and works like a charm
very simple your large br/y to main stud and the small br /w I think , can check if you want to the + spade on alt.
35.00 Autozone, lifetime
make sure to get the one with the full fan, not the metal and 3/8 pully.
simple

as for the external reg. it is just a fixture

 

[angelfj1]

Thanks Tony. Any details that you can provide would be appreciated, like model no, wiring, etc.

Thanks

 

[TonyPanchot]

I will take some pic's today