View Full Version : Another alternator question...

05-24-2005, 07:18 PM
Alright, I have convinced myself that dumping my Lucas alternator for a more powerful one is the thing to do. Now, having read and re-read Dan Master's bible on TR6 electrics, I think I want to go with the Bosch unit that puts out 55 amps. This is the one and same that Ford had in their 78-80 Fiesta. The problem is Bumper-to-Bumper has several listings for this application. Do I want an alternator with or without voltage regulator? The only voltage regulator that I am aware of on my TR6 is the little unit attached to the back of my speedometer, and that is just there to drop the voltage to some of the gages, I think. There is no voltage regulator on the firewall of my car, and what the heck would I need one for anyway. The Bosch alternator on the Fiesta is supposedly a direct plugin. Right. Like that will happen. Anyway, comments???


Andrew Mace
05-24-2005, 08:08 PM
You probably want an alternator WITH the internal voltage regulator. TR250s and possibly early TR6s (not really sure about that) used an alternator with a separate regulator, but yours undoubtedly is the type (i.e., Lucas 16ACR) with the regulator built in.

05-24-2005, 11:20 PM
The thingy on the back of the speedo is a voltage stabilizer not a regulator. The Bosch is a direct fit, although you might have to buy the Moss plug adapter (540-280) if your car is below 1973, or make your own.

The only other mod I did, was to run 8 gauge wire from a spare positive terminal on the new alternator to the positive battery connection on the starter. This is to prevent my stock wiring from melting if my battery is totally discharged and the alternator tries to charge at full capacity. The OEM wiring was not designed to handle 55-60 watts.

I got my alternator from this guy:
https://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=7950500125&category=33 573

I could have gotten it a little cheaper, but I didn't want to give my old lucas up as a core and all the local parts stores had to special order it, so it was mostly a wash.

05-25-2005, 10:01 AM
As stated above, get an alternator with an internal regulator. Whether you use a Lucas style plug isn't really important. There are typically only three wires to deal with and these are easily sorted out.

I assume the extra connection Shannon is mentioning above was not in fact to the starter itself, but to the hot side of the starter solenoid. You don't want power going directly to the starter all the time.

I have also bought from the seller in Shannon's link above. They were absolutely great on the phone when I discussed my application with them.

05-25-2005, 08:53 PM
I called the guys at the above link and the fella that sorta tended to these particular cars' alternator needs had "left the company". Unfortunately, they weren't much help today. Perhaps I will call back in a few days and see who may have taken over his task. Still looking. I know this sounds a little bling-bling, but I would really like to get a chromed Bosch. Alright, stop laughing.