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alternator problems

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Evansa69Midget Avatar
Evansa69Midget Al Evans
Smyrna, TN, USA   USA
I bought a 1970 mgb with a fried delco single post alternator. Now comes the problem. I bought a autozone lucas alternator with 5 connections and I'm not sure how to connect it since the wiring was for a 3 connection delco? The delco didn't fit on the car. So buying another delco was out of the question. Need Help, so I don't fry another alternator or worse, the wiring harness.

Al

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ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
A CS 130 fits easily after 15 minutes of mods
3 wire plug gm style.



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972


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8107 alternator conversion.JPG

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ingoldsb Avatar
ingoldsb Silver Member Terry Ingoldsby
Calgary, AB, Canada   CAN
1971 MG MGB
Too late tonight to respond - bug me tomorrow and I'll help you sort out the connections - it isn't hard or complicated.



Terry Ingoldsby
terry.ingoldsby@DCExperts.com

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Evansa69Midget Avatar
Evansa69Midget Al Evans
Smyrna, TN, USA   USA
Auto Zone didn't have a reference number that matched A CS 130. need help on where to get that alternator? Thank You

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ohlord Avatar
ohlord Gold Member Rob C
North of Seattle, N.W., USA   USA
1957 Land Rover Series I "EYEYIYI"
1971 MG MGB
1971 MG MGB "Bedouin 2"
All done with pulley and plug and instructions
https://123ignitionusa.com/alternators/
https://123ignitionusa.com/alternators/

Or 3342378 cs130 the correct plug and a deep groove GM v pulley and clock the unit to fit the stock mgb bracket.
You don't need a chunk of welding wire or 2ga back the the starter post. 10ga along the OEM wire does just dandy.
No fires as often claimed from someone with no knowledge of an mgb.
The procedure for swapping the pulley and clocking the alternator are in the mge tech library. thumbs up



"I'm a long way gone down this wild road I'm on
It's gonna take me where I'm bound
It's a long way around"



"These are the days that must happen to you"

RD2 Radar/ Electronic Warfare Technician
Vietnam 1969-1972

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ingoldsb Avatar
ingoldsb Silver Member Terry Ingoldsby
Calgary, AB, Canada   CAN
1971 MG MGB
So - did you still need the connections for the 5 pin Lucas?



Terry Ingoldsby
terry.ingoldsby@DCExperts.com

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ML320X5 Avatar
ML320X5 Stan Y
Tulsa, OK, USA   USA
1952 MG TD
1973 MG MGB
2002 BMW X5
Don't know if this help. Bought a lifetime warranty unit from NAPA back in 2017. P/N=213-8087 for my stock 73B. No mod whatsoever. Direct hook up and bolt on.



Edited 1 time(s). Last edit at 2019-03-15 08:20 PM by ML320X5.

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Evansa69Midget Avatar
Evansa69Midget Al Evans
Smyrna, TN, USA   USA
Stan,

I have a odd situation with this 1970 mgb. The alternator is not as much a problem (even though it was fried), as the messed up harness and what that person did with a make shift rigged wiring with a delco Remey alternator. I've been given two different approaches, both good advice, not sure what direction to take. a new GM alternator with some modifications is one way. While the other approach is use a newer 73 lucas 3 post alternator and undo the already shad tree wiring and restore it to a 3 post wiring convervion. reguardless, I got to tackle the wiring issue first. The Tech guys at moss motors said that the 3 post wiring conversion is the way to go, since there is no 5 post connectors being offered by anyone.

Any imput you have would be good. Especially on how the wiring from the starter to the alternator should go. Along with the wiring to the starter relay and the fuse box. I'm a retired science teacher with some knowledge of an Ohm meter. I took all the blue wiring harness tape off to expose any fried (burn't) wires. only the 2 hot big brown wires were fried a the starter solenoid I replaced the fried 10 guage wires from the starter solenoid to the alternator. I hoping that is all the changes in the wiring I have to do.

Al

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ingoldsb Avatar
ingoldsb Silver Member Terry Ingoldsby
Calgary, AB, Canada   CAN
1971 MG MGB
Quote: Any imput you have would be good. Especially on how the wiring from the starter to the alternator should go. Along with the wiring to the starter relay and the fuse box. I'm a retired science teacher with some knowledge of an Ohm meter.

We have no problem telling you what to hook up where - but you've got to tell us which alternator config you have decided to go with.

Most modern alternators need two wires, and occasionally a third. One is the power out. On the MGB this is the thick brown wire and will usually connect to the heaviest connector on the alternator (regardless of type). The brown/yellow wire comes from the lamp on the dash and connects to the "Field" connection on the alternator. On many alternators, that is all that is required. These alternators are called machine-sensed because they sense the voltage at their own output.

A few alternators have a third, voltage sense terminal. This allows more accurate sensing of the battery's voltage and such alternators are called voltage sensed. Some original MG alternators were voltage sensed and some were battery sensed. Even cars that had the third wire often had alternators that didn't actually use the third wire. This extra wire is a thinner brown wire that connects to the power terminal on the starter solenoid. If you have a machine sensed alternator (which will include many of the Delco substitutes) then the thin brown wire is not needed.

P.S. Why did the early Lucas 16ACR alternators have five terminals? Not entirely clear. A couple of the terminals are jumpered together in the connector. Lucas could easily have done this inside the alternator. I speculate that it had something to do with the transition from having an external voltage regulator (16AC) and the internal regulator (16ACR). A 5 pin alternator can be easily converted to a 3 pin alternator by swapping out the rectifier pack inside the alternator.



Terry Ingoldsby
terry.ingoldsby@DCExperts.com



Edited 1 time(s). Last edit at 2019-03-15 04:06 PM by ingoldsb.

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Evansa69Midget Avatar
Evansa69Midget Al Evans
Smyrna, TN, USA   USA
Terry,

I have a odd situation with this 1970 mgb. The alternator is not as much a problem (even though it was fried), as the messed up harness and what that person did with a make shift rigged wiring with a delco Remey alternator. I've been given two different approaches, both good advice, not sure what direction to take. a new GM alternator with some modifications is one way. While the other approach is use a newer 73 lucas 3 post alternator and undo the already shad tree wiring and restore it to a 3 post wiring convervion. reguardless, I got to tackle the wiring issue first. The Tech guys at moss motors said that the 3 post wiring conversion is the way to go, since there is no 5 post connectors being offered by anyone.

Any imput you have would be good. Especially on how the wiring from the starter to the alternator should go. Along with the wiring to the starter relay and the fuse box. I'm a retired science teacher with some knowledge of an Ohm meter. I took all the blue wiring harness tape off to expose any fried (burn't) wires. only the 2 hot big brown wires were fried a the starter solenoid I replaced the fried 10 guage wires from the starter solenoid to the alternator. I hoping that is all the changes in the wiring I have to do.

Al

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Steven 67GT Avatar
Steven 67GT Steven Rechter
Jackson, CA, USA   USA
In reply to # 3908979 by Evansa69Midget Auto Zone didn't have a reference number that matched A CS 130. need help on where to get that alternator? Thank You

Ask for a 1994 Saturn alternator.

edit: Autozone, etc., will transfer your pulley to the new alternator for free.



Edited 1 time(s). Last edit at 2019-03-15 04:46 PM by Steven 67GT.

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Evansa69Midget Avatar
Evansa69Midget Al Evans
Smyrna, TN, USA   USA
1994 Saturn alternator. Did saturn have multiple engines. If so, was it a 4 or 6 cylinder?

Thank You for your imput.

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Evansa69Midget Avatar
Evansa69Midget Al Evans
Smyrna, TN, USA   USA
I got an Autozone 1973 lucas 3 post alternator. It has 2 large copper post and a smaller silver post. All there are in a straight row.

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ingoldsb Avatar
ingoldsb Silver Member Terry Ingoldsby
Calgary, AB, Canada   CAN
1971 MG MGB
Quote: I have a odd situation with this 1970 mgb. The alternator is not as much a problem (even though it was fried), as the messed up harness and what that person did with a make shift rigged wiring with a delco Remey alternator. I've been given two different approaches, both good advice, not sure what direction to take. a new GM alternator with some modifications is one way. While the other approach is use a newer 73 lucas 3 post alternator and undo the already shad tree wiring and restore it to a 3 post wiring convervion. reguardless, I got to tackle the wiring issue first.

As I said earlier, we can tell you what to do, but you need to tell us which alternator you plan to use. Any one will work - but you have to decide.

As a general rule, the output of the alternator connects to the main positive terminal on the starter solenoid. If you follow British wiring conventions, use a brown wire. The thickness of the wire depends on which alternator you decide to use. The stock 16ACR (34 amp output) will need about an 8 or 10 gauge wire. If you use a higher power Delco or Bosch you will need a 6 or 8 gauge wire.

The brown/yellow wire that comes from the lamp on the dash will connect to the field terminal on the alternator. Several different connectors were used on Lucas 16ACR alternators, so you need to tell us which 3 terminal Lucas alternator you plan to use in order for us to tell you which terminal needs to be connected to the brown/yellow wire.

Some alternators have a separate voltage sense terminal. If the alternator you plan to use has voltage sense, you will need to run a thin (18 gauge is fine) brown wire from that terminal to the starter solenoid positive terminal.



Terry Ingoldsby
terry.ingoldsby@DCExperts.com

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Donthuis Avatar
Donthuis Don van Riet
Rijswijk, ZH, Netherlands   NLD
One point of consideration is how much power you really need. Although these Lucas alternators, even in its latest 18ACR version generate only moderate power, in fact one hardly needs high amperage with a normally equiped B. Of course if one mounts a HIFI set with hunderds of Watts dissipation choices will be different, but those configurations I do not associate with owners of the MGB, modding fanatics maybe excluded. IMO even the old 16ACR supplies enough for keeping your battery happy and feeding the lights. After replacing most in not all bulbs in the lights by LED's will get you hardly any load left on the alternator. On my B there was once a 5 terminal 16ACR, which was replaced by a second hand 3 terminal 16ACR (just cutting the extra wires away!) and by now I have a 17ACR in.

With all but the headlights now in LED, head lamps excluded, I have no need for a more powerfull one, be it CS130 or Delco. Proper LED headlight replacements are just becoming better and better, so maybe next year even that load will largely disappear. Two headlight bulbs draw 10-12 Amps, LED's will probably reduce this to only 4-5 Amps, together with the ignition and other LED's 10Amps in all?

The advantage of the 3 terminal Lucas or aftermarket 17ACR/18ACR types is -if the provider is selected with care- that most come with the right pully and fanblade already mounted.
The 3 terminal connector is nice to have, but for many years I just had two spades connecting the thick brown feed wire to the larger spade and the yellowbrown ignition bulb wire to the smaller spade thumbs up



Edited 1 time(s). Last edit at 2019-03-17 06:04 AM by Donthuis.

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