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MG MGB Technical - Alternator amp question

Hello All,
I see some alternators available that have higher amperage output than stock units.

On a non-modified MGB, does the stock unit have sufficient amp output?

If you go to the higher output units, do you have to make other modifications in the electrical system?

Thanks in advance,
Dave
David Steverson

David, On a stock car the original alternator, if it is putting out it's proper output, should be fine. However, if your adding high draw lights, audio amplifiers and the like an upgrade to a GM or Bosche unit is common. If you do indeed upgrade you should also increase the wire size that runs from the alternator to the connection on the starter solonoid that goes to the battery. Ray
RAY

Depends on the model year and which alternator you install if you would need to make any changes to the wiring. The modifications are usually minor. Unless you are changing to an alternator from a generator, there are no changes in the mounting. Depending on the pulley, you may have to use a different size belt.

The amp output of the original may not be sufficient if you are using higher wattage headlights, higher draw sound system, etc.

The real difference is noticed while listening to your modern stereo while the windshield wipers, defroster, the turn signal is blinking, and the headlights are on when waiting at a stoplight.
Kimberly

David-
The output of the different alternators that equipped the MGB ranged from 34 amps for the Lucas 16AC and the three versions of the Lucas 16ACR, to 38 amps for the two models of the Lucas model 17ACR, to 43 amps for the Lucas model 18ACR. The 18ACR is usually sufficient if you keep you battery in good shape and don't load the system down with accessories that draw a lot of current.
Steve S.

Thank you all for the help. Given all this, I think I'll stck with the stock alternator for now, I don't even have a radio so I should be grand.
David Steverson

This thread was discussed between 17/01/2008 and 18/01/2008

MG MGB Technical index

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