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Electrical woes

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Any one have any ideas on how the 78 MGB charging system works. I have replaced both the battery and altenator in my sons 78. I am only getting 12 volts across the altenator, I am under the impression I should be getting 13.5. My 74 gets 13.5 Does the 78 have a different system, The car was wired by the previous owner. Old wires and new wires are still in the car>could he have missed something???Next stop is the shop unless anyone has any ideas on what I have missed. By the way should the 78 not have an earth ground? I cann't find it on this car. /ubbthreads/images/graemlins/cowboy.gif
 
The alternator should have some sort of ground to the block and then to the frame. Make shure that you are getting 12 volts ignition switched voltage at the exciter spade. If that is not present then the alternator will not charge.
 
I believe the main earth or ground is found on the tranmission. At least mine is. It goes near one of the mounts to the subframe. Take a look.
WLJ /ubbthreads/images/graemlins/smirk.gif
 
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