Thread: 51 MG restoration.

Here is the booster. This one is reasonable. Lots more on Ebay
https://www.ebay.com/itm/New-Brake-B...IAAOSw7NNT4aRX

Mine....



On the alternator...One big wire on the back like this is a 'single wire'.
If two additional are plugged-in from the side, it is a stocker.
Difference is the internal regulator.



I got a kick out of that timing knob on your distributor.
Since I have a MSD box, all the advance is done by the box. The advance in the distributor is locked-down and is a magnetic pickup from the 70's.
I took advantage of the old vacuum advance and came-up with my own version of the knob.
It's spring-loaded inside and allows me to time it on a whim by turning the knurled knob....

Mine has the additional wiring harness that runs to some weird plastic fuse type thing on the frame. Not a fuse, seems a diode or something in there..?


Car sits around 12.6-12.9 vdc output and alternator gage shows right around mid point, bounces slightly between charge and discharge. Battery gage shows 12 vdc, but red charging light stays flickering even at 3000rpm.
Starts up everytime and seems to have a strong charge. Wonder if there is a way to increase output voltage slightly? Bigger pulley possibly or an adjustment..
Would like to not have blinking red lights all the time. Idle sure that’s cool, but not at speed.

That is a stock GM 7127 alternator. Big battery wire, one from there to one terminal and the other wire to the other terminal comes from through the dash bulb, through a diode, and to the terminal to excite the alternator. Without the diode, the voltage feeds back and will actually keep the car running as you turn it off.
A better plan is a 1-wire alternator, tape-up the other wire. Ammeter/voltmeter will still work.
Gen lite won't. Either way, sounds like your crusty alternator is on the fritz.

Model 7127 should put out 55 amps at least. More than enough for that car. Voltage should top out at over 14 volts, no load.

Tons of those on ebay too. They have the side terminals, yet you don't use them.
https://www.ebay.com/itm/100-New-Alt...UAAOSwmZFZpYyt
lots have a black plug over the terminals.
My parts house keeps them in-stock..55.00.
You will find them on forklifts, tractors, most anything.

You rev the engine a bit and they start working.

You will have to swap out your pulley.

Looks like a big belt!

Back in 'The Day' my 56 Chevy had the old generator and it was a pain in the arse! Green Giant was converting all of their tractors, combines etc to 12v and were using a Delco one wire alternator in place of the old generators so my father 'acquired' on for my car. I bought the mounting bracket from Chevrolet for a '71 pickup running a small block and then dad machined spacers to align the belt inline with the other pulleys.

Worked Great!!

I can't find the edition but years ago in Auto Restorer they ran an article about a company that was making 6v alternators. They even came with the wide belt pulleys.

They use the same units for 6V, Roy.
It's all in the internal regulator!

What is the big red and black thing strapped to the strut above the alternator, Mike?

Unscrewed the top thinking it was a fuse holder but it has the diode in it I think.
Not really sure what it is, but it is fed from the alternator extra connector. Decided against messing with it. But if I can go single wire off the alternator it may become redundant with the glow light. Going to my local Napa guy tomorrow, see what he has in the way of alternators. Sure chrome would be nice, but if he has a cast painted one in stock I may just grab it.
Looks like I need a new headlight as well. Car has H4s and the right one is only half brightness in both low and hi beam I noticed tonight.
Calling for rain tomorrow sadly so I may have to put her to bed for the weekend.

Originally Posted by MikeB52

Looks like I need a new headlight as well. Car has H4s and the right one is only half brightness in both low and hi beam I noticed tonight.

Mike, you might consider breaking out the Mulit-Meter and check to see if both sides are getting the same amount of juice. Sounds more like that's the problem instead of a bulb since it's happening on both High and Low Beams.

Originally Posted by MikeB52

Unscrewed the top thinking it was a fuse holder but it has the diode in it I think.
Not really sure what it is, but it is fed from the alternator extra connector. Decided against messing with it. But if I can go single wire off the alternator it may become redundant with the glow light. Going to my local Napa guy tomorrow, see what he has in the way of alternators. Sure chrome would be nice, but if he has a cast painted one in stock I may just grab it.
Looks like I need a new headlight as well. Car has H4s and the right one is only half brightness in both low and hi beam I noticed tonight.
Calling for rain tomorrow sadly so I may have to put her to bed for the weekend.

Humm....Actually, it is a feed TO the internal voltage regulator to start the unit working.
I recall it a 70's resto? Some archaic diode, I assume.
I commonly hide them in the harness.
Smaller stuff these days.
Ya. Lets be rid of that one.

Headlamp grounds may be an issue.
H4's pull way more than the original circuits can handle.
Relays off battery are the way to go., I think.
Fixed mine!

So many things can be topped with relays and stronger circuits. Using the old electrics to trigger new ones.
Esp Lights!

Check some local parts-houses, Mike!
Betcha they will have an old, universal 1 wire?