farmall H electrical problems

i i have a '51 farmall h that has pulled some tricks out of a bag for me. I replaced every piece of wiring on it. new regulator, gen and starter reworked, new coil, new condensor, new points, the whole 9 yards. i am running an 8 volt batt on a 6 volt system, but have a resistor, and it burns the points up in a heartbeat. Im getting 7.4 volts at the distributor. and the points are gapped to .020.

At this point im willing to try anything,
thanks,
Terrell

Put a amp meter on the system (if it has an amp meter working in the switch box, use it) Turn on the ignition and watch the amp gauge with it stopped. It should show 2 to 3.5 amps draw. If it is more like 6 or 7 amps, I would use a good hand held amp meter (Multi-Meter set to amps, not Milliamps) as follows. Take off the wire on the side of the distributor. Put one ;ead om the distributor post, and one on the wire end you removed. Turn on the ignition (not started) It should read about 3.5 amps or less. More means the coil is not right. (a super hot coil might do this, or a bad coil (even new)). If it is in spec, I suspect oil or grease getting on the points. JimN

That 7.4 volts you claim is at the distributor puzzles me??????

With the points closed there should be near ZERO volts at the distributor and with them open it should be near full battery voltage which is like 8.4 volts!!!!!!!!!!

You say you have a resistor buttttttttt if its a 6 volt coil on an 8 volt system that ballast resistor (if sized correct) would be quite a bit less resistance then a regular ballast for a 6 volt coil on a 12 volt tractor..

All that aside possible causes or premature points burn up are: 1) Excess current (points and coil), it shouldnt be much over 4 amps if even that high, but if a lot more the points will burn quicker 2) A BAD OR INCORRECT SIZED OR NOT GROUNDED OR MISWIRED OR POORLY GROUNDED CONDENSOR 3) Residue on points 4) Maybe a bad distributor shaft bushing/bearign and the gap is drifting all around

With a 6 volt coil and some sort of ballast on an 8 volt system I dont see excess crrent as the first problem so Id really be checking the condensor and of its wired correct and if its well grounded to the distributor as the cause of premature points burning

Since youre willing to try anythign Id start with a new condensor and insure its ground. Im curious about those voltage readings also. If theres 7.4 volts at the INPUT of the 6 volt coil (NOT the to distributor terminal) when the points are closed n conducting current that may creat a bit of excess current but not enough to quickly fry the points

John T

Something popped into my mind reading your input! what if he wired the "ballast" resistor across the coil (parallel) instead of in series with its input!

Tgrewing, how is that resistor wired , and how much resistance does it have? JimN

HMMMMMMMMM interesting thought, Ive no doubt that could easily be done and I see how it could increase points current and shorten their life huh. With say a 1.5 ohms ballast in paralell with a 1.5 ohm coil the net resistance is only .75 ohms which reallyyyyyyyy increases points current (8/.75 = 10.66 amps) and reduces spark energy alike

Nice catch if thats what he did and fer sure it would burn the points quickly

JT

the resistor is wired as follows:
the hot wire goes striaght into the resistor
wire from oppisite side goes to neg. side of coil
wire from pos. side of coil goes to distributor

SETUP IS POSITIVE GROUND...
Thanks,
terrell

That is correct wiring. I would change out the coil with a different 6v to see if it is the coil, or get us the amp draw. JimN

i checked the ground on the condensor....
i took some light sand paper and polished it up
it slowed the process of the points burning up but it still burns them quicker than normal

if anyone has any other solutions, please let me know,
THANKS,
terrell

Change the condenser (even put the one that came out back in) I have seen many new bad condensers. Condensers are pretty much good for many years unless physically damaged, leaking dielectric, or radically overheated. But new ones can and have been known to be way out of spec. JimN