Delco-Remy Generator Output

I have fitted electric starting and lighting to my Farmall H. I went with Delco, because it meant everything just bolts straight on. The system is 6 volt, positive ground and fitted with a voltage regulator. The only problem I have found is that the Delco generator barely keeps up with the current used by the headlamps. The headlamps are 36W each, so they pull a current of 12 amps. With the rear lamp (24W) also switched on the total current flow is 16 amps. This brings the ammeter back to a discharge of about 1 amp with the motor running fast. The C39 generator on my Farmall M has no hassle with these lamps at all. Do I need to alter the VR setting or just leave it alone? Thanks in advance.
SadFarmall
 
I dont have the specs on your genny, Bob M or Jim might?? However, Id guess 20 amps is all it may pump on a good day AT HIGH RPM

Try to dead ground the Gennys FLD post and see what happens??? If charging dont increaSE much the VR is NOT the problem nor will adjustments help. If it does increase, (may need adjusted up) insure the VR has a good ground (try a jumper to grnd)

If its a 3 brush genny, adjusting the third brush may help....Insure belt is tight........Can you use a smaller pulley on genny????

Other things may be to check brushes for length,,,,,,insure brush hold down springys are good n tight,,,,,,,,insure commutaTOR IS CLEAN and free or oil or carbon ,,,,,,,,,if third brush adjust,,,,,,,,,INSURE VR well grounded,,,,,,,,belt,,,

Unless youre gonna run hours n hours with all lights on May just live with if the above is all good

John T Live from Florida Flywheelers
 
What is a c-39 generator? If you would have used the Delco-Remy gen 1100501 or 1100531 and the correct reg that goes with them and the original lite sw wired correct you wont have any problems.
 
A couple thoughts:

1 - The OEM 6 volt headlamp bulbs were rated at 24 watts (= about 4 amps). Your 36 watt bulbs require about 6 amps eac). So if you add the amps for the head/rear light, then another 3 or 4 amps for the ignition you are looking at a constant 20 amp load.

2 - The stock 6 volt generator is good for a maximum of 16 - 17 amps. And this is with following:
- the generator brushes/commutator in top shape
- both the fan and generator pulleys sheaves set a far open as they can go without slipping (to spin the generator as fast as possible)
- the generator 3rd brush (if equipped) set to "max output"
- the engine spinning at governed RPM
- the generator cold (maximum output drops by a couple amps as the generator warms up).

If any of the above are not met, generator output will be lower.

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My recommendations:

Check both the generator AND fan belts. If they are at all loose/stretched, replace with new. And run them with the adjustable sheaves as far OPEN as possible.

If the generator has an adjustable 3rd brush, set it as close as possible to the nearest fixed brush. (Note later production generators is not adjustable - it is permanently fixed in the maximum output position.)

You might try swapping the VR with the one from your M and see if it holds the load better than the one on it now.

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Incidentally my experience growing up running H's and M's at night is they will constantly discharge several amps except running wide open. However with a good battery they would run like this all night and still have enough reserve to crank up the engine the next day.
 
They are just at the margin of successful and after 50 years or more they are on the other side of the margin. Were it mine I would put LED bulbs in all three lamps. (available but not very cheap) they will fit the socket, and use 1/3 the amps, while giving far more light. The tractor would be undetectably modernized with no other issues. (be sure to use 6v LED replacement lamps. Jim
 
Yo Bob, Ive seen some Delco data (prob more for JD) where the third brush was to be set NO CLOSER then 1.5 commutator segments (from fixed brush) and others 3.5 commutator segments, Im unsure how close the adjuster allows them to go. Your comments or specs or data???

John T
 
Hey John - I memory serves the 3rd brush should not be set closer than 3 commutator bars from the fixed brush.

Incidentally my experience with these generators is the 3rd brush holder cannot be set closer than 3 commutator bars anyway. So you simply run it to the end of the adjustment and lock it down.

Bob M
 
Thanks for the good advice. I'll check the system over thoroughly. The generator is Delco and a newly reconditioned unit. The VR is also new. The belt is new. The wiring is all new and everything has been carefully grounded where required. I fitted ground wires back from each light and from the VR, so that everything runs directly back to the positive cable.
The tractor starts easily every time and the battery doesn't seem to have gone flat yet. I get 10amps showing on the ammeter with the lights off.
The C39 generator I referred to is fitted to my Farmall M, which runs a complete Lucas system. It works well, but it is a real nightmare to set up the regulator connections.
Thanks again.
SadFarmall
 

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