Electrical: Electrical Curiosities & Fuel Pump Levers

[Youngstudedude]

Hello All,

This one might be a little long. I'm a few months in the process of getting my 49 commander on the road and have been experiencing some interesting phenomena with the electrical system.
The car is still running on 6v and has a 1month +/- old battery, all the lights work and have tested the generator and get a consistent voltage increase when running the engine faster than idle.
Here's the problem. After a few days of city driving the battery is so low on charge it is very had to get the engine to turn over fast enough to start. With just the right choke and taps on the accelerator i can get it to go but end up bringing in the battery to charge overnight on the trickle. Then a few days later the same happens again.

My question is, am I asking too much of the generator in the city? I know on some of these systems you need to run a good 15-20 mins highway to get the charge up. Is there a rule of thumb to follow per start for how long it will take to re-generate the electricity that has been used?

The 2nd thing which is kind of odd has been the fuel system. Currently the mechanical fuel pump has been bypassed and a 6v electrical one is wired to the ignition. I have been having issues with these electrical fuel pumps going out and have installed a new mechanical one but when looking at the lever I thought it looked a little small in comparison to the original one. After install and filling the lines-bowl-and carb via the electrical pump, i fired up the car and the new pump didn't send any new fuel to the carb (car died once the carb bowl was spent). I also noticed that the new pump didn't have the vacuum unit on the bottom of the unit like the original one did. (I did test the pump out of car with fuel to make sure it was moving fuel and it worked great)

In this case I'm assuming I got the wrong pump and am wondering where I can source one with the bigger lever? I would rebuild the original one but someone had drilled in new larger holes for trough-bolts and that seems like that could be a problem in the future (damage the diaphragm). Also is that common to have a vacuum unit on the base of these pumps?

Any thoughts would be appreciated, thank you!

[PackardV8]

Hello All,

The car is still running on 6v and has a 1month +/- old battery, all the lights work and have tested the generator and get a consistent voltage increase when running the engine faster than idle.
Here's the problem. After a few days of city driving the battery is so low on charge it is very had to get the engine to turn over fast enough to start. With just the right choke and taps on the accelerator i can get it to go but end up bringing in the battery to charge overnight on the trickle. Then a few days later the same happens again.

My question is, am I asking too much of the generator in the city? I know on some of these systems you need to run a good 15-20 mins highway to get the charge up. Is there a rule of thumb to follow per start for how long it will take to re-generate the electricity that has been used?

Any thoughts would be appreciated, thank you!

No, your generating system not functioning correctly. It should recharge and hold a charge indefinitely.
Yes, you may have a bad battery. We've seen some less expensive 6-volt battery quality is not what it once was. Some of our members have had better success with AGM batteries.
Maybe, check your cables and wiring connections. The #1 cause of 6-volt problems are corroded cables and connections or thinner gauge 12-volt cables being used incorrectly.

jack vines

[41 Frank]

Maybe you were sold a fuel pump for a Champion "6" engine rather than a Commander "6"

[TWChamp]

I also think you may have a Champion pump. You can buy a Commander pump fairly cheap on ebay, then buy the modern diaphram kit from a Studebaker parts vendor. I bought my modern diaphram kit at the South Bend swap meet a year ago, and the pump works great. BTW, it's a dual diaphram pump, as you also had.

My generator keeps my 2 year old battery charged, even at idle. When my 50 Land Cruiser sets for 6 months over winter it will take several seconds to prime the carb and fire up. This may take 10 to 20 minutes of driving to make the ammeter return to just a hair over the 0 mark. Other times the car fires up as soon as I hit the starter button, and the battery will be recharged in a few seconds. I always use a quality original generator and voltage regulator, even if I have to buy it from a junkyard Studebaker.

[Youngstudedude]

Thank you Jack for the AGM tip and Frank + TW champ for the champion pump diagnosis and for looking on ebay.

Ill do a better assessment of the battery condition and get it tested. The only place I could find that had 6v near me was the auto zone and they had.... Duralast #amazing so will see where that puts me.
Do you think the cause might be the constant draw from the electric fuel pump? It knocks the needle over before the car is fired up. Then holds @ neutral until the revs kick in. Also when the headlights
are on there is a very large draw on the current and slowly goes from negative amp draw to positive until the revs are past 3k (estimation since there is no tachometer)

I did a Ebay search and found 3 options:

https://www.ebay.com/itm/1948-1949-S...MAAOSw~hBc2iEV
https://www.ebay.com/itm/1948-1949-S...YAAOSwv-ZaLVbe
https://www.ebay.com/itm/Rebuilt-AC-...4AAOSw~VBcPj~v

#3 looks like the best option price-wise with a rebuild anyone bought from these sellers before?

[nvonada]

You said you had consistent voltage but not what that voltage is. 7.2V at the battery is about right. If you are not charging on the ammeter until 3K that is not good. With no load my car is neutral at idle and charges as soon as any revs at all are applied. With headlights on I am at a slight discharge at idle As was said before 6V systems are more sensitive to bad connections and need thick cables but they work just fine. You pump may be a contributing factor. Disconnect it temporarily and see!

My last battery was from NAPA and started to get weak at over 9 years old. I just bought a Rural King battery (made by Exide) and we will see. It was $30 cheaper so if it only lasts 6 years I am ahead

[Mrs K Corbin]

How big are the battery cables? they should look like Goucho's Cigar, not the little 12V modern cables. A must for 6V systems.
Clean the ends of the cables (both ends), as well as the ground strap from engine to frame. Plus clean the mounting points. that Helped me out.

[tsenecal]

Sounds like you need to remove the fuel pump, and compare it side by side with the one you took off. That should verify whether the arm is correct length and shape. Good luck with it.

[Youngstudedude]

Howdy all,

Looking at these battery leads I'm pretty sure they are a little too dinky for the system. The fuel pumps on eBay look great and have the correct shape to the lever so will be ordering soon.
I'm hoping the extra amperage saved from the 6v pump may keep the battery happy especially after the cables are beefed up.

Thank you all for the tips!

[altair]

If the fuel pump was from a Champion 6 it would not work because the actuating lever is about one inch shorter and would not touch the cam. Cable size is important for starting at least 0 or 00 and to assure good continuity connect your ground cable direct to a starter bolt. A generator on test uncontrolled will put out 40 + volts, controlled at the generator about 7+ volts. You should attain the 7+ volts at the battery just above idle 600-800 RPM.Above Champion 6 pump.
An electric fuel pump will not drain a fully charged battery even if it ran for 30 minutes. To assure continuity between the generator and the voltage regulator I recommend connecting a jumper from the generator housing to the voltage regulator housing. Some cars are wired this way and some not.

[Youngstudedude]

Update:
Swapped in a new ground wire and it has made a HUGE difference in recharge time. The starter is kicking over faster now but am still having some "ungraceful" (slow to go) starts.
Will post once the new pump gets in! The one that I swapped out for originally was the wrong one.

Thank you everyone!!

[Mrs K Corbin]

Once I saw the picture you posted, I knew that the Positive Ground Cable was way too small....

2 things to check at this point:

take a mustard bottle and pour about a teaspoon of gas down the carb throat just before hitting the starter. (Keep a fire extinguisher handy).
If it immediately starts, you've most likely got a fuel system problem. Also check to see that your choke closes properly. I thought mine worked as the knob on the dash would pull out and the linkage worked on the carb, but something internal was stopping the choke from closing completely. I removed part of the linkage and it works fine now.

Next: With someone holding a multimeter on the coil (Low voltage) to ground, check your voltage while cranking...

Also, clean, clean, clean all the electrical connections in that circuit. I've seen many a problem that was just a little corrosion on a connection somewhere. Drive you crazy till you find it.

[Youngstudedude]

Howdy all,
So Ive been nearly a week now with the new fuel pumps [electric + mechanical] and what a world of difference. The car really has some gusto now and can open up when necessary. I went through the wires and cleaned everything up as best as could be done.
Starting is better and the amps returning to the batt through the new cable get everything stabilized and recharged in under 5 minuets. That said it really is a gamble with how the car would like to start. the battery I currently have has a 570 cc amp output
and it seems to be lacking a bit as far as how fast it kick the engine over the fuel situation is good with plenty of pressure. Would on of those optima AGM batteries be the key to easier starts? The one I see available has 800 cc amps and looks considerably better than the cheapo one I have now.

In other news I found a leak in the exhaust manifold and swapped in a new one. Apart from the iffy starts the car is really running great!

Thank you in advance for any advice

[nvonada]

Your battery is plenty good enough if the rest of the system is solid. You need big, good, clean cables and connections. Measure the voltage at the battery, starter switch, and starter (with someone cranking). Every bit of voltage drop is power being robbed from your starter. Check your engine ground strap. Bad ground between the engine and frame will cost you too. A fancy battery might start the car better but it is just masking problems.

[tsenecal]

I have run the Optima 6 volt battery, and it worked well. The cranking amps are higher, but as others have said, you will need good cables and connections to get that amperage to the starter. If you have a cable that is to small, or a bad ground, the amperage will just create more heat at that point of resistance. Good Luck with it.