VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt slow starting TURNOVER with 6 volts

hi there,
I have now arrived at the time to test start my car using the 6 volt system, previously it was test run on 12 volts and a 12 volt coil.

It now turns very slowly and I think that maybe there is not enough power left for a spark or two?

It has the original heavy cables to the battery and earth.
The starter was tested and serviced about 16 years ago, when I first became the owner of the beast.
Maybe it time to remove it and do the same again?
From reading other posts, it seems that earthing is very important with 6 volt systems, right or wrong?

Any ideas would be appreciated.

Peter

I've got a 48 Fleetmaster - with the 6 volt system. I replaced the positive battery cable with a heavy one, and, put a new battery in her. The negative was already a heavy one so I just cleaned it and re-installed it. I also ran an auxiliary ground from the rear bolt on the exhaust manifold to one of the mounting screws on the base of the voltage regulator. My car cranks just fine both hot and cold now. Yes, the ground is very important - you can check and see if you've got a good ground with a Volt-Ohm meter.

Regards:
Oldengineer
48 Fleetmaster Town Sedan

#1 make sure all cable connections are clean on both ends of both cables (no crud, no corrosion).
#2 make sure you have properly sized cables for 6v (minimum size 1 gauge/ 0 is better).
#3 test your battery-replace if necessary.
#4 test your starter-repair or replace if necessary.

Those steps will alleviate 99% of slow cranking problems.

Also, make sure that your 6 volt battery is at least 600 to 625 CCA.

I just had the same problem with my 33 starter.It turned over very slow with 6 volts,but spun great with 12 volts.After replacing the battery and making sure my cables were good,I found the starter was going bad.Took it to the shop and they installed new bushings,machined the armature ends to accept the undersized bushings,trued the commutator and installed new brushes.Total cost was $99.00 and well worth it.It spins like a charm now.Good luck with yours.

Hi there all,
thanks for the hints on what to do.
The battery is brand new deep cycle and about 600 cranking amps.
I will remove the starter and take it into the auto electricians, whilst there I will show them the main lead to find out if it is of a heavy enough gauge.
I will keep you posted as to the results.
Peter

I don't think you want a deep cycle battery.I may be wrong,so I would ask the more knowledged members on this site.I use a deep cycle battery on the electric trolling motor in my bass boat.I think they can store voltage over a long period of time,but I don't think they have the cold cranking amps needed to start an automobile.

I've read numerous places that deep cycle batteries are for slow, deep discharges & re-charges not supplying a lot of amps quickly as is needed for a starter motor.

Tiny is correct. A deep cycle battery is great for motor homes, boaters, and truckers who need slow discharge over extended periods for radios , tv's, microwaves, heaters and such, but for starting you want a battery with a high "cca" cold cranking amps rating.

hi there,
I used and was recommended to use a deep cycle battery for my boat many years ago.
I had a big HP outboard and it started it well every time, the reason that I had a Deep cycle was because a boat is not used every day as a car usually is.
my battery has the CCA needed and I guess that I now have to confront my auto electrician to explain your advices.

If you are right and the electrician is wrong in supplying me with the wrong battery , I will probably not have a hope in hell in getting a refund or replacement?

oh well, sh.t happens, as we say over here, next week will be the testing of the waters.......
peter

I installed an Optima Gel 6V battery in my 32 and what a difference. I spins over like a 12 Volt.

just an update.
spent lots of $ on having new cables made up in "O" gauge wire, new fittings and also bought a cut-out isolation switch to mount on the floor in front of the front seat.

Yesterday I connected everything up and tested it for turnover speed.
Alas even with the new pristine gear, the speed was about the same, rather slow.

I am used to hearing 12 volt engines turn over, my tractors, land-rover and a morris minor. I am thinking that I will find a car in our club that has a 6 volt system and have a listen to it.
Possibly what I am hearing is Normal?

At the same time I tested the lighting system and with the new dimmer switch fitted, everything is now working Dinky dory. The blinkers seem a bit slow, but then I am getting like that too...

cheers
Peter

Optima Gel...Deep-Cycle boat Battery...Regular battery...Doesn't matter...Should all work fine if there in good shape...I'd fool with that ground one more time...before blaming the starter...

If the engines are right they should fire and run on the first full revolution. Just remember they had a starting crank that would start them if the battery was low. And with a starting crank they don't spin over very fast. Or could be pushed in second or high gear for a few feet (just enough to get the engine to roll over) to get them started. Fast running starter just wears out parts faster.

Chipper has a good point.

In the olden days, I used to always have old batteries in my '31. (Couldn't afford to buy a new one very often.) The engine would turn over very slowly and often not start.

When that occurred, I rationalized that the battery was too low to turn over the engine AND provide a hot enough spark. So I got around that by hand-cranking my car. It would ALWAYS start that way. When you hand-crank your car, it turns over VERY slowly, BUT there is no battery draw by the starter -- so you get maximum charge to the coil.

Now, I am also a fan of making sure that three locations always make excellent contact:
1. Positive cable to the battery.
2. Negative cable to the battery.
3. Negative cable connection to "ground".

And as some folks have said, connecting the negative cable to the ENGINE is a better ground, than connecting it to the frame.

So... another point of view for you to consider.

--Bill Barker

hi there Bill.
thank you for your reply,
that is the first time that I have heard of connecting earth to the ENGINE and not the chassis!
I will go and re-arrange my earth and see what happens, and let you know the outcome. Thanks for the tip..
cheers
Peter

For a few years back in the 2000's my 28 was a slow cranker, despite all my efforts and what I thought was ok cables and connections.

Replaced a battery that did not need replacing, checked both battery terminals, they were fine, and I thought I had a good earth strap, a fairly new woven one.

Eventually the earth strap and a battery disconnect switch that is part of the terminal were the culprits.

The earth strap end end bolting to the chassis looked ok from the outside, but when removed was not so good, and I think the battery disconnect terminal was not making full contact.

Replaced earth strap with a shielded cable, with a big lug soldered, not crimped, and fitted a proper battery kill switch.

Cranking speed increased, dont know by how much, but was definetly faster.

Also I have always attached my earth cable to one of the bolts that hold the bracket from the brake cross shafts to the uni joint housing.

No problem since, and that was about 2009.

Cheers

Ray

hi Ray,
I have an existing earth strap from the uni housing to the chassis, My new earth is to a point just past that connection (freshly drilled and cleaned).

I am wondering if that I connect another earth from that existing uni point to my new earth on the chassis if that might help? and indeed create the earth that Bill explained earlier in this post?
(earth the the engine)??

Peter

Ray
The heaviest current will be from the starter so a direct "clean" connection from the engine to battery would be best. The engine does not have a good "electrical" connection to the chassis otherwise.

By all means put a second earth lead from the body/chassis as well for lights and such but this lead wont need to be as heavy though.
Tony

You could try another earth strap/cable from the engine to where the earth strap/cable is bolted to the frame. Also just make sure the area around where the earth strap/cable is bolted to the frame is clean to bare metal. I know you did it before.

yes I understand, both sides of the chassis are sanded and had a totally clean connection.
I need a beak from this, I am getting very weary.....
peter

One more thing to satisfy curiosity...Sometimes the timing effects the turn-over...Pull off the high-tension wire for one spin...I don't know, maybe it's firing to soon...? ...grasping at straws here...

If you have a camera that will take a video with sound maybe you could make a short video of it cranking so we can hear it. Maybe it's a normal speed for a 6v. Just a thought.

After re-reading all post I am curious if the car is failing to start. If the battery is 600-625 cca and the starter still turns too slow to start the car then perhaps its a good idea to check the draw on the battery when cranking. Your first thoughts may be correct that its time to rebuild the starter.

Good Point Kevin47,

If your timing is too advanced that can slow down cranking.

Cheers

Ray