6 volt starting issues )=

[franek25]

Hello my name is jason hope all is well with everyone. I have run into another issue. I am new to older cars but with help from al lof you have made much progress. I have a 1937 cadillac that used to start but the craking power was always crapy at best. I found out that the battery cable should be at least 2/0 and it was only 2 gage. so jst switched that out and made a much better ground.  The issue I have is the motor still starts very slow like its tryingto get up a hill for ten seconds then finnaly starts coming down the hill but still slow. I removed all the spark plugs to see if something was stuck or binding and the starter flys around fast. I then put spark plugs back in then slow start again. I jst refurbished the carter wdo carburator and am trying to adjust it. But since the starting issue is crapy i only get about 20 seconds of craking before the battey dies agian not giving the car enough power to even start. I have a  brand new battery goes dead and wont even turn the car over at all so it goes back on the charger  for another few hours then i get two more goes at it.   been very frustrating  and a lost cause I am at a loss. car ran great before new carb . pllllleeeeeaaassseee help )=

[James Gray]

Jason,

Me again. Just posted on your carb issue.

I have the same startingissue. I bought a new battery from Pep-Boys. That was a mistake. I have an emailed link to a great battery source for these old cars. Much better cranking power than a typical 6 volt battery. I will post that here when I get home to my PC later this evening. The battery replacement for my car is $295.00. They are not cheap. There is a case which you can purchase which makes the battery appear to be OEM as well. I haven;t ordered mine yet but am told it makes a significant difference when starting.

The best fix is like I said in the other post. Make sure all of your electrical is as best as possible. This helps the engine fire better and faster. Once I got mine set, it stated much easier, even with the crappy battery. Likely because with good electrical, on the initial cranking when there is minimal fuel for combustion, the good electrical helps rotate the engine over faster until enough fuel is available to run. Remember, this is a carbureted enginge and not fuel injection whereas fuel pressure is established immediately.

And again, I am no expert.

[franek25]

thank you (=. I got a optima 6 volt battery I read they were good but not sure now. I took starter off and it looks to be in good order but ill take another look. It used to start very easily with a small spray of starter fluid but now that is not working.
)= ill start tonight with trying to check coil and points and see if i am getting spark to the plugs . Hard to do it alone but ill have a go at it. Ill figure something out The fact that it wont even fire with starting fuid makes me wonder if its something other than the carburator. Maybe there is a vacume leak when i put the carb back on it dident seal correctly. Well seems like i got some work ahead of me !! thanks again guys (=

[KD]

My 1940 V-16 was the same way even with a new battery. I connected the ground to the bolt on the starter and had the starter rebuilt. That made it spin like a 12 volt system. Take off your starter and have it checked, they can tell if there is a problem with it . I'll bet there is.
KD CLC#26801

[Michel Ouellette]

Hi Jason, those cars are suppose to start with in a turn or two so the way of testing your system is first, disconnect the wire from coil to distributor, then, ask somebody to go in the car, put a voltmeter DIRECTLY on the battery post, NOT on the cables, ON the post, you should have 7.2 volts + -, then crank (start) the engine, if it goes lower to 5 volts, then the battery is wrong, secondly, put the voltmeter to the positive post NOT on the cable, ON the post and put the other end to the starter, again ON the bolt NOT on the cable or the nut, crank again, if you have 3 volts then the trouble is in between, do the same thing for all components like solenoid, between post and cables ( on the bolt and the cable )  what you will find is lost of voltage .3 .4.8 and so then clean or replace the defective, put all those info on paper and calculate your lost of power and you will find your answer!.
Hope this will help you and other folks.

Michel 

[James Gray]

Now here's a man with good knowledge to share. It's people like you and a few others I've obtained great information from.
Thank you

[bcroe]

Hi Jason, those cars are suppose to start with in a turn or two so the way of testing your system is first, disconnect the wire from coil to distributor, then, ask somebody to go in the car, put a voltmeter DIRECTLY on the battery post, NOT on the cables, ON the post, you should have 7.2 volts + -, then crank (start) the engine, if it goes lower to 5 volts, then the battery is wrong, secondly, put the voltmeter to the positive post NOT on the cable, ON the post and put the other end to the starter, again ON the bolt NOT on the cable or the nut, crank again, if you have 3 volts then the trouble is in between, do the same thing for all components like solenoid, between post and cables ( on the bolt and the cable )  what you will find is lost of voltage .3 .4.8 and so then clean or replace the defective, put all those info on paper and calculate your lost of power and you will find your answer!.
Hope this will help you and other folks.  Michel   

When this precess is complete, you should have good voltage to the starter.  If it STILL cranks poorly,
do check the starter brushes.  Bruce Roe

[Jay Friedman]

Two more suggestions that may help:

1. Take off the starter and make sure there is no paint either on the surface of the starter where it is mounted to the motor or on the adjacent surface of the motor;

2. Have your starter rebuilt with heavy duty field coils.

[Richardonly]

If the car can run (after numerous tries)  put a timing light on it and make sure it is what it should be.  This test only will take a minute or two and will rule out a worn or jumped timing gear/chain.  (This can cause the problem you are having.)

Richard

[franek25]

thank you everyone for all your feedback I will do as directed and see what happens (=. The motor runs beautifully once started since it only has 200 on rebuilt motor. then it sat for 10 years when th eman passed who was restoring it. With all your help i am sure i will figure out the issue. thank you all agian so much now i have somewere to start. i am a first generation old car nut haha !

[Doug Houston]

Ken Dennison, a few messages back, has the solution to this problem. I have just written an article for the CCCA Michigan publication: TORQUE, on this very topic.

My solution to this is to install a 3/8" bolt on the commutator end plate of the starter motor, and connect the battery ground cable to that bolt. the commutator plate is the point where the actual starter is internally grounded. It as done that way on my '41 Oldsmbile, but how come not on other cars?

I have two Cadillacs series 90 (V16), but on is a '38, and the other a '39. Boh have batteries beneath the passenger side of the front seat. The '40 Cadillac 90' have the battery on the outboard side of the frame, alongside the starter motor. I have made new cables for connecting the battery to the starter, from #2-0 welding cable. The battery will be connected directly to the starter on those cars. I expect good results after installation.

I'll try to attach a picture of the hookup on one of my '41 cars. Ultimately, all of my cars will have the grounding stud on their starters.

[franek25]

I will try that as well. Thank you for your responce it makes sence. last night I  removed the stater in 10 min (=  and sanded down any paint that was were the starter and the motor meet. I also check the bushings and one of th escrews was loose . I put the starter back on. I then checked the voltage with the battery at satnd still and it read 6.34 volts. when i pushed the starter button with the coil wire off  it went down to 5.54 then with coil on same 5.4volts from battery. Not sure if tha tmeans battery is bad or not. I put coil back on and did see a change in how the starter mortor rotated it did improve.

I think the problem is also even though  Installed new 2/0 welding cable the the battery is about 5 to 6 feet from starter located under drivers seat. i wonder if making a bracket to install the battery in engine compartment and getting ground and pos cable clser to starter if that would work as well. just seems like a long way for the current to travel. Any opinions on that. I think grounding wire stright to starter would work to improve amps ?? like described above

[Bill Ingler #7799]

Grounding direct to the starter as Doug Houston has suggested, using double 0 welding cable will give you the quickest remedy to your slow start. Remember the motor mounts, the engine is sitting on, is cushioned rubber and rubber is an insulator not a conductor. Temporally you can, as has been posted, ground the battery to one of the 3 starter bolts. I personally prefer the Optima battery for the high cranking amps plus it weighs less than 20 lbs which beats the hernia producing large commercial battery that I once had in my 47. If you follow the guidance posted by others, your car should start, hot or cold as good as when it was when new, using 6 volts.      Bill

[Doug Houston]

While I haven't seen every Cadillac...........!, the engine is usually boded to the frame with a flexible strap at one or both of the front engine mounts.

Understand that the starting motor will have a few MICROHMS resistance from one end to the other. This is what normally causes the voltage drop when the battery ground is terminated at other than the commutator end plate. I have measured as little cranking current of 175 amperes, and as much as 500-600 amperes.(at more than 300 amperes, something is very wrong!)

However, if you ground the battery as I have recommended, The grounding path will go toward the drive end of the starter. Assume that the maximum current for the car's system would be 30-40 amperes, the small resistance through the starer becomes negligible under those conditions.     

Now, assuming that the grounding straps are present at the front engine mounts, the engine-to-frame  bonding is taken  care of. If not, straps should be installed to solve the problem.   

A few years ago, I worked on the Army' 5 ton truck program. I did most, or all of the electrical work on the truck (I'm a grad EE). Those systems start the engines on 24 Volts, and lo and behold, they ground the battery right smack to the starter's brushes!

I'll never know why the engineering staffs of the GM divisions never talked to each other on things like this.
It was never done on the cars that needed it the most!

[R Sotardi #11719]

Jason, I have a 1950. I went through a similar issue when I first bought the car 20 years ago. 1. Lose the "welding cable" You want 00. Most stores like Batteries Plus don't have this. They sold me a cable  that was too "thin" but I could not see since it was encased in insulation terminal to terminal. If the wire is too thin it will not spin the engine fast enough to create a charge in the coil... and a weak (if any) spark in the plugs.  Advice :call Y&Z in Redlands Ca or Rhode Is Wiring with the length needed. It is worth the cost. 2. My 50 is grounded in 2 places. Not just on the starter but in the middle of the cable it is grounded to the frame as well. Recommend: purchase the correct braided ground strap. All connections must be clean, with no "grease" etc. By an  6v Optima on Amazon for @ $125, if you have not already. You can buy a antique style case to make it look authentic ( see Quail Services). You are getting a big voltage drop that appears to be a current bottleneck. That is usually the cables, but if all this still fails bring the starter to a GOOD shop for testing. Did you just have the engine rebuilt? It could be a bit "over tight" and must be seated to reduce drag.  Ron

[franek25]

I plan on working on it tomarrow and trying to get everything grounded like you have described . i just never new how important grounding th ecar was. I guess i always took it for granted becaue newer cars you never really have to worry about it. I have noticed one strap from motor to frame but looked like it had paint on it and was n=bolted to part of the frame with paint on it. I plan on running ground from battery right to the starter also plan on moving battery closer to starter so its not so far away. After i do these things I hope it solves my issue . If it doesent I guess have the starter rebuilt (-/ Agaian thank you all for your imput I will keep you posted as to what happens nex (= have a great weekend everybody !

[Jay Friedman]

I'd like to end the discussion on a mildly humorous note by paraphrasing the Duchess Of Windsor who once said that "You can't be too skinny or too rich".  My adaptation of this remark is that "A 6 volt Cadillac can't have battery cables that are too thick".

Jay

[Doug Houston]

Another  version of that is: "If enough is good; too much is better"

In the case of battery cables, too big a wire gauge will never do any harm.

I have made new feed cables from the battery to the starter on my 38-90 Cadillac. There is one instance where the heaviest wire gauge will theoretically be the best. I once did an article for the TORQUE about those cables. All connections were soldered, of course, and while that starter has yet to be installed, I have high hopes for it.Th cables were done from 2-0 gauge welding cable. It's very flexible, and very nice to work with.

I'll be anxious to hear about the results of the starter in the original post here.

[franek25]

ok i am back and so far I have changed battery cables to 2/0copper welding cables for kicks and giggles i made some sorter ones jst so i can get the battery 2 feet from the starter to allow the positive and negitive cables close as possible to the starter. I ran another grounding strap from engine block to the frame jst for som eextra ground. Turned the key and it did spin allot better for 4 or 5 seconds  but started slow and slowly began to spin fatser by that point seemed like battery started to die. Then low and behold battery dead. )= I have tried to spin fan by hand and it is extreamly hard to do i am no a small weak guy and it almost takes all I have to spin motor that way. The motor seems very very tight. Is that normal ?? The rebult motor I was told only has about 100 miles on it or so could this also be a big factor?? I guess I am jst frustrated And at this point feel llike a 12 volt system is needed. Or should I jst stick with it and see about getting starter looked at. well hope all is well with you all and thank you again for all the help! Also i have the battery hooked up with positive ground is that correct ??

[harvey b]

It looks like you are on the right track with your cables,starting to look like your battery is weak,how old is it,how long has it been sitting in the car,as they get older they will not keep up the amps.My 37 which has the same mechanicals as yours,it spins over pretty good,my battery is 6 years old,but it is exercised a lot in the warmer months here?,A new engine can be tougher to spin over when it is fresh loke that.I made a custom battery tray for my car,original was rusted out,it wasn't even there to try to repair,what I did was find the largest battery I could find,then I made the box to put it in,it is under the front seat,My car is a driver so I don't care about the originality of the battery.Good Luck