Positive battery cable original length and routing on '47 DeSoto

[DeS-11]

Working through my newly-acquired '47, I noticed that the positive (ground) battery cable that was on it was too short to attach comfortably, with too much tension on it (and had a negative-sized terminal, at that). So I'm planning on either having a 1/0 replacement made, or buying one of the premade ones in that size. What I need to know is how it's supposed to be routed: does it go from the stud under the generator and then out behind the generator, curving back up to the battery, or should it go from the stud, downward, and then up to the battery--or some other way? It's hard to tell from photos, and it seems that many have been changed over the years, but I want to try to get it right the first time around as cables of this size aren't very forgiving. If anyone knows what the factory length was, as well as the proper factory size of the stud-end terminal, that would also be greatly appreciated. Thanks for everyone's help with all of my questions so far.

 

[DonaldSmith]

I've bought 1/0 cables from Tractor Supply.  Keep the connections clean, and they should work fine. 

I bolted the positive (+) ground cable to a bolt at the generator (alternator) bracket.  2 foot length should be enough. 

 

(I have disconnect ends at the battery. 

More surfaces to keep clean, but easy to disconnect the battery cable when the car is in storage, so that the clock doesn't run down the battery. . 

But lately I have a trickle charger, so I leave the battery connected. )

 

  

[DonaldSmith]

TSC "1 Gauge" cables.  

[Sniper]

Rockauto sells premade battery cables for  use, if you want something more factory made looking.

 

https://www.rockauto.com/en/tools/electrical,battery,battery+cable,2500

[DonaldSmith]

Be careful of the gauge.  The higher the number, the thinner the cable  (more cables fitting in a defined circle.) 1 gauge is fatter than 2 gauge, 2/0 gauge is fatter than 1 gauge.   Some of the guys swear by 2/0 gauge.  1 gauge is stock, and is adequate, in my experience.   

[FarmerJon]

I just replaced the 1 gauge cables on my Plymouth with custom made 2/0 cables. Huge difference in cranking speed. It always started fine, but cranking seemed labored. The 2/0 cables spin the starter almost as fast as 12v.

I had the cables made (3 in total, dont forget solinoid to starter!) By a shop on eBay:

https://www.ebay.com/itm/131905856172?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=_6ssZSI8QAe&sssrc=4429486&ssuid=m4Nb5uF4SzG&var=&widget_ver=artemis&media=COPY

The 3 cost right at $60, much cheaper than what I priced out at TSC or Big Box Auto parts. I ordered on sunday, and had them Wednesday afternoon, even though they made my positive cable custom (black insulation with red heat shrink)

[Sam Buchanan]

I'm another vote for the custom-made cables. Mine came from this vendor which I suspect is the same one that is also selling on eBay since both are coming our of Kentucky. My cables have 1000 strands which make them very flexible, the workmanship is first class and the price is very reasonable.

 

https://www.batterycablesusa.com/1-0-gauge-battery-cables-0-awg

 

I bought the battery cables, starter cable, and a ground cable for the body.

 

[Doug&Deb]

I also endorse custom made cables. A local shop that specializes in automotive electronics made them and rebuilt my starter. Definitely cranks faster. Also adding ground straps will help. They can be hidden if a factory look is important.

[DeS-11]

Thanks for the ideas; those look great. So for those who use the stud under the generator as a grounding point, could you tell me how you route the cable up to the battery? Also, what size terminal did you use at the stud end of the cable?

[Plymouthy Adams]

the original concept is the correct head style head bolt in the right location for the grounding lug to be affixed.

 

 

[Sam Buchanan]

Certainly nothing wrong with using the stud you mentioned, but there is nothing sacred about that particular location. The bolt you see being used in my photo that secures the coil bracket is commonly used because it doesn't penetrate the water jacket and is easily reached. My car originally had the ground cable attached to one of the thermostat housing bolts but I prefer a bolt that isn't in the water jacket and is less likely to be subject to corrosion and a less than ideal connection.

 

Main objective is to get a solid ground connection to the engine, location where you accomplish that is your preference.

 

Measure the diameter of the bolt/stud you intend to use to determine the size of the cable terminal. I checked my paperwork and my cables have 5/16" lugs.

Edited June 25 by Sam Buchanan

[Plymouthy Adams]

many fail to realize before teardown there are a few special head bolts that serve purposes such a grounding and the affixing the brackets such as those for the oil filter.   You can ground it where ever you wish for sure....but in no manner should one need to ask how to run a cable to a point not stock.....you do the change, you do the routing....just that simple.....I am far from being a purist but I also think if you need to apply a little common sense now and then just as you did Sam changing your point and running the cable as needed......why make this hard?

[Los_Control]

I was always told by my Uncle ...... If they are too long, just wrap them around the dip stick tube a few times ..... works for both battery cables and plug wires.

[DeS-11]

 

21 minutes ago, Plymouthy Adams said:

but in no manner should one need to ask how to run a cable to a point not stock.....you do the change, you do the routing....just that simple.....I am far from being a purist but I also think if you need to apply a little common sense now and then just as you did Sam changing your point and running the cable as needed......why make this hard?

 

I thought that the generator stud was the stock point (I had seen posts on here in the past mentioning it), so that's why I was wondering how the factory would have routed it, as there could be several possibilities. Your attachment point is definitely cleaner, though, but I'm starting to think that the different Chrysler divisions may have all done it differently, depending on the year. I just want to try to get it right the first time around, since everything is too expensive now to be making mistakes or buying things twice.

[Plymouthy Adams]

for sure on the cost of backing up.... but just trying to point out no matter where you chose the ground point on your engine...it is also not at all difficult to route the cable to that point.   It is just natural you find a good clean point to connect and at the same time visualize the path of the cable.  Length and cost of cable being the main issue with alternate points.   IF you can find some good grade star washers, these are a great help for good connections.  Be careful on voltage drops on cabling especially on a 6 volt system.  

[Plymouthy Adams]

this is from an online phot of 47 desoto.....check out the battery cable mounting position......while it does not definitively show the front head bolt.....it is close enough for me to believe this is true

 

Edited June 25 by Plymouthy Adams

[Sam Buchanan]

Just for clarification, if your Desoto doesn't have the special head bolt for the ground cable lug DO NOT remove a head bolt just for the purpose of attaching the ground cable. You will tempt the Unintended Consequences gremlins...they can be ornery!!  😄

 

This whole deal is being waaay over-thought........

Edited June 25 by Sam Buchanan

[Dan Hiebert]

The ground cable on our D24 is to a stud (5/16) on the generator mount.  The cable is routed under the generator to a built in (ergo - "factory") wire clamp on the inner fender, then forward and upwards to the positive terminal of the battery.  That is not where it was when we got the car, it was straight from the terminal to one of the thermostat housing bolts.  I don't like that look, found that stud on the generator mount, and changed the ground to that location with what to me is a cleaner routing.   As noted, don't over-think it.  Theoretically, the shorter the cables the better, but with 1 gauge cable the length isn't a concern in these cars.  Use the right gauge cable, and route it where you like it.  NAPA can build battery cables for you, too.  They do here, anyway.  

[DeS-11]

Thanks, Dan; that's what I was interested in knowing specifically--how the factory likely would have done it originally. I'll look for the clamp on mine when I'm able to get back to it. Sam makes a good point, as well. I appreciate everyone who took the time to reply.

[Plymouthy Adams]

2 hours ago, Dan Hiebert said:

.......it was straight from the terminal to one of the thermostat housing bolts. (in part)

anyone grounding the battery through a thermostat housing bolts should not be allowed to own one of these old cars much less be allowed to work on it....