View Full Version : TR2/3/3A tr3 battery with positive ground

05-01-2006, 10:54 AM
On a tr3 battery with positive ground are there any special considerations to utilize to stop/lesson corrosion. I have left this vehicle original and it starts and charges fine, but there has always been more battery corrosion than I would like. Perhaps I need to maintain the battery more with baking soda or something. I do not know; I keep the connections clean, but that does not seem to be enough. I thought perhaps it is the positive ground itself because it seems to me that when it is raining a lot and dirt and oil get in contact with the system it could ground out. I guess in many ways, I do not completely understand the positive earth system. I see how the vehicle is its own entity sitting on the rubber tires, but it seems to again that driving in the rain would make at least a bad weak connection causing shorting. I do not know but any advice will be appreciated.

05-01-2006, 01:40 PM
Hello SP53,

it helps to coat the terminals in petroleum jelly to reduce the verdigris.
As to positive or negative earth, it only applies to the vehicle itself, forget any contact with the road that is irrelevant.


05-01-2006, 03:36 PM
"Earth" and "ground" are just terms that mean the side of the circuit that uses the body of the car as a conductor. It has nothing to do with the "ground" beneath your feet.
All metal vehicles use the body as a conductor (I'm sure there are exceptions, but for the sake of this discussion...) But regardless of the polarity of the chassis, it's only possible to short it to something connected to the other side of the battery. It cannot short to "ground" meaning the actual ground, as that is in no way connected to the battery.
A positive ground system works exactly like a negative ground system. The polarity is just reversed.
Testing is the same, components work the same, everything is the same, you just need to be consious of the polarity before hooking anything to the system.
As for corrosion, it's possible your battery is leaking acid around the terminal post. Get some terminal claeaner with acid detector. It turns red if there is acid present.
If so the only semi-perminant solution is to replace the battery.
But I second the petrolium jelly idea, that works well. also just paint the terminals (except where they contact each other) That helps cut down the "flower garden"
Good luck

05-01-2006, 04:07 PM
You can also buy terminal protectant spray in any auto store.

05-01-2006, 04:21 PM
Try the felt rings in conjunction with a terminal protectant. As explained to me, the gases escape the battery through expansion and contraction. The plastic case does not react to temperature at the same rate as the lead terminal. Hence, gaps open allowing the gases to escape.
The felt rings were popular in the 60's and 70's, and are saturated with an anti-corrosive. Any gases that get passed the felt rings should not be able to penetrate the protectant.
I use this system on my cars and have eliminated all corrosion problems. The rings should also be available at an auto parts store.

05-01-2006, 05:22 PM
Perhaps it's time for an AGM Battery. (https://en.wikipedia.org/wiki/Absorbed_Glass_Mat) I have one in my '92 Miata. It's sealed and there is NO corrosion, no maintenance, very slow self discharge rate when sitting long periods of time. And, it's the original battery that came with the car! Yes, it's 14 years old and still going strong. I'll be putting one in my TR3 when the resto is done. The one in my Miata is a Panasonic, but the most widely available AGM's are the Optimas.

05-01-2006, 07:49 PM
I'm kind of surprised to read this...on my '59, which I've kept positive ground (so far), I haven't had a hint of battery corrosion in the past year and a half. I'm using the original battery cables, w/ a brass disconnect on the negative side. This is the one area of the car I've not had to revisit, preventative-maintenance wise. I use a $35 Costco battery, which is made by Johnson Controls... go figure...
I use corrosion inhibitor,a purple gel-type stuff, on both daily drivers, where I've seen more corrosion. Maybe because of the disconnect, there's less chance of corrosion to form?

05-01-2006, 08:31 PM
I bet the biggest difference between you two is climate. Los Angeles-vs- washington state.
It's gonna be colder and more humid in Washington (most likley) and It probably also depends on how much each car is used, and how it's stored (heated garage-vs- non heated) This all adds variables.

Don Elliott
05-01-2006, 08:33 PM
I never had any corrosion since 1990 when I made sure that the control box was adjusted to 13.5 volts (or whatever it says in the manual). If it is putting out more than the specified volts, it'll overcharge your battery, spit a lot of hot battery acis all out the caps and cause corrosion and leave residues. See attachment.