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MG TD TF 1500 - Need help with battery

I just bought a 1954 mgtf. It came without a battery. I just bought a new battery and need help:

1. Standing in front of car at the front bumper, looking at car, is the positive terminal on the right? What does positive ground mean?
2. Should I buy the wooden battery tray replacement for the one that is missing? Does it serve a function?
3. There is no hole in the new battery's post to screw down into. Does the screw do the work or do I drill a small hole?
Ed Eastman

Positive ground means the Positive terminal of the battery is connected to Earth (car metal body).

Battery tray doesn't really do much that I can fanthom, other than cosmetics and protecting the metal from spilt battery acid.

Remember that if the car was previously converted to negative earth, you will need to "flash" the dynamo to get it going. If the car has been standing without the battery for a long time you will need to do that anyhow because the fields(?) will have lost their charge.

For further instructions go here: a dynamo
Willem van der Veer


Most early (pre-1960) English cars were positive earth (ground to the Yanks). This means that many of today's electical auto accessories like a modern, solid-state radio will not work. What's more, it's likely you'll damage any such device, unless it is an accessory uniquely servicable with a positive earth application.

When connecting your new battery, and standing at the front of the car facing the windscreen, and with your battery positive terminal on your right, the wire leading from the ground strap on the right, originally connected to a simple bolt on the metal side of the battery case, should be connected to the positive terminal of the battery.

The other, negative side of the battery terminal on your left, should connect to a cable that normally goes on the left to the starter switch.

Many owners have changed their T-Series polarity to negative ground and replaced the generator with an alternator, but this obviates the rev-counter and another solution for the rev-counter has to be found.

With the production of the MGB, the polarity was changed to a negative ground like the Amercan cars, and all use alternators, unlike the early MGs that used generators.

Hope this is clear.

Gord Clark
Rockburn, Qué.
Gordon A. Clark

A slight correction to Gordon's statement that "most pre 60s British cars were positive ground", This only applies to the T series MGs (I can't speak to other British marques). The prewar cars were negative ground. I had a fuel pump cusotmer with a NA tell me this and checking in the Blower's manual, I found this to be true.

That said, what Willem and Gordon stated regarding the orentation, hook up and polarization of the generator is correct. If you are using the helmet style battery connection, the screw should start itslef in the battery terminal. If it doesn't, then drill a small hole no more than 1/4" deep for the screw to start in. Cheers - Dave
David DuBois

Ed, the decision of going positive or negative ground is totally up to you. The generator of the TF can be polarized to work either way. Whichever terminal you choose to ground should be on the right as viewed from the front of the car. An advantage of having a piece of wood under the battery is in providing clearance for the heads of bolts used to mount an after-market heater.
Bud Krueger

ed, the positive post of the battery to earth is on the drivers side(left), what type of a battery clamp are you using? the clamps on the battery cables should go around the posts on the battery. they are the type that uses a bolt to tighten the "C" shaped clamp. tom
tm peterson

For what it's worth (like everybody says this has been subject of debate several times on this BBS) ..up to you if you want to be "Poss or Neg" ground! If you haven't done so yet ..sign up as "a member" so you can search the archives...lots of arguments for both! that we have that out of the way, I can tell you I opted for the "plastic acid proof" battery box they make for the TF and have been very happy with it. Depending on what battery you go with you can end up with a nice little storage space for some oil, ect.

Buds "T-Talk" is so nice to have as a picture is worth a thousand words! (Thanks Bud)...look here:

Good shots there of "Izzys" box! Answers to the questions it will bring up!
#7427 is NEG Ground car.
The "red knob" is a cut-off on my "POSS" post. (I dipped a green one in tool grip so it would be correct color)
It is an "Interstate" battery (was green & white) I painted it black and put a "Lucas" sticker on it cause I was too cheap to spend bucks on a "TAR-TOP" repro!
I fill the old "period type" tin Marvell Mystery Oil container with Castroil 20/50 because it looks neater that a modern plastic one!
The "spare plug" holder is a period accesory (for TD) I bought from an auction and fitted to the battery holddown.

Hope I didn't totaly confuse you!
David 55 TF1500 #7427
David Sheward

Just wanted to add that you might want to be sure and use a star washer under that ground bolt connection to the battery box on the firewall. If you have a fresh paint job there, the paint can sometimes lessen the flow of current through the body and chassis. Also be sure to replace the two rubber buffers behind the battery - these help position the battery.

This thread was discussed between 08/05/2006 and 09/05/2006

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