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This may be a stupid question but I am finally ready to hook up the battery cables and check my electrical work.being a positive ground system,my new and old battery cable terminal won't fit on the new battery post.Any help is greatly appreciated,thanks

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Negative and positive battery terminals are slightly different diameters, so either swap the cables if possible or buy new ones (highly recommended).

I believe all the battery posts have been a fairly standard size with positive being larger but the cable terminals today are either "universal" or if ready made, most come with todays conventional neg ground - pos to system configuration. I believe Napa carries some cables in both configurations in their heavy duty truck section but you have to look for them. I wouldn't buy ready made in what stores call 6v cables today because those are marginal in size. Truck sizes are a bit heavier but if you buy a cable try to get 0 or 00 gauge for your 6v use. If it has a universal connector then a terminal spreader can open the positive up to fit and the clamping action of the bolt will close the negative down. You can get the cables custom made by many of the wire harness vendors and there you can specify which terminal to place on the cable.

While you are at it-you might want to come up with a way to disconnect the battery when not in use for safety reasons. I pull the lead off of one battery post when I shut down the car. I have tried the green knob and a knife switch disconnects both caused problems.

Thanks everybody,I do have new cables but the ground cable is to small for the positive battery post. Also I usually use the green knob cutoff but have had issues with those too

Although I'm down-under, just had to "fix" the photo!

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Also I usually use the green knob cutoff but have had issues with those too

Those little "green knob" gadgets are marginally OK for 12-volt systems but don't have enough contact area for the higher current draw of 6-volt systems. Though it's a bit more to install, the Cole-Herse type rotary switch remains the best.

I believe your problem is with the confusing terminology of positive ground. Ground does not indicate the negative terminal, it is a contraction of "common ground". The entire chassis/body (or the common area )on a positive ground car is + polarity. Thus the ground cable from the battery to the engine/chassis comes from the + terminal which is larger. This cable should be the flat braided type without insulation. The negative cable goes to the smaller battery post and is round with insulation covering it.

I think this will solve your problem.

The green knob shutoff switches will fit better on one terminal than the other

NAPA sells a heavy duty battery cable disconnect. One part clamps onto the battery terminal and the other is on the cable end. It uses a round knob to tighten the two pieces together. When the knob is loosened the cable can be separated from the battery. I have used them on my 6- and 12-volt Packards and they will handle the amp load of a 6-volt system. These are not the light duty green knob devices O_D talked about. These work well for safety reasons, but you may want to use a Cole-Hersey switch hidden from view for security.

I agree, get "O" or preferably "OO" sized cables. A braided ground cable is not necessary, a regular cable of the large size will work just fine. I like to attach the cable disconnect to the ground terminal and have a ground strap to connect the engine and frame. Good idea to have the body and frame grounded too.

(o{}o)