Positive Ground ?'s

[jeepfiend]

I recently purchased a 1960 Series II. I have a couple of electrical system questions... I know the truck was originally positive ground. When I purchased it, the battery was hooked up in the conventional manner (neg. ground). I drove the truck, and it wasn't running really smooth, but I attributed this to the fact that it had been sitting for a number of years. I checked the charge with my meter, and it was putting out 14.7 volts and the meter indicated it was positive (with the positive lead from the meter on the positive terminal of the battery). However, my ammeter, in the dash, shows that it is discharging (I am assuming that the wires on the ammeter never got reversed). I am wondering if the coil wires also did not get switched, or perhaps the buy I bought it from just did not put the battery in correctly. But the question is, would it even start if the battery was backwards? Wouldn't the starter want to spin backwards??
Thanks
Kris

 

[LR Max]

If there was something backwardly installed, your vehicle wouldn't turn on.

Positive ground means that the positive lead of the battery is grounded to either the chassis or engine block (probably chassis). I'd check this first just to lay down the basics that your vehicle hasn't been converted yet. All the same principles still apply, just that the positive lead is connected to the chassis.

As for the ammeter, there is a possibility that it isn't properly hooked up/corroded connections. This would cause a false reading. BTW, when you checked with your multitester, was the vehicle running? If it was, then the 14.7 volts indicates a healthy generator.

If you had a bad generator/alternator, run the vehicle as much as possible for a couple of days with lights, radio, etc on. If you have a bad generator/alternator, you'll recieve an education in that time period (BTW, carry a spare battery in the back/jumper cables or something).

Check the wells in your battery. visually inspect to make sure they have water in them. I think its cell 6 or 8 (?) that usually gets low. If its low, replace with distilled water ONLY. Don't use tap water, this is not happy.

As for the rough running, I say do a basic tune up. Throw the timing light on it, recheck all ignition connections, and regap/clean spark plugs. If you are brave enough, then play with the carb. What carb do you have? Rover carbs aren't exactly the greatest part of the entire vehicle.

If you wish to check your coil, take your voltmeter, and place the positive lead on the positive side of the coil, and the negative lead on the negative side of the coil. There should be 12v going through it. Also check to feel if the coil is extremely hot. If so, this is an issue.

If you get bold, you can convert to negative ground:

http://www.lrfaq.org/Series/FAQ.S.elec_positive_ground.html

 

[jeepfiend]

I am pretty sure it has been converted. I got thinking about it, and if the battery was in backwards, it would not start. Mainly because the starter could not engage. If the starter motor spins backwards, the bendix will not engage and only the motor will spin.

The carb is a mystery. It has a tag that indicates it is a Chevrolet carb. I am guessing it is a Rochester.

I figured on the tune-up. I am actually going to install the pertronix ignition (don't worry I will keep a spare set fo points). I am fairly certain the ammeter is not hooked up correctly. I did check it with car running and I was impressed with the 14.7 volts, and it was at the correct polarity.

Don't worry, I know about using distilled water in the battery. I have been working on cars for a long time, but this is my first encounter with positive ground. I do need to still check the coil and make sure it is getting the proper voltage. Right now I am doing the groundwork to get the Series up and running. I don't have space in the garage until I get the engine in my Range Rover and get it out of the way.

Once I can get it in the garage, I will correct the wiring issues I find. I haven't told my wife yet, but this thing is about to get stripped to the bulkhead. She may not be too keen on that... I suppose I had better put the shocks and springs on her Discovery before I tear the Series down...

 

[antichrist]

The starter doesn't care if it's + or - earth, same part number.
If the coil leads aren't reversed when converting, the spark will jump backwards on the plugs and erode the center electrode quicker, eventually resulting in rough running. However, if the polarity on the generator isn't reversed, it won't charge. Sounds like yours has been converted properly, with the exception maybe of the ammeter, and possibly the coil. All lights and stock switches will work either way.