Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: mespe on February 07, 2009, 00:12:20

Title: Battery polarity question
Post by: mespe on February 07, 2009, 00:12:20
Hi all,

I bought a 1967 250SL, that had been in storage for years. The battery in the car was disconnected, but the red wire going to the battery (by the + terminal) is grounded on the chassis, and the black wire goes off toward the engine and starter. It looks like this car (a Euro version) has a positive ground. I did a search and found a thread that says all pagodas are negative ground. So now I'm completely confused,,,
Title: Re: Battery polarity question
Post by: jeffc280sl on February 07, 2009, 02:10:17
Everything I have read say the SLs are negative ground.  I have owned 2 of them and they were both negative ground.
Title: Re: Battery polarity question
Post by: glenn on February 07, 2009, 03:51:52
'in storage for years'
Title: Re: Battery polarity question
Post by: graphic66 on February 07, 2009, 05:32:34
It will most likely have a fried voltage regulator with the polarity reversed. It will still start and run like that. Switch it back and see if it's charging.
Title: Re: Battery polarity question
Post by: bpossel on February 07, 2009, 12:12:09
Mespe,

Reading your description below makes me think that the ground cable (-), connected to the body, is just "red" in color".  Color makes no difference, but typically negative is "black".

I would also guess that the battery in your car has the positive (+) terminal on the left side and negative (-) on the right side which makes the ground cable stretch & connect to the battery in a diagonal fashion. 

In summary, just make sure the cable connected to the chassis is connected to the negative (-) terminal on the battery.  The positive (+), longer cable, connects to the starter.

To make it easier in the future, next time you buy a battery, get one with the terminals reversed (neg=left; pos=right).

Bob  :)
Title: Re: Battery polarity question
Post by: mespe on February 07, 2009, 13:09:57
OK Cool Consensus is Neg ground, that's where I'll start. thanks for all the input. Can't wait to get started on her,,,