Mahindra 5010 cab need heavy duty alternator

[Xfaxman]

Remove the battery ground cable at the frame and wire brush both contact surfaces. Remove it at the battery and clean there also.

Check the positive cable also.

 

[YanmarFever]

Thanks Faxman, but you could eat off the engine on my tractors, the posts are all cleaned and sprayed with battery cleaner.
BUT ! I will still check them, you can never be to careful....

 

[Bavarian]

If the engine rpm is varying with a changing electrical load it is because it is making more electricity.
The generating load is what is causing the engine rpm to fluctuate.
A larger alternator is liable to make it even more noticeable.
A larger capacity battery and heavier wiring from the battery to the load will be more likely to reduce the surging or just increase the engine rpm a bit.

Double that.