Loss of power, 2002 Club car DS

[Dynamike]

Hello, I bought a 2000 DS at the end of the season last year, just now getting into riding it a lot. I noticed that after a few minutes of driving, it starts to lag in speed and power. (Still stays running though). I saw (what I think is a resistor, square box with two wires coming off of it attached to selenoid) and it’s burned. I’m new to golf cart repair however I’m not new to electrical repair. I read other posts about speed and thought it was the contacts in the V box until I found this resistor? I can’t find it anywhere online or in the electrical prints others posted on here.
Can’t seem to add a pic to show the “Resistor”.
My serial #A0020-889599
Correction. It’s a 2000