prusa i3 heatbed problem

i just completed the build on a folger tech prusa i3 after some hicups thanks to there spoty directions its up and running. My problem is the heat bed runs continuosly when the fan is on and vice versa if i turn the heatbed on the fan runs. I think i have a problem in the ramps board the heatbed is connected to the far left on the blue connector the fan in the middle. is that the corect layout? the fan conection part is missing from folger techs manual

Hi, welcome to the forum! Congrats on getting your printer up and running

The connections for ramps are shown on this link

The heatbed is usually connected to the connectors marked D8. What does you fan blow on? If it's for cooling the heatbreak/extruder then it's usually connected directly to the supply so that it runs all the time. Controlled fans are for cooling the recently printed filament to help control the build up of heat in the print. (Although... you can connect the extruder fan to the ramps so that it automatically switches on/off according to the hot end temperature. You might need some extra mosfets if you decide to do that though - the 3 on the ramps get used up pretty fast.)

its the fan on the extruder ill run it direct off the power supply so it stays on that's easier lol the heat bed is on d8 extruder hot head on d10 the odd thing when the fan was connected to d9 if I turn d9 on then d8 switches on at the same time is this normal since d9 is typically for a dual extruder so that both would run at the same temp?

No, I would expect d9 and d8 to be independent. Sounds like there may be a short on the ramps board that's causing them to be connected. Check that the cooling tabs on the mosfets aren't touching. The tab is connected to one of the pins (I can't remember which one), so each tab has to be electrically isolated from the other (always annoying if you just want to slap a few on a heatsink). If it's not the tabs you'll need to look for blob of solder or something similar that crosses two tracks on the pcb.