Glow plug light on john deere 6330 comes on when roading. if roaded at lower rpm light does not come on.

SOURCE: Battery lite glows when pto is engaged after running for 5min

The charging circuits used on smaller tractors are generally barely adequate for the load presented to them, so it is important that the tractor engine is running fast enough especially when using PTO power. If your tractor has a tachometer on it, JD has an indication of the motor speed you should use when using the PTO. If not, it is generally pretty close to max. It should sound like it is running smoothly although fast, and not with whining or rough sounds from the engine.

SOURCE: Have John Deere 165 riding mower. Strong crank,

Has it been outside? May be water in the fuel.

SOURCE: John deere gx345 has no spark at plug what is the cause?

need new coil pack or have short in harness grounding engine from running. check fuel line to carburator. 1. take float bowel off bottom of carb. do not touch float or pin holding float. crank engine over until fuel comes out of carb. If fuel comes out, you don't have fuel problem. put float bowel back on carb. 2. check for spark. take spark plug out of mower. put wire back on plug and place the threads on head [or metal of engine to ground the plug]. crank engine over for a few seconds to see if plug gets spark . [always double check with another spark plug that is good]. [[ Remember!!! you have to have someone sitting on the lawnmower to start. unless you by-pass safety switch [only do this if you understand how the safety switch works. NOT EXPLAINED HERE!!!]] If spark is present, there is no grounding problem. when engine is cool. 3. CHECK COIL PACK. for continuity. When the coil pack gets hot it will stop any juice to the plug. A>Check temp sensor B> Check Safety switches grounding out. C> Check for cut wiring harnes. [loose wires rubbing against pulleys, wires cut by rodents]. Hope this helps.........................GAS