With more than 650 matching parts, this is the overview for the John Deere 6630 from the 6030/6030PR series, covering trailer couplings, lighting and electrics.
A John Deere 6630 that runs hot, or heads out at dusk with half its lights working, costs you time. For both problems this page has thermostats, headlights, work lamps and micro relays, as part of more than 650 parts for this tractor from the 6030 series.
If the gauge creeps up under heavy load, or the engine barely warms up at all, the thermostat is the first suspect. Replace it together with the housing gasket or seal, then top up the coolant slowly with the engine idling and the heater open, so no air stays trapped in the system. Gaskets are available for other points on the 6630 too, including the exhaust gas recirculation valve, and there are O-rings for the oil pump among others.
When a whole group of lamps goes out at once, check the relay before the lamps. A micro relay swaps in seconds, and with a new one in your hand you know straight away if that was the fault. If the relay is fine, follow the wire to the lamp and look for a plug that has gone green with corrosion. Work lamps on the cab roof take a lot of rain and vibration, and that is where connections fail first. The headlights for left and right have dipped and main beam, and the work lamps include oval spotlights. A sensor for engine oil pressure belongs to the electrical parts on this page as well.
The brands behind these parts are GRANIT, Sauermann, HELLA, Scharmüller and MAHLE. Every part is new and comes from these manufacturers, nothing used or reconditioned.
The data plate confirms that you have a 6630 in front of you. After that, the reference number on the old part is the safest comparison, especially with thermostats and sensors, which often look identical from the outside. The other models in the 6030 series each have a page of their own: John Deere 6230, John Deere 6430, John Deere 6830, John Deere 6930, John Deere 6130 and John Deere 6530. The 6534 is part of the series too. For everything from the brand, see John Deere parts.