Silverspur

Has anyone ever converted early XJ (51J) electrics into the later type? I've got a late engine with 2-wire pick-up coil and a brushless 4-wire alternator in an early frame which is wired for a three cable pick-up coil and a brush type, 6-wire alternator. Anyone know which wires go where or is this a hopeless enterprise? Any help appreciated.

Thanks dt. I've just hurt my brain for the last four hours with the two wiring diagrams and it would appear that my main problem is that the FJ wiring is for the earlier type of alternator with brushes but the XJ engine is the later type without. It would appear that the solution to the problem is to replace the six-wire regulator/rectifier with the later four-wire jobbie and Bob ought to be your father's brother. The different pick-up coil wiring I may be able to solve by sucking and seeing, in that the third wire in the three-wire old model may well be just an earth, so I can easily remedy that. The two-wire new model appears to run the same through the harness on the JJ as the XJ, so I just have to get them the right way round (which isn't obvious); if they don't work one way, they should the other! Fingers crossed!

Thanks dt but I only have the XJ engine not the rest of the frame, so I have a mismatch of FJ harness and XJ engine wiring.

Hi, I'm new on here and I hope someone can help me. I've just installed a 51J Xj600 engine into an FJ600 frame, without mechanical difficulty. However, I've hit a couple of snags with the electrical system: a) The regulator/rectifier on the FJ frame is the finned, six wire type. The wiring from the XJ600 engine has only four cables, so I assume is the later 47X (I've learnt from posts on here!) regulator/rectifier. Can I marry the two? If so, what do I do with the spare brown and green leads in the FJ harness? b] The XJ engine has a two-pin plug carrying white-red-stripe and white-blue-stripe cables which would (from the wiring diagrsam) appear to come from the coil. The FJ frame has a three-pin connector on the ingnitor attached to the battery case with orange, grey and black cables. Am I right to connect the white-red-stripe cable, and the white-blue-stripe cables from the engine to the orange and grey terminals respectively on the igniter connector (and the black to earth?). If anyone can help me with this, I'd be very grateful. (Also if I ought to keep an eye open for other potential snags with this transplant...) Many thanks.