About the kindest things you can say about the Lucas wiring systems used on Jensen Healeys is that they are mysterious, challenging, interesting, puzzling, and less-than-perfect. The worst things have already been said by others along with other expletives, pleadings, begging, etc. Perhaps the information on this and the succeding pages will help somewhat.

Included in the “Wiring Diagram”section is a set of diagrams I made from the original wiring diagram that came with 15375. Even so, what is real and what is drawn are two different things entirely. The wiring diagrams trace each circuit from the battery through the various fuses, connections, junctions, instruments, lights and other components until it reaches ground. The diagrams are in word format and can be either opened directly or downloaded. I suggest you download them, although it is a little laborious. Then you will be able to customize them for your own electrical system as designed by Lucas, with a little help from the PO (if there was one).

In actuality, the fact that there are common wires, fuses, switches and connectors is a help. If you have EXCEL on your computer, you can go to the “Troubleshooting” section and download the troubleshooting spreadsheet, follow the instructions on it, and zero in on those components that are the likely cause of your electrical problems. You may still have to take out your handy voltmeter and disconnect some connectors to make the final diagnosis.

For those without EXCEL, I included a Word document that illustrates the power distribution. It can also help in a less detailed, and more visual way.

Finally, there is a “Under-Dash Photos” section with a series of photos of the under-dash components that might help you physically locate the offending wires, parts, connectors and gadgets. They are in Word, not picture format, because I needed to be able to label them properly. If you download the documents you will be able to make corrections, adjustments, notes. Also included here to help you with troubleshooting the connectors is a Guide to Plugs and Sockets. It shows the wires (by color) going to each of the (mostly under-dash) plugs and sockets.

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