Injector loom colours and batch firing, Pre HE?

Hi, I am going to remake the wiring loom and I want to duplicate the original colors as close as I can.

I was wondering though: is there a logic to the colors used?

I’m trying to find out which injectors fire together, do all wires carry a voltage? Does each contact on an injector receive a voltage or is one contact an earth?

I can’t apply any voltage at the moment because I have too much disconnected and the battery is disconnected, engine is out, starter, alternator, relays all out of the car at the moment!

Of course I could just find wire colours like the originals and just copy the loom systematically but I wanted to find out how the loom works and what the logic is to the colours?

Thanks, Malc

Malc,
Do you have copies of the XJ-S Repair Operations Manual (ROM) and the XJ-S S57 Electrical Guide? I found all the information that you are asking about (wire colors and schematics) and what I needed in those documents when I rebuilt/repaired the fuel injector harness in my wife’s 1990 XJ-S convertible (5.3L V12 w/ Marelli ignition). Our car is different than your pre-HE car in many ways but I suspect that the ROM and S57 for your model year are good places to start.

Paul

Hi Paul I don’t have either. Sounds like I better get hold of those! The factory Parts Catalogue is fantastic for organising parts and reassembly but doesn’t include any wiring references.

Haynes manual also useful but not as useful as what you are saying there.

Thanks. Malc.

Malc,
I purchased my green covered hard copies of both the ROM and S57 on eBay, both are original licensed Jaguar publications.

I have read on this list that digital versions (CDs, downloads) are available but you will have to find out from others about those.

Paul

Thanks Paul I’ll look for printed versions.

Best regards, Malc.

Amazingly I just won the repair operations manual on eBay for £12.95 so I should be ok now!

Hat off to you doing your own loom. I had a new one made in Melbourne for less than $400. Looks like the OEM but has modern materials.