Jaguar Repair: Engine Electrical, oil pressure gauge, ballast resistor

Question
QUESTION: I purchased a 1985 xj6 with a chevy motor. I replaced the engine and transmission with a 1975 4.2L carbureted engine. However, all if not most of the original 85 electrical harness was removed. I am in the process of wiring the 75 engine. All I have is the 8 pin connector on the passenger side fender well which was used to wire up the chevy motor. I have a repair manual from British Leyland, but there are no electrical schematics in it. Need to wire up the ignition coil,oil and temperature sending units etc. I am totally lost.I got the car started, but thru the ballast resistor, I have approx 7 volts so my spark is yellow. How can I get a color coded engine bay electrical schematic without having to spend another $103.00 for another manual.
Thanks, Frank

ANSWER: Hi Frank,

I have a factory electrical training manual and I will work you up a few diagrams that should help. I can't copy all of it as it is 50+ pages long but I should be able to sort out the engine compartment stuff. Give me a few days to work on it.

Howard

---------- FOLLOW-UP ----------

QUESTION: Thank you very much. After sending you my request, I used my trusted multimeter and came up with the following results on the existing 8-pin connector:
White/tan tracer = Oil Pressure Gauge
Black/brown tracer = Oil Warning Light
White = Coil+
White/Grey/Blue Spiral tracer = Coil - Tach
Brown/Black tracer = Alternator
Green/Blue Tracer = Coolant Temperature
White/Blue tracer = ?????
Green = ?????
Extra Wire Green /brown tracer = AC ??
If the above is correct, please confirm.
I have 2 resistors at coil bracket. Seems as if they should be jumpered. I have a voltage drop (7V) at the ballast resistor (engine cold) I was of the opinion that cold engine voltage thru the ballast resistor should be high and as the engine warms up the voltage should drop since less voltage is required on a hot engine to ignite fuel. Maybe I am wrong.

Answer
The white w/blue tracer is the low coolant warning light which comes from the low coolant switch in the lower front of the expansion tank and goes to the low coolant unit in the right fuse panel.

The green w/brown tracer wire is the AC compressor clutch.

There are many green wires in the car as they are usually fused power wires for accessories and instruments.

I think you have the rest correct.

I had to work on electrics on many cars in the dealerships and I found the best way was to connect what you know is right and then check what don't work. And trace only one circuit at a time. Let me know what don't work and I will post a diagram of that circuit on my web site for you to copy. I have diagrams of each individual circuit.

Some of the series III cars used a low voltage (6v) coil thus it needed a ballast resistor. But I never seen a second resistor used for anything unless someone put an aftermarket ignition system on the car and it may have required a drive resistor. ???? Jaguar didn't use two resistors.

Howard