Hi
I'm helping my 82year old (83 next week) grandfather restore his 1977 XJ12.
We have several issues that we have not been able to work out so hoping someone can shed some light and help.
Problem 1
We are going through wiring and he has worked most of it out and got to work, we are at the moment working on the indicators- flashers. We have right side of car working both front and back, but the left side the back works but front as soon as you turn key the light is lighting up. We are perplexed as power is running to the light on ignition turn and it stays on. The rear light dosnt stay on but works perfectly how it should.
My grandfather says the two lines join and then is wired into the flasher unit. Issue is why front stay lit if back dosnt? I originally thought he got his green and blue mixed up (he's colour blind) but if the battery gets a bit flat it will flash when indicator turned on. I wonder if they don't join and he has wired the antennae power into the flasher?
I hope someone can shed some light. Lol
Look forward to your replies.

 

See if you can find a Haynes book with the wiring diagram. You can also find the Lucas wiring colour standard on the internet which tells you the purpose of each wire, (many have main and tracer colours).

Here is one pdf for the colours: -

http://www.autoelectricsupplies.co.u...ew_order_2.pdf

Sounds like you have a wire crossed somewhere. The indicator stalk switch on the steering wheel binnacle supplies volts to either left or right lamps, (plus the L/R dash panel "arrow" lamps"). These volts come to the switch from the flasher unit itself, and when current is drawn, this clicks and switches on/off at the correct interval until current draw stops. I am not sure of the Series 2 cars had a bulb failure module to complicate things.

 

Thank you for that. It's very helpful.
He has the repair manual for the car with the wiring diagram but the list helps.
We ended up finding that he correct wire was stuck in the body so plugged it in and it now works. Yippy one issue down a few more to follow
We are now working on the interior lights, we have found power running thru both wires to the light. If we put an external lead running to the car earth they work. I followed the purple cable back and it seems to then plug into the clock. I think we have to unplug and start again as it appears maybe he has wired incorrectly. Lots of fun.lol
Do you know where we can get a replacement hazard light switch? Is there an after market one?
Cheers

 

These dash panel switches were very peculiar to Jaguar, and not found on other cars. They are a Lucas product, and prone to failure, but can be dismantled and made to work, provided nothing is broken inside, (I have done this myself many years ago).

Doug Dwyer no doubt has better advice on these switches as with me it is a very long time ago.