positive earth
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From: Oxford, UK
Although the insulation on the original wiring is fairly decent and should have survived well in the Belgian climate, yours looks pretty rough to me (from what I can see in the photo). Given that and the fact that it seems to have been seriously messed around, it may be easier as well as safer to follow Glyn's advice and replace the under hood harness in its entirety. If you do, work in a systematic way, putting in the new cables as you take out the old. That goes a thousand times over, if you try to re-wire the rest of the car (which I would generally discourage) where it's essential to use the old cables to pull tails to, in turn, pull the new harness through the sills and door posts.
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I suggest
1/make sure the wires to the coil are not touching any earth.
2/turn the ignition to on.
3/using your multimeter check that one wire has 12 volts. That should be connected to the sw or + terminal of the coil.
4/once you have determined this you can turn the ignition to off.
4/using your multimeter set to the ohms (resistance measuring) connect to the other wire and rotate the engine using the push button on the solenoid. That should give you a pulsing effect of going from short circuit to open circuit if the points are working OK.
5/that wire can now be connected to the CB or - terminal of the coil.
cheers
1/make sure the wires to the coil are not touching any earth.
2/turn the ignition to on.
3/using your multimeter check that one wire has 12 volts. That should be connected to the sw or + terminal of the coil.
4/once you have determined this you can turn the ignition to off.
4/using your multimeter set to the ohms (resistance measuring) connect to the other wire and rotate the engine using the push button on the solenoid. That should give you a pulsing effect of going from short circuit to open circuit if the points are working OK.
5/that wire can now be connected to the CB or - terminal of the coil.
cheers
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Junior Member
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Although the insulation on the original wiring is fairly decent and should have survived well in the Belgian climate, yours looks pretty rough to me (from what I can see in the photo). Given that and the fact that it seems to have been seriously messed around, it may be easier as well as safer to follow Glyn's advice and replace the under hood harness in its entirety. If you do, work in a systematic way, putting in the new cables as you take out the old. That goes a thousand times over, if you try to re-wire the rest of the car (which I would generally discourage) where it's essential to use the old cables to pull tails to, in turn, pull the new harness through the sills and door posts.
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Listen to Bill's wise advice and do that first.
But I want to get back to the subject of harnesses. I replaced EVERY harness on my car right down to the interior lights. The insulation was in poor condition especially the plastic covered wiring from the heat of the African sun ~ under hood/bonnet replacement is a no brainer.
A friend did a beautiful restoration on his Mk2 only to lose the whole car to a fire caused by the electrics because he went cheap and left the old & rotten harnesses in place. The entire Mk2 wiring is only protected by 2 fuses. The car was hopelessly under insured vs. it's true value & he got paid out a pittance for all that hard work, by his insurers.
Then there is the matter of fuse values to consider.
Warning ~ Fuse values
Remember that Lucas fuse values of 35 & 50 amp etc are old British 1 second blow standard.
Fuses you buy today unless you order specially are American Carry Current rating.
In modern fuse values you should select a fuse of approx half the value of the Lucas rating shown in Jaguar Manuals on our era of cars.
e.g. Lucas Horn fuse on an S Type = 50 Amps. In modern US rated glass fuses you should fit 25 to 30 amp max.
Failure to do this could cause a fire in our car's wiring in case of a short.
But I want to get back to the subject of harnesses. I replaced EVERY harness on my car right down to the interior lights. The insulation was in poor condition especially the plastic covered wiring from the heat of the African sun ~ under hood/bonnet replacement is a no brainer.
A friend did a beautiful restoration on his Mk2 only to lose the whole car to a fire caused by the electrics because he went cheap and left the old & rotten harnesses in place. The entire Mk2 wiring is only protected by 2 fuses. The car was hopelessly under insured vs. it's true value & he got paid out a pittance for all that hard work, by his insurers.
Then there is the matter of fuse values to consider.
Warning ~ Fuse values
Remember that Lucas fuse values of 35 & 50 amp etc are old British 1 second blow standard.
Fuses you buy today unless you order specially are American Carry Current rating.
In modern fuse values you should select a fuse of approx half the value of the Lucas rating shown in Jaguar Manuals on our era of cars.
e.g. Lucas Horn fuse on an S Type = 50 Amps. In modern US rated glass fuses you should fit 25 to 30 amp max.
Failure to do this could cause a fire in our car's wiring in case of a short.
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From: Llandudno, Cape Town, South Africa
Dust is indeed an issue. Small world ~ Aunt in PE.
The S Type is far better fuse protected than a Mk2/Daimler. My under bonnet/hood old technology plastic insulation had leached most of it's plastisiser and would crack if you bent a wire too far. Surprisingly the fabric insulation had fared better. While Belgium is cool by comparison (spent a lot of time at our European Technology Centre in Ghent), under bonnet is not thus the suggestion from both Peter & I that you replace just those harnesses/wiring. (and from your pic they look a bit of a mess)
The S Type is far better fuse protected than a Mk2/Daimler. My under bonnet/hood old technology plastic insulation had leached most of it's plastisiser and would crack if you bent a wire too far. Surprisingly the fabric insulation had fared better. While Belgium is cool by comparison (spent a lot of time at our European Technology Centre in Ghent), under bonnet is not thus the suggestion from both Peter & I that you replace just those harnesses/wiring. (and from your pic they look a bit of a mess)
Last edited by Glyn M Ruck; Jun 20, 2023 at 01:25 PM.
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From: Lake Cowichan BC Canada
Thanks bill,,, done the above and do indeed have a spark and on startup it sounds like the firing order is off,,,subdued backfire on at least one cylinder,,, followed the correct firing order 1L 4R 2R2L 3R3L4L1R,,, I presume 1 being at the front of the engine ie radiator not flywheel side?
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From: Llandudno, Cape Town, South Africa
Check where the Daimler No 1 is. On a Jaguar XK engine No 1 is the rear cylinder at the scuttle/firewall i.e. flywheel end.
Have you done a compression or leak down test? You might have a burnt valve. Some Turner V8's gave valve trouble. Remember to do at WOT (wise open throttle). The nonsense you hear about short bearing life is rubbish with modern lubricants.
Lovely smooth easy revving engine.
Have you done a compression or leak down test? You might have a burnt valve. Some Turner V8's gave valve trouble. Remember to do at WOT (wise open throttle). The nonsense you hear about short bearing life is rubbish with modern lubricants.
Lovely smooth easy revving engine.
Last edited by Glyn M Ruck; Jun 20, 2023 at 06:19 PM.
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From: Joyner, Queensland, Australia
If someone has been playing around with the ignition system, it could be any number of things.
I once encountered a 6-cylinder Land Rover where the plug leads were put in the opposite direction to the distributor rotation.
I have seen plug leads crossed onto wrong cylinders etc.
Go back to basics.
Check the direction of the distributor rotation. (This is important)
Rotate the engine until it is on top dead centre on the compression stroke on no 1 left cylinder.
Check that the rotor arm is pointing is pointing to the corresponding plug lead for 1L on the distributor cap.
Then make sure the other plug leads are connected in accordance with the firing order paying attention to the direction of distributor rotation.
By the way if that carby overflow/breather pipe is still leaking it means that the carby will be flooding and I urge you to get that sorted out.
I once encountered a 6-cylinder Land Rover where the plug leads were put in the opposite direction to the distributor rotation.
I have seen plug leads crossed onto wrong cylinders etc.
Go back to basics.
Check the direction of the distributor rotation. (This is important)
Rotate the engine until it is on top dead centre on the compression stroke on no 1 left cylinder.
Check that the rotor arm is pointing is pointing to the corresponding plug lead for 1L on the distributor cap.
Then make sure the other plug leads are connected in accordance with the firing order paying attention to the direction of distributor rotation.
By the way if that carby overflow/breather pipe is still leaking it means that the carby will be flooding and I urge you to get that sorted out.
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