Series 1 main wiring

I have car #30148 and my horns are in the bonnet. Can’t help with the wires though. Still waiting on a new harness from RIW.

Rick OBrien
65 FHC in FL

I bought this car as an abused semi-wreck. As I have gone thru the car, many parts had been changed. Even the rear torsion bar was bent. The horns are in the bonnet as in robrien24 and we are 450 cars apart in #. I will look for wire colors but I’m on crutches right now from a bike accident.

Oops… I stand corrected Re horns in bonnet… change was in June 65 according to Haddock and Muller at chassis number #30856 for the LHD coupe… my bad should have checked first.
Danny

thanks I am saving that chart

The colors of the two wires are GREEN and Black w/Red stripe and they are heavy wires with round push connectors. They come out of the main harness just after the Brake pressure switch on the corner of the window, left side. Is there a ‘relay’ for the cooling fan? I am not aware of it.

Ok Daniel
Yes there should be a relay.
The green is power to the relay ( switches on with ignition)
Black/red is from the otter switch ( on the radiator header tank) and at the otter switch end there should be a black earth strap.
From the fan itself there should be a green/black to the relay … see photo of this part of circuit and a black earth strap

As the coolant reaches a specified temperature the circuit is completed and the black/red is earthed and trips the relay which then via the green/black will power the fan.

If you don’t have the Lucas relay you can substitute with a generic relay… if you need help with that let me know
Hope this helps ( ignore my penciled trinary switch modification it does not apply to your standard setup.)

Sorry. That is incorrect. There was no cooling fan relay on a '66 S1 - the early 3.8s had a relay, but Jaguar did away with it later. It returned for the S2s (and probably the S1.5s). The Green and Black/Red wires are the 2 wires for the cooling fan. You could add a relay if you want, and this is probably advisable if you are using an aftermarket fan that takes more current than the original.

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Ok so my experience with a early 4.2 and wiring diagram says different… I don’t have an issue either way… Jaguar-often changed things at a moments notice so it is always hard to be definitive about some of these things… I would still put relay on it… obviously Jaguar decided to put back on … so this meant they thought it was better.

Thanks but the only relay I am aware of is behind the splash guard of the left front tire and all those wires are part of the main wire harness and are separate from this subject. If these is another relay, I don’t know where it is or where it goes. The two wires I am trying to determine are just below the brake switch and well after the relay on the splash guard. I’ll have to look to see if I have another relay or look at someone’s car…

Dan

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Ok Daniel
Yes there should be a relay.
The green is power to the relay ( switches on with ignition)
Black/red is from the otter switch ( on the radiator header tank) and at the otter switch end there should be a black earth strap.
From the fan itself there should be a green/black to the relay … see photo of this part of circuit and a black earth strap

As the coolant reaches a specified temperature the circuit is completed and the black/red is earthed and trips the relay which then via the green/black will power the fan.

If you don’t have the Lucas relay you can substitute with a generic relay… if you need help with that let me know
Hope this helps ( ignore my penciled trinary switch modification it does not apply to your standard setup.)

Ok Dan … firstly the relay on the splashguard is usually the horn relay.

If your car hasn’t got a relay at the front … then as David says it may not ever have had one… in that case the wiring goes straight to the fan connections… assuming that the original fan is installed the green wire goes to the Green/Black on the fan and the black/Red goes to the black on the fan connection… to test that it works … take the Black/red at the header tank ( otter switch ) and short it to the earth ( frame on an area without paint…bolt head etc) and the fan should come on… providing that the ignition is on!.. the otter switch will not work if the coolant is not hot.

Hope this helps.
Cheers
Danny

I wasn’t aware that any 4.2 S1s had a cooling fan relay, so thanks for letting me know your early 4.2 has one. The wiring diagram in my Jaguar Workshop Manual for the 4.2 shows no relay. As you say, sometimes Jaguar changed things without documenting them, so we learn new things every day!

The relay was re-introduced when they changed to dual fans, so that was probably the motivation. That said, adding a relay if there isn’t one is probably a reasonable idea, and if you have upgraded to a higher current aftermarket fan is probably a necessity.

Very simple question here…Are there two wires that attach at the Otter Switch? One to the switch center and one to a ground lug on one under one of the screws? And these two wires are held by a clip/screw under the water tank?

Yes Daniel… one to ground will be black the other should be black/red ( the other end of the original pair of green and black/red… not sure about how they are held I place.
Cheers
Danny