Interior lights and horn

[gannycat]

Hello Fellow Members,


I wonder whether you can tell me where to start looking for the probable answer. Rear interior lights have never worked for years. Front interior have now given up. No response in respect of the horn.


I have taken the following action: replaced all four fuses with 30amp and internal bulbs; result still no lights.
Could it be that the mice and nibbled the wiring somewhere?

Your valued comments would be very much appreciated.    (3 litre mk 1 1959)


Regards
Tony

[Simon H]

Put the original fuse back in. Chances are the problem(s) is/are dodgy bullet connector joints somewhere in the wiring harness. They tend to build up a layer of crud (oxidation?) between the inner and outer parts of the connectors after a few years. 56 years is pushing it a bit...

[gannycat]

Thank you all for your helpful comments.


Tony

[Oscar]

You will find some very poor photos of wiring diagrams here which may help you. I will make better ones some time.
Oscar

[djm16]

In my manual, the Mk 1 has a horn relay. It sits inside the R front inner wing opposite the dynamo. The middle lead is the live feed, the forwards lead is the connection to the horns and the rear lead goes to the horn ring on the steering wheel.

I would check the function of the horns first by removing the horn connection from the relay and instead connecting it briefly with a length of wire to the B terminal on the voltage regulator.

Until you know that the horns themselves work when connected directly there is little point going further.

Next would be to check that you have a live feed to the relay middle terminal. Remove the middle lead from the relay and connect that instead directly to the horn connection.

Live feed good? Then try reconnecting those two leads and grounding the rear connection on the relay to make the relay click ( and hopefully the horns sound too).

[Phil Nottingham]

Earlier P5's used the big very loud Lucas windtone horns which drew a lot more current than the compact lightweight modern type. These were also cheaper and the relay was not so essential but still handy to cut down volt drop