The 'E' Type Forum

Hi, I have been suffering from a few electrical issues that sort of came all at once. The two main ones were first the horn stopped working and on checking the fuses fuse 2 (50A) was blown. Discovered the horn relay packed up, ordered a new one from SNGB (not cheap) installed replaced the fuse all good.

Then the fan and brake lights stopped working obviously I turned straight to fuse 6 and that was fine. all other functions connected to that fuse work fine except those two issues which I can't understand. I sort of figured from the diagram that those two come off the same lug of the fuse and that is the only obvious connection between those two things which are at different ends of the car. There is no positive supply the the fan switch, and when I feed it a positive the fan will come on.

I will be eternally grateful to any of you experienced with the electrics (S1) and able help in shedding some light on this most annoying fault.

Suspect the fuse box assembly - they deteriorate over time and warp; 60 year old Bakelite is not stable. They are about £15 each (you will need two C16053) from SNGB so replace them as a starting point. They will eventually cause trouble even if it is not the gremlin problem now.

Hi David,thanks for replying. All fuse assembles are brand new from restoration and in any case when 12V is fed to the lug connectors the fault still exists.

Hi,
If you are happy with the fuses, then treat them as two different issues to start with.
Brake lights - have you tested the switch on the picture frame? Turn ignition on and put a jumper wire across the two terminals. If lights come on, likely to be the switch.
Fan - have you tested the both the temp switch and the relay? They work together to operate the fan.

Hi Richard, as stated the fan circuit works ok providing 12V is present on the variable thermostat, which feeds the relay, still can't find the brake light switch, remember this is a 1962 series1 3.8L that has been restored. If anyone knows where the brake light switch is on this model please let me know. Thanks for the reply.

Danny....front frame.....look through the S1 3.8 factory fit section..lots of original detail and photos...Steve

Brake light Switch shown below the fan relay.

Thank you all, will try and attack tomorrow.

Those switches are notoriously unreliable so suggest you consider the simple mechanical switch upgrade as a matter of course: viewtopic.php?f=9&t=3134

Go slow, since your early car should have the BRAKE LIGHT SWITCH up front near the RADIATOR AND your HORN connection is right there as well as your FAN CONNECTION.
Look for water from hose making the connections wet or GROUND wires wet or cut......
Take a test light and touch each connector with the key on .
Once you isolate each section it will come together fast.
Blown fuse is HARD SHORT .
I agree with others that the NEW FUSE BLOCKS are not the greatest quality, but since everything from that corner of the frame holds all the above, its going to be ground issue or you pulled the wires all in that corner some how.
Goodluck!
Grounds, connectors, GROUNDS!
You will get it!
GTJOEY1314
double ps, jumpthe wiresto the presure brake switch ,I went electric centuries ago.
I went hayden relay for thermostat centuries ago.....the quality of repro parts are beyond terrible.

Thanks Joey, I located the brake switch but didn't have time today as I needed to replace the leaking fuel pressure regulator, which arrived today, on my Cobra.

OK, found the broken connection and fixed it now have fan and brake lights, wasn't two separate faults was the main supply to both from fuse 6. Thanks for everyone's help.

All gremlins exterminated. The wires to the horns under the car were in a mess, tidied up and insulated, relay reconnected dual tone all fine no blowing fuse. The fan and brake light fixed and the reverse light briefly stopped working but was only a loose connection on the terminal of the fuse 7.

I took this opportunity to fit an electronic 10V regulator I have built and now my fuel and temp gauges are reading more accurately. The problem with the mechanical regulator is with the relatively high voltage the alternator is outputting it was always higher than 10V, in fact closer to 11.5V.