The 'E' Type Forum

... which of the smaller lights should lit on when I turn the ignition switch ?

- choke light: yes if choke pulled
- map light: yes if door open or switched on
- heated rear screen: yes if manually switched on.

Now:

-inside the speedo: all 3 ?

The only single one which lights is the fuel tank sender one. Tank is empty, and when I pull one of the two outer wires on the tank sender it goes of.

What about the other two ? I found about 1-2 Volts on them. Its not missing ground. For example the white-blue does nothing...

Carsten

The igniton light should be on until the car is started
The blue one if the light is switched on and you turn on the switch for dipped? light

Ah, of course, the blue one is the long range control lamp. Will check.

But why does the ignition on- lamp not work ? Fuel control of course works on its own, when tank sees fuel it'll switch itself of.

But how is the ignition light controlled ? Direct parallel - to -coil wire to lamp ?

Carsten

On my S2, the ignition warning (red) light is controlled by the 3AW relay near the battery.

There are 3 cables to/from the 3AW relay -
a) An input from direct from the alternator, when the alternator is running this carries an alternating current and I measured about 9V at a fast idle
b) A cable direct the warning lamp
c) A cable to the body/ground/earth.

Hence the relay makes the lamp light if it doesn't see the AC supply from the alternator.

(My relay didnt work so I replaced it with a solid state solution, written up in the Upgrades section, but original relays are available online.)

Yes. The ign light should light. Just for those peering who have early cars the head beam pilot on early 3.8 cars is maroon colour. Not quite red like the ign light which is why I describe it as maroon. Not sure when it changed to blue. Anyone know?

Carsten : your car was I think 1966 ? If so , your" ignition" warning light may well be powered by the oil pressure switch on the right side of the engine near the oil filter !! This is not the big sender unit, but a smaller unit similar to the water temperature sender

Hi Chris,

Yes, 1966 it is.

I only found one looong wire with a 90deg spade connector on its end.

The sender unit sits on top of the oil filter assembly, and has a twin-spade connector on top (not dissected, just 2 spades for one signal).

No other wires present, except the pair for the tacho unit and of course the DR3 wiper motor.

I'll check that trace as well....

Carsten

If it had the oil pressure switch, the unit would be screwed into the oil gallery forward of the filter and just to the rear of the front RH engine mounting bracket

Ignore the fact that mine is a later block . If your loom had a wire for this , it would be either brown/black , or ( just possibly ) white

This is my setup: as found in the car for sure:



Carsten

Regarding electrics: I have found the 3 AW Relais next to the TR regulator, near the battery, firewall-mounted below the fan motor. 3 wires, of unknown color but very faded, and the 3 spades plus the cable plugs are all oxidized, so I'll repair this first.

My oil pressure wire is white brown, as can be seen above, near the connector on the switch.

The dip light switch is a bit strange - there is a part of the braided loom coming to it, 4 wires leave the loom, but only three are connected, the fourth is loose- but the only one to have 12 Volts on it.

The switch only has 3 connectors .... And it switches one pin in the 8-pin plug, from 2.9 to 3.6 Volts.

Carsten

Just to sum it up- this car has NO oil pressure switch, it has just a gauge. Maybe I retro-fit one, I found that XJ6 S3 had them, about 8 Euros. But they are notoriously instable, lots of forums say. My car only has the much more expensive gauge and sender setup.

The ignition light is only driven by the 3AW unit here, so I fixed it.

Main problem was missing supply to the centre tip of the ignition light bulb holder, the white wire was dead. After a lot of searching I cut it of and installed a new one. This now works a treat.

Carsten