Late Federal (Fail-safe) Headlight Wiring

[pharriso]

Phil
Thanks for the diagram. I still can't work out why everything works on mine apart from the main beam warning light.
Unfortunately I got hold of a new UK front loom and joined it to my federal dash. I had to run a separate wire from the micro switches on the dash to the relay.
Everything works apart from the warning light
Anyone any ideas??
Thanks
Terry

Terry, your main beam actually works? If so it can only be three things:
1. You've lost the power feed from the dip switch (blue/Green wire) to the warning light
2. The bulb is blown
or 3. There is no earth to the bulb holder (black wire.)

By running an extra +12v & earth wire around you can quickly figure out which of the 3 conditions you have.

[pharriso]

Hello,

on the Fed Sprint a red/black wire were installed from Lotus, this wire was not in the wireing lom implemented, it was a typical "Lotus" solution...
I'll modify the headlamp wiring as you can see in the appendix. This modification has some advantage to the original solution:
1: The red/black wire is no more needed, so no extra bad looking/not protected wire in the engine bay
2: When you are flashing, the high current for the light's will not come from the dasboard switches and the small blue/yellow wire


If someone founds errors in the schematic please lett me know.
Thanks

Mario (Mariodschy), I can see your logic. Eliminating the Red/black wire & replacing the 3 terminal relay with another 4 terminal.

I can't remember if the red/black wire was bound in the loom or an added wire, I will check during the holidays...

I like that the high power does not go through the dash switch, but to be honest it's not a feature that I have used in the last 6 months!

[terryp]

Thanks Phil, I think it must be the blue / green wire
I do hope it's not the bulb .......... But no one will ever know!

Cheers
Terry

[mariodschy]

In the appendix you can see how it looks like in my car.
First i thought this was installed by an former owner because it looks so noobish, but now i am sure that this is the orignial solution done by Lotus. They use on ALL cars (FED an ROW) the same wireing loom so it was the easeast way to add this wire. For the deFederalising work i am pretty happy about this because it makes the change very easy.

[Rokkbert]

Hello,
Great wiring diagram, much better than the workshop manual.
Do you know if this would be applicable to a federal plus 2? Or if not, what would need to be changed?

[pharriso]

The only thing that is different here is the micro-switches added to the headlight switch & the elimination of the micro-switches from the headlight pods. So if you have the same set up then I do not know why not... I do not have access to a federal Plus 2 wiring diagram...

[stugilmour]

Hello,
Great wiring diagram, much better than the workshop manual.
Do you know if this would be applicable to a federal plus 2? Or if not, what would need to be changed?

I think my Federal Plus 2 was different. Perhaps Phil can clarify the "Light Rocker Switch - in Dash"? My car uses a two pole momentary flat rocker switch and a relay latching circuit for the side lamps. Phil, is the switch in your car a simple On/Off rocker or a momentary affair? Anyway, I posted a side light diagram here.

lotus-electrical-f38/side-lights-t17589.html

The Federal Plus 2 diagram for the lighting circuit is difficult to read as it is sort of a physical layout diagram combined with a schematic. When the microswitches moved to the dash. the diagram had a weird addendum added and I think they minimized changes to the loom.

When I rewired my car I recall rationalized the wiring a bit. I never bothered with a flashing relay, opting to install flash to pass using a modified Triumph column stalk running to some driving lamps. I don't recall that the stock wiring had the flashing circuit in it.

Stu

[pharriso]

I'm talking about the push/pull vacuum switch, not the sidelight rocker switch

[gus]

My Federal +2 had no flashing circuit, and I do not recall any of the early style[2 fuse]having such

[terryp]

Thanks Phil, I think it must be the blue / green wire
I do hope it's not the bulb .......... But no one will ever know!

Cheers
Terry

I fixed it!
It was a problem between the FED Dash loom and the UK Front loom and the fact that one was wired for the Flash option. I just changed the wire to the warning lamp and hey presto it worked!

Terry

[crypto]

Good drawing but may I add an important comment

As shown in the diagram, the micro switches (on the headlight vacuum switch) ARE necessary also on non failsafe cars (at least the top one). Why ? If dipped beam is on, i.e. current will flow via dipped beam relay W1/W2 down to the pod switch (lower right corner) on non failsafe cars. So far ok.

Operating the vacuum switch will make the pods to go down and to open the pod switch. Current flows now via dipped beam relay W1/W2 to main beam relay W2/W1 back to the dash high beam warning light and then to ground. Depending on the relay coil resistance(s) and warning light your dipped beam and high beam may be on with the pods down. Was the case on my car when I reworked all the electrics.

They will only turn off if you turn off the rocker light switch on the dash. Possible solutions are, a micro switch with the vacuum switch (as shown) or a diode in the supply line of the main beam relay, avoiding current flow via warning light.

Peter

[gjz30075]

Thanks Phil, appreciate it!