Lotus Elan and Lotus Elan Plus 2 Forums

Hi all. I'm trying to trace wiring, re: lotus-electrical-f38/alternator-issue-t33677.html

My S4 wiring diagram shows, at the ignition switch, the white wire from the ign light on position #2 with two other wires. My Federal '72 Sprint has that white wire on position #3, along with a small brown wire.

Where does this brown wire go?

I recently bought an ignition switch from Dave Bean and I moved wires over from the old switch, one by one, and I think all is well, as the car ran fine and alternator charged (for a short time) with the new switch. But, I could have missed something here (NOT unusual).

So, second question: Can someone with a Federal Sprint show me what wire goes where on the switch?

Thanks.

Greg, I copied these articles off here for reference:



I wired my switch this way, no reason for the federal to be any different than the rest of the world

Thanks Phil. My only difference is the brown wire is in a position to work the windows only with the key on. Been this way since I bought the car in '78.

I noticed the references show the brown wire in a position to work the windows with the key off (or anytime, really).

Do your windows work with the key off?

gjz30075 wrote:Thanks Phil. My only difference is the brown wire is in a position to work the windows only with the key on. Been this way since I bought the car in '78.

I noticed the references show the brown wire in a position to work the windows with the key off (or anytime, really).

Do your windows work with the key off?

Hmm can't remember... will check at the weekend.

So, what actually lights the ignition light with the key to the third position, ie, on, and the engine NOT running?

Is it grounded through the tach body?

Thanks,

no it grounds through the alternator

when the alternator is charging there is 12 volts on both sides of the light which means no volts no light

Thanks Gus. This is really frustrating. I'm trying to replicate the wiring (other thread) to simulate an ignition system. I thought I did, but couldn't get my simulated ignition light to light. Hmmm, I put the wiring back to
'stock' and now the real ignition light won't light. ARRGGHH.

I've got continuity throughout all the ignition wires. More checking needed now.......

gjz30075 wrote:Do your windows work with the key off?

My take on this, having been around the block a few times: on a convertible it is advantageous to be able to put the windows down, with the key out, in order to fit a tonneau cover when the rain starts- as it does in England.
To lift the windows, they key has to be in and turned on. I have had two DHC Elans wired like this but I'm damned if I can remember how the FHC is wired. (why would it be different?).

Pete, interesting. I don't know how or why the Federal cars are wired they way they are but depending on where I put the brown wire, the windows will work up and down with either the key on or key off. I don't have
the one way option.

Gus, I'm not sure how's its grounded.

Attached is a drawing of the ignition system as I see it. PLEASE correct me if I'm wrong.

The brown/yellow wire is to the base of the bulb. The white wire is to the case/side of the bulb.

Is it through the brown/yellow wire?

Gus really explained it well above.
It's not grounded in the conventional sense, except through the brown/yellow wire, via the alternator, with ignition on and engine not running.
As soon as you start, the alternator begins to charge and when its output voltage equals the input the light goes out.

Thanks guys. I'm slooooowly understanding this. I"m far from an electrical genius. I need you guys to
be at my house right now while I troubleshoot this

not quite right, the wire has to go from the fusebox then through the switch and on to the alternator. Now one of the fuses is switched so maybe what you have is correct.

Try this.

find the switched fuse, run a wire from it to a spare light bulb holder you happen to have in your drawer. from the other side of the light bulb holder, run a wire to the alternator,IG and L terminals. Connect to nothing else.

See what happens, report back

BTW I hate windows wired through the ignition switch. Annoying. Plus it beats up your ignition switch.

Well, I couldn't run Gus' test due to the alternator being bad. I took it to a big box auto retailer who tests these and it passed all the tests except the lamp test.

Previous to Gus' post, it was suggested to simply take the br/yl wire, with the key on, and ground it to chassis.
The light lights! I surmised then the alternator wasn't providing the ground.

I now wait a week for a new alternator and try again. I'll continue posting in other thread for alternator issues.
Thanks all!