Lotus Elan

S2 / S3 no 12v on ACC side of ignition switch

PostPost by: gjz30075 » Fri Sep 20, 2019 12:39 am

I'm trying to find a good spot to connect my cigarette lighter for 12v to work in the accessory switch postion
(and 'on' position, obviously) but I have no 12v anywhere on the fuse box with the key in the accessory position.
My Sprint has the 12v in the upper left hand side (viewed from the front) when in ACC mode but I can't figure
out why my S3 (with S2 wiring) has nothing. With the key in the 'on' position, everything works as it should.

Without pulling the dash, I can see all spades are used on the ignition switch. The fuse box has a white wire
connected to the bottom left, and branches off with another white wire to the top left, per the S2 wiring
diagram.

It may be related to the fact that I gutted the tachometer and installed a modern air core type of movement, so
the tach's white wire is not connected to anything. Could this be the issue?
Greg Z
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PostPost by: steve lyle » Fri Sep 20, 2019 1:05 am

I'm looking at the S1 & S2 wiring diagram in the Workshop manual. It shows that in position 4 of the ignition switch there is a white wire connected that feeds both fuses in the fuse box. Position 4 should be accessory.

Position 2 is "run", which on later cars is the white circuit. So it's possible that your car has the white wire connected there, and possibly nothing connected to position 4. Or maybe a dedicated wire to the radio, if fitted.

The S3 diagram shows a White/Purple wire at position 4, which matches my Sprint wiring. It feeds one of the fuses in the box, and the diagram shows a Purple wire at the other end of the fuse.

If I were you, I'd get a multimeter, put the ignition on accessory, and check each wire coming out of the switch until I found one with voltage on it. Or, alternatively, check for continuity between Brown (which brings voltage to the switch) and each of the other wires at the switch, with the key in accessory.

I don't see any way your issue is related to your tachometer mod.
Steve Lyle
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PostPost by: gjz30075 » Fri Sep 20, 2019 9:22 am

Thanks Steve, and I agree, most likely the problem is not a 'missing' tach issue. I can't get to the backside
of the switch and I'm not really wanting to pull the dash yet. The Sprint is easy, in this regard, as the switch
simply 'pops' off the column.

There must be some power at the accessory side because my windows work with the switch there . They
don't work with the car switched off but also they do work in the 'on' position.

I guess I need someone with an S2 with their key in the accessory position to tell me where the 12v goes.
Fuse box? Maybe some mating block behind the dash? Or....
Greg Z
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PostPost by: types26/36 » Fri Sep 20, 2019 1:15 pm

gjz30075 wrote:I guess I need someone with an S2 with their key in the accessory position to tell me where the 12v goes.Fuse box? Maybe some mating block behind the dash? Or....

Greg, I doubt its of any help to you but I just checked my S2 and I also do not have any 12v at the fuse box with the ign switch in the accessory position.
Brian
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PostPost by: gjz30075 » Fri Sep 20, 2019 2:17 pm

Brian, that is helpful. I'm pretty sure I'm wired correctly (well, not me personally :-), as the S2 wiring
diagram has the cigar lighter picking up power from heater motor switch, but I was hoping to pick up switched
or accessory 12v from the fuse box. I currently have the cigar lighter going straight to the starter
solenoid (and fused) until I can pull the dash.
Greg Z
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PostPost by: types26/36 » Fri Sep 20, 2019 3:00 pm

Greg, Just a thought, by removing the astray and its backing housing would it be possible to get to the ign switch/wires through the hole?
Maybe loosening the dash mounting screws as well??
Probably not but I do seem to remember taking the ign switch on my S3 by removing the lower panel and first removing the wiper switch but my memory could be playing tricks :roll:
I know I have defiantly had the ign switch out on my S2 although it is in a slightly different place.
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PostPost by: gjz30075 » Fri Sep 20, 2019 4:48 pm

Brian, you're on the right track. I can see the wires and switch by removing the ashtray and I'm now
trying to figure out how to remove the wiper switch. With just the wiper switch out of the way, access
looks much easier. Pulling the dash back just a bit would help a lot. Thanks.
Greg Z
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