Author Topic: Turn Signal Switch Clocking  (Read 883 times)

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Offline Bryan Boyle

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Turn Signal Switch Clocking
« on: Thursday,April 11, 2024, 07:46:04 AM »
I was having some issues with the turn signal cancelling using a replacement (by a (d)po along the way) cluster on the steering column.  Sometimes it would, especially in a hard turn, more often not...which meant, if I was not paying hard attention, being one of those proceeding down the road with the signal blinking until I noticed the arrow flashing in the binnacle.  Yeah.  Dumb. 

Ok, took off the steering wheel.  The pins to catch the cam were at 9 and 3..and the cam slots were horizontal.  Had to turn over hard to catch the mechanism.  Hmmm.

So, took out one of my spare (I'm using an aftermarket wheel, 1" narrower rim diameter) and compared (guess I should have done that when I swapped the wheel out.)  Pins on the OEM were at 12 and 6.  Hmmm again.  Could it be that the cancel cam was 90 degrees out? 

So, move the cam to have the slots vertical...activated the turn lever, twisted the cam till it clicked, turned back...stalk cancelled.  Did in other directions.  Same thing.

That meant that the pins on the replacement wheel to capture the slots in the cam were in the wrong position. 

Pulled the pins.  Measured the diameter.  Selected the number drill to match, and redrilled the replacement wheel so the pins were close enough to 12 and 6 on the hub.  Tapped the pins in, remounted.

Success.  Turn signals cancel when I turn the wheel back from left or right. 

Other thing was I didn't like the order which the center tell-tale lights in the binnacle were arranged; the left turn arrow was at the top (my crashpad is warped down on my side hiding the left arrow).  So...rearranged the lights, top to bottom: Brakes, Ignition, Beam, Left Arrow, Right Arrow.  Since I removed the PDWV, the Brake is only on when I have the handbrake pulled, so it's up top (and if I release without having the seat belt on, the light on the console squwaks), I can see the ignition/alternator light, and the beam light is visible...and now, both arrows are in my line of vision.

Love it when a plan comes together. 

Next up: installing the modified Tach with the conversion board (changing it to a compatible electronic module for the Pertronix ignition).  Since I rewired the brake light circuit to remove the DB10 (I installed euro taillights with separate turn and running/brake lights, it's not needed...the brake lights are fed directly from the switch), there is a free lead from the engine room (the green/purple wire normally between the brake light switch and terminal 5 on the DB10) to get the signal from the coil back up to the dash area.  That'll be this afternoon's project.
« Last Edit: Thursday,April 11, 2024, 07:57:04 AM by Bryan Boyle »
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline Bryan Boyle

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    • Lotus Europa Collection
Re: Turn Signal Switch Clocking
« Reply #1 on: Thursday,April 11, 2024, 10:23:37 AM »
Success!  Swapped over the converted tach from the RVI to the RVC conversion...used the spare lead from the brake switch to the DB10 relay...hooked power, ground, signal...hooked up battery...fired off just fine. 

(You do have to hook the 2 white wires on the back of the tach together; the coil gets its power through the white leads, so, unless you've provided 12V to the coil in another circuit, need to get the power back there.  Now that I think of it..that makes a great place to put a hidden ignition cut-off to add a layer of anti-theft to the whole thing...hmmmm....not that this car would not stand out if you reported it nicked...)

« Last Edit: Friday,April 12, 2024, 06:03:41 AM by Bryan Boyle »
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline FourLoti

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Re: Turn Signal Switch Clocking
« Reply #2 on: Thursday,April 11, 2024, 11:36:13 AM »
Nicely done, Bryan!

We must be on the same schedule. I recently had to switch from the original RVI tach to RVC. But not in the correct fashion as you did by having your original 8K tach converted. I happened to have a perfectly good identical (except 7K) unit left over from a prior project and, since my original tach was becoming mostly useless, I decided to swap them out and let the next owner restore the 8K at their leisure. (I'll try not to bury the needle in the meantime :)

This may be of interest to those who don't have that spare wire running fore-aft like you do. There's another "almost" spare wire already installed. At least on Federal cars with pressure diff brake switches in the rear. It was discussed recently, but there is a large #10 red/black wire running from the dash to that brake warning switch. Rather than try to fish a new wire through the interior and firewall, I simply commandeered this #10 guy for my tach purposes. (more interested in accurate rev counts than I am in having an idiot light tell me my brakes have gone wonky - while I'm experiencing the wonkyness in real time!)

Anyway, I left the wire in place and disconnect it from the switch. It comes into the engine bay only about a foot from the coil, so it was very simple, and reversible, to slap a #10 T-Tap on it and jumper it to the coil - see photo.

At the other end, it terminates next to the fuse block (other photo) and it was a simple matter of unplugging it from the idiot light/handbrake microswitch circuit and running another jumper to the tach. Works perfectly and, once again, easily reversible if desired.

Cheers,

Ron
« Last Edit: Thursday,April 11, 2024, 11:43:16 AM by FourLoti »
1974 TVR 2500M
1996 Porsche 993 Carrera Coupe
2005 Mitsubishi Montero Limited
1974 Europa Twin Cam Special 5-Speed (gone)
1987 Esprit Turbo (gone)
1980 Eclat (gone)
1963 Elan S1 (gone)
1970 Europa S2 (gone)

Offline Bryan Boyle

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Re: Turn Signal Switch Clocking
« Reply #3 on: Thursday,April 11, 2024, 01:37:45 PM »
Nicely done, Bryan!

We must be on the same schedule. I recently had to switch from the original RVI tach to RVC. But not in the correct fashion as you did by having your original 8K tach converted. I happened to have a perfectly good identical (except 7K) unit left over from a prior project and, since my original tach was becoming mostly useless, I decided to swap them out and let the next owner restore the 8K at their leisure. (I'll try not to bury the needle in the meantime :)

This may be of interest to those who don't have that spare wire running fore-aft like you do. There's another "almost" spare wire already installed. At least on Federal cars with pressure diff brake switches in the rear. It was discussed recently, but there is a large #10 red/black wire running from the dash to that brake warning switch. Rather than try to fish a new wire through the interior and firewall, I simply commandeered this #10 guy for my tach purposes. (more interested in accurate rev counts than I am in having an idiot light tell me my brakes have gone wonky - while I'm experiencing the wonkyness in real time!)

Anyway, I left the wire in place and disconnect it from the switch. It comes into the engine bay only about a foot from the coil, so it was very simple, and reversible, to slap a #10 T-Tap on it and jumper it to the coil - see photo.

At the other end, it terminates next to the fuse block (other photo) and it was a simple matter of unplugging it from the idiot light/handbrake microswitch circuit and running another jumper to the tach. Works perfectly and, once again, easily reversible if desired.

Cheers,

Ron

I couldn't find the other end of the wire from the PDWV inside the cockpit...guess I didn't look as far as you did...lol.  The wire from the (unused) db10 was right there near the tach; I did run a wire from the negative coil across the front of the engine room (nicely tied up and hidden by the vapor canister (which I have in place just because...doesn't do anything...) to the unused wire off the brake switch.

That gives me an extra lead someday.  Thanks for pointing out where it ends up!
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.

Offline Bryan Boyle

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  • Joined: Feb 2022
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  • 1974 Europa JPS #142 3291R
    • Lotus Europa Collection
Re: Turn Signal Switch Clocking
« Reply #4 on: Friday,April 12, 2024, 06:04:55 AM »
Update: Took her out in between rain showers...down the interstate.  Close enough: 60 MPH on the speedo, a tad over 3K on the tach.  About right (iirc, in 4th, it's 21 mph per thousand RPM(?))...well, won't ever get to redline with this engine...so, a needle over 3k @60 is about right as I recall.

On to the next disaster.
Bryan Boyle
Morrisville PA
Commercial Pilot/CFII/FAA Safety Team
Amateur Extra Class Operator & FCC Volunteer Examiner
Currently working on 3291R, ex 444R, 693R, 65/2163, 004R, 65/2678
http://www.lotuseuropa.us for mirror of lotus-europa.com manual site.