Lotus Elan

Mysterious switch...

PostPost by: tjb0274 » Sun Jun 09, 2019 9:35 am

Had a good forage behind the dashboard of my "bitsa" S4 today, tracking down some electrical gremlins as I get it ready for registration.

One surprise was a momentary-action toggle switch that was hanging free, but tucked up into the loom so that it didn't hang below the dash. It's at the end of two blue/purple wires that I haven't yet traced, but I was wondering if anyone has thoughts on what it could be for... It doesn't seem to do anything as far as I can tell, and the only momentary-action switches I can think of on an S4 are the window switches. which need to have two "on" positions, not just one.
1969 S4
1969 Europa S2
1990/1970 Ricciardi/Alfa
tjb0274
Second Gear
Second Gear
 
Posts: 59
Joined: 09 May 2018
Location: Australia

PostPost by: gjz30075 » Sun Jun 09, 2019 9:39 am

The other one, at least the one I have on my Federal Sprint, is the 'brake' warning light test switch. It's a black
plastic, push button type that got mounted in the under dash valance.
Greg Z
45/0243K Sprint
36/5727 pre airflow coupe
User avatar
gjz30075
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2828
Joined: 12 Sep 2003
Location: Roswell, Georgia, USA

PostPost by: types26/36 » Sun Jun 09, 2019 9:56 am

It has not got an electric fuel pump as well as the mechanical one has it ? sometimes people fit them just to prime the carbs after standing a while.
.......or even an electric antenna ?
Brian
64 S2 Roadster
72 Sprint FHC
User avatar
types26/36
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 3634
Joined: 11 Sep 2003
Location: U.K.

PostPost by: chickenstock10k » Sun Jun 09, 2019 2:07 pm

I have a similar switch in my plus 2. When I push it, it lights up the brake failure light on the dash. I could never really figure out what it was for though. Was it really intended just to test that the brake light works?
chickenstock10k
Second Gear
Second Gear
 
Posts: 60
Joined: 02 Dec 2018
Location: East Coast, USA

PostPost by: stugilmour » Sun Jun 09, 2019 3:24 pm

chickenstock10k wrote:I have a similar switch in my plus 2. When I push it, it lights up the brake failure light on the dash. I could never really figure out what it was for though. Was it really intended just to test that the brake light works?


I think that was the case. I expect the Federal regulations required a way to test the warming light, and this was the easiest way to meet the regs without adding a relay that would light up the fail light prior to the engine starting or some such.

Does your S4 have the dual brake circuit? The warning light we have in the Federal Plus 2 is triggered by failure of one side of the duel brakes.

Stu
Stu
1969 Plus 2 Federal LHD
2000 Esprit V8 TT
User avatar
stugilmour
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1701
Joined: 03 Sep 2007
Location: Calgary Alberta Canada

PostPost by: gjz30075 » Sun Jun 09, 2019 4:51 pm

Dual circuit in the Sprint. The light is wired to the cap of the Sovy can. The float in the can would drop
with a drop in fluid, from either circuit, triggering the light.
Greg Z
45/0243K Sprint
36/5727 pre airflow coupe
User avatar
gjz30075
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 2828
Joined: 12 Sep 2003
Location: Roswell, Georgia, USA

PostPost by: tjb0274 » Mon Jun 10, 2019 10:55 pm

Thanks for all the suggestions and thoughts :-)

Found out what it is yesterday - there was a bad connection and when that was fixed the mysterious switch turned out to be for the wipers - someone's idea for a driver-controlled intermittent, I guess.

The dash looks pretty new, so guessing the switch was mounted in a previous dash and then just left hanging when the dash was replaced :roll:

One of a number of things I'm sorting out with the wiring.
1969 S4
1969 Europa S2
1990/1970 Ricciardi/Alfa
tjb0274
Second Gear
Second Gear
 
Posts: 59
Joined: 09 May 2018
Location: Australia

PostPost by: The Veg » Sun Jun 16, 2019 3:56 am

stugilmour wrote:I think that was the case. I expect the Federal regulations required a way to test the warming light, and this was the easiest way to meet the regs without adding a relay that would light up the fail light prior to the engine starting or some such.


I think that is correct. I once had a '73 Super Beetle in which I recall something similar.
1969/70 Elan Plus 2 (not S) 50/2036
"It just wouldn't be a complete day if I didn't forget something!" -Me
User avatar
The Veg
Coveted Fifth Gear
Coveted Fifth Gear
 
Posts: 1296
Joined: 16 Nov 2015
Location: Atlanta 'burbs (southeast USA)

Total Online:

Users browsing this forum: ianf and 6 guests