Convenient earth near dashboard..

[TonyA]

I am in the process of installing led lights: the electronic flasher units (one for hazards, another for indicators) require earths: recommendations appreciated for a convenient earth point or earth source around the dashboard area. Thx

Tony

[rgh0]

There are a set of black wires behind the dash earthing various instruments that go down to earth on the chassis at the bolt into the chassis on the lower right of the central dash panel section.

cheers
Rohan

[TonyA]

Rohan, thanks for such a fast reply: could you help me find this earth pont: I have removed the panel under the dash and the one in the footwell along the forward part of the transmission tunnel to get a good view of the wiring: what/ where do I need to look to find this magic earthing/mounting bolt..Maybe a photo will help..thx

[vstibbard]

The bolts into chassis for the lower dash bracket that the dash panel bolts to is where the earth lead to behind the dash.
Vaughan

[Lotusian]

As photo, on right immediately behind dashboard, bolt through bracket into chassis should have the black earth wire.
Ian

[TonyA]

Getting clearer ..thx. Do I need to lift up the padded panel that contains the gear lever to get at this earthing Eldorado..?

[gjz30075]

No, you just need to remove the lower dash valance for access.

[TonyA]

I have found the bolts: 1 1/2" x 3/8 UNF, big washers, Hurrah ! Many thanks. I have now been able to install electronic hazard and indicator relays, which each require a dedicated earth not needed on the old style mechanical types.

I might add for anyone interested that this was all to install LED indicator bulbs: turns out that on cars with the speedo indicator bulb across the right and left indicator feeds, four LED bulbs does not have enough resistance to prevent the current flowing across the speedo bulb so that while the indicators on one side flash, the other sides' glow continuously ! : the solutions are 1. Install resistors: they are hot and have to be carefully positioned in a plastic car and obviates the benefits of LEDs reduced load on the wiring or 2. wiring in diodes to prevent current back flow: this requires access to the speedo indicator bulb wires and a gynaecologists dexterity or pulling forward the dashboard and all that entails in terms of risking moving other connections or 3. use two LED bulbs and 2 conventional bulbs: enough resustance to avoid backflow, but still half the load on the wiring, and no messing behind the dashboard. I chose option 3. Electronic indicator relay clicks nice and loud,- very welcome given how faint the speedo indicator lamp is !

[TBG]

Gosh that sounds so complicated! I just changed all my bulbs to LED and fitted a compatible flasher unit. Simples!! D

[ericbushby]

Hi Tony,
I do not understand a lot of this.
I changed all lamps to LED, except Ignition and head lamps some time ago. All parts were supplied by Classic car LEDs of Cheltenham including three different fitting instrument lamps, bayonet, screw in and push fit types.
All parts are direct plug in replacements.
A compatible flasher unit was needed and there is a convenient earth point using the clamp nut on the back of the speedo.
It seems to me that you are fitting extra components, complications and wiring unnecessarily.
Maybe my S3 is a lot simpler than your car but at the moment I cannot see a reason for all your extra work.
Eric in Burnley
1967 S3SE DHC
PS. my speedo indicator light is brighter than before.

[Craven]

Eric,
I think he’s talking about a later flasher system that uses a 2 pin flasher unit, where the speedo light current flows through the inactivated side, because this current is very low it does not show up, but when LED’s are used this very low current does light the inactivated side.
FWIW.

[ericbushby]

Hi Craven,
OK, thanks for that. I have no need to look into it, but I still wonder if a system using a flasher unit with a separate output pin for the dashboard lamp would be easier. Perhaps I am not allowing for the hazard function.
I will not be buying a different Elan so I do not really need to know, just curious.
Eric in Burnley

[RichardS]

I fitted LED indicators, from Classic LED and the final result is excellent, nice and bright!
I also had to sort out a few issues, one of which was that the indicator switch was tracking which didn’t cause an issue with the old bulbs, but the LEDs were permanently on with the small current leakage across the switch.
I had the indicator switch refurbished and all sorted.
Richard

[TonyA]

The indicators flashing with the stalk in the mid position is a phenomenon I am experiencing with the electronic flasher ( from Classic Car Leds as it happens but widely available elsewhere too) . No such problem with the old style aluminium bodied mechanical type; I am told by the proprietor of Classic Car Leds that the electronic flashers are much more sensitive to small current leaks thru the indicator switch in mid position from dirt, corrosion in the switch mechanism contacts etc than the traditional flasher.. I will try and clean my contacts . Any advice on getting at and cleaning the indictator switch ( contacts) most welcone: mine is a 1971 UK spec S 130 , with alternator and 3 fuse boxes In the engine bay.. Can I just spray contact cleaner or is dissemble reqd...The Workshop Manual says getting at the indicator switch depends on wether the car has a collapsible steering column:or not how do I tell?

[mbell]

It will have the spitfire collapsible column. You need to:
1) Remove steering wheel
2) Remove the cowel over the column
3) Remove two screws holding the stalk into column
4) disconnect the wiring (think it might run through a column mount bracket.)

The switch is rivet together, so requires a bit to open.

I fitted a new switch to my car after experiencing smoke an none functioning indicators. There contact on to a printed circuit board and wears.