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voltage stabiliser S3?

PostPosted: Sun Oct 21, 2018 7:40 pm
by sepans
Cannot find a voltage stabiliser on my S3 not on either speedo or rev counter. I am converting from dynamo to alternator, positive to negative earth. Should I have one ? Do I need one with a alternator?
Cheers sepans (Brian)

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 7:30 am
by alan.barker
Yes,
you need one the Instruments are 10Volt supply. Follow the cable from Fuel Gauge supply to Voltage Stabiliser :wink:
Alan

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 10:45 am
by Craven
Sorry Alan!
S3 uses a ?fast? fuel gauge that is independent of both supply voltage and polarity (may need to swop terminals)
No voltage stabiliser needed. Rev counter is polarity dependent but has its own internal voltage regulator. So you will need to either modify your existing or obtain a later model.

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 10:48 am
by types26/36
I have never seen a stabiliser on a S3 and I have owned one and worked on four or five, the ones I have seen seem to have a wiring system the same as S1/2 cars but with the addition of electric windows.
All of the S1/2/3 cars I have seen have the earlier type fuel gauge that does not require a stabiliser.
As I recall the workshop manual does have an S3 wiring diagram which has the electric windows in but it is best used in conjunction with the S1/2 manual which is a lot simpler.

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 11:26 am
by ericbushby
Well, there you go.
Whilst agreeing with Alan above, I have found this.
My S3 had a Stabiliser when I bought it and it had been off the road for 25 years
My S3 wiring diagram shows four wires on the fuel gauge:-
A black which is the earth for the instrument lamp.
A red/white which is the feed to the lamp.
A green/black which goes to the tank sender.
A green which is the 10 volt supply from the voltage stabiliser.
The stabiliser is shown mounted on the tachometer, so it should be a short wire.
The stabiliser could of course be anywhere provided it has its correct connections.
If you can switch the ignition on, check the voltage on the input to the gauge. watch it for a while as it may be a steady 10 volts, or if original type, it will switch from 12 volts to zero alternately.
And whether you should have one or not, I do not know. If it works and is steady maybe it`s OK.
The diagram does not have a date, but the drawing number is LSL 145
Hope this helps
Eric in Burnley
1967 S3SE DHC

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 11:46 am
by alan.barker
types26/36 wrote:I have never seen a stabiliser on a S3 and I have owned one and worked on four or five, the ones I have seen seem to have a wiring system the same as S1/2 cars but with the addition of electric windows.
All of the S1/2/3 cars I have seen have the earlier type fuel gauge that does not require a stabiliser.
As I recall the workshop manual does have an S3 wiring diagram which has the electric windows in but it is best used in conjunction with the S1/2 manual which is a lot simpler.


May i suggest you look at the Wiring Dia "LSL 145 Lotus Elan S3" section "M" Electrical Section Workshop Manuel.
A Voltage Stabiliser is clearly shown attached to back of Tacho 3 wires Green x3 marked "volts stab".

I agree for Series 1 and 2 there is not a Voltage Stabiliser shown.
Alan

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 12:00 pm
by types26/36
Yes I agree it is shown in the S3 wiring diagram but the point I am making is I have never seen an S3 wired as per this diagram (except for the electric windows) and as Craven says the ones I have seen do not require a stabilizer being the early gauge and requires the early matched tank sender. (as per S1/2)
The early sender was unavailable for many years but I believe is now being remanufactured.
The wiring harness has been commented prevously.
lotus-electrical-f38/lamp-wiring-t31696.html

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 12:16 pm
by alan.barker
o.k. so the first thing to do is identify what Sender has been fitted and if the Gauge is 10v or 12v.
Alan

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 12:22 pm
by Craven
I suggests Sepans checks the type of fuel gauge type fitted to his car, a ?fast? gauge is a moving iron type gauge and is NOT voltage dependent. Oil & temperature gauge is a mechanical device and has no electrical connection. WHY would a voltage stabilizer be fitted?
I fitted an electronic voltage regulator to my S3 because, as noted, my tank unit was U/S and I had to changed the whole system over to later tank unit and a Thermal type gauge that is voltage sensitive.

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 12:51 pm
by types26/36
This is the early gauge and requires no stabiliser

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 12:55 pm
by alan.barker
What's the difference between regulator and Stabiliser.
I thought it was Stabiliser for the Fuel Gauge.
On my Sprint i have a Voltage Stabiliser for the Fuel Gauge and a Voltage Regulator for the Generator.
Alan

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 2:15 pm
by pereirac
alan.barker wrote:What's the difference between regulator and Stabiliser.
I thought it was Stabiliser for the Fuel Gauge.
On my Sprint i have a Voltage Stabiliser for the Fuel Gauge and a Voltage Regulator for the Generator.
Alan


As far as I know, the regulator is the black rectangular black box at the back top right of the engine bay (looking from the front) connected to the dynamo to control the output from the dynamo. The Stabiliser is a little metal rectangular can with 3 connectors usually fixed to the back of the speedometer which drops the voltage to 10v for some of the instruments such as the fuel gauge and rev counter so that they are 'stable' whatever the speed of the engine is. Alternators have their own regulator built in so you don't usually have an external unit.

Carl

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 2:43 pm
by alan.barker
Thanks Carl,
So we are only talking about Voltage Stabiliser.
Elan feeds only Fuel Gauge.
Elan plus 2 feeds Fuel Gauge , Temp Gauge.
Alan

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 4:14 pm
by Craven
Stabiliser Regulator is purely terminology, the instances used by ?Alan? is a perfect example as both use the same switching principle to allow an integrated voltage to be produce from an ON OFF output.
In purely electronic terms a regulators output is controlled by a feedback process whereby it?s output is continually referred to, usually, an internal reference and adjusted to keep the output constant. FWIW there are both regulators for Voltage and Current.

Re: voltage stabiliser S3?

PostPosted: Mon Oct 22, 2018 5:32 pm
by pereirac
alan.barker wrote:Thanks Carl,
So we are only talking about Voltage Stabiliser.
Elan feeds only Fuel Gauge.
Elan plus 2 feeds Fuel Gauge , Temp Gauge.
Alan



Alan, I think the rev counter also relies on the 10 v from the voltage stabiliser. The original stabilisers are not very good and rely on a little thermal switch which opens and closes, a modern semiconductor version would be much better (and probably produce less radio interference)

Carl

(Planning a visit to Brittany again ext year..)