Cold Start indicator

[slowmo]

I don't have the manual in front of me, but my cold start indicator is on all the time. What is this even for and is the indicator triggered? I am going to tackle gauges and indicators one after the other since none of them actually seem to function.

Thanks.

[lumpydog]

Slo

It's a simple switch. It's clamped onto your choke cable. When you pull out the choke, the switch button pops out (activates the light) as the choke arm/knob is pulled out. Slide the choke in and it obstructs/closes the button, turning the light off.

This one should be simple - remove the 5 instrument panel screws and look for a small box clamped onto the choke cable immediately behind the instrument panel. It's probably loose or maybe slid out of place. The choke cable has three holes in it - two for bumps in the choke light switch box that keep it in place. One middle hole where the choke light switch button protrudes through - and toggles on/off with the slide of the cable.

[slowmo]

Ah. I thought there was a sensor somewhere which gave the indication to use the choke and that the sensor was kaput. Instead, it is just a reminder that you are using the choke. Silly me.

[siii8873]

some systems also have a temp switch at front of the engine near Tstat housing. You pull the choke cable which closes the switch discussed above. This switch is in series with the temp switch. So when you have the choke on and the engine reaches a set temp the choke (cold start) light comes on telling you that you have the choke pulled and the engine is warm.
Probably a problem with the switch noted above it is staying on.

[SafeAirOne]

Well, lumpydog's answer MAY be correct. Some engines had a simple system that merely went through the light switch then to ground as described by lumpydog, and some went through that same switch, enabling the light, then on to a temperature-activated switch (sometimes known as an "otter" switch) on the front of the engine, which illuminated the light by grounding the circuit once the engine is warm, reminding you to "turn off" the choke, so to speak...



[EDIT:] Bob beat me to it--I spent too much time researching the name of the thermal switch.

[lumpydog]

No otter switch on my engine. I wondered how that second temp sensor worked on trucks where I've seen it...

So, if he has one, it sounds like a simple way for Slo to test if it's a faulty otter switch - Would be to see if the cold start light is coming on right away, before the engine is even warmed up. Pull out the choke, and turn the start key to the point where the dash lights come on - but don't start it... and see if the cold start light comes on. If it does, that would point to the otter switch because it's grounding the circuit without the engine being warm. Correct?

But, even if it's a faulty otter switch, the the switch on the choke cable should be able to break the circuit if it's functioning properly...

[slowmo]

I have a sensor which has obviously failed closed AND the switch is closed as well. I looked on our hosts site and didn't find the sensor. Anyone have a link so I can replace it? Thanks.

[SafeAirOne]

They were used on other British cars. Jaguars and MG's come to mind. Google "otter switch" and do "images".

[slowmo]

The plot sickens...er...thickens. One of the PO's removed the switch completely. There is no switch. AND, when I disconnect the spade terminal on the otter switch, the light stays illuminated. So it is either shorted out somewhere, or connected to the wrong terminal. Well...at least this is not a mission critical glitch. Plan is to run new wires from the otter switch, the soon to be replaced water temperature sensor and the soon to be replaced oil pressure sensor.

I will then attempt to find the correct "otter" switch and attempt to find the bracket and switch assembly. Obviously this is not required and I could simply disconnect the light, but what the heck. I like everything tidy.

[lumpydog]

Slo - Our host has the switch you need and I think Ike carries them as well - as mentioned, it's a small box that clamps onto the cable. Make sure your choke cable has the provision for the switch. It should have three small in-line holes on the solid stem that protrudes through the dash panel. If it's a later model S3 choke cable, it may have the switch attachment point on the cable itself, within the engine bay. If you need a choke cable that has the provision for the switch - Ike carries them (they are not entirely easy to find and I do not believe our host has them).

[Edit] Added picture (borrowed from Ike's site) to show the three holes needed for the switch.

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