Hanging Microswitch

[rolfe]

Whilst exploring the complexity and fine british craftsmanship of the wiring loom of my 92 4.3 which hangs tantalisingly over the top of the battery box I have come across a microswitch which is just hanging there. (Along with several important looking relays which obviously have been designed to hang there!). I reckon it does something and should fit somewhere ie not just hang - Whats it for and were does it fit? Any help would be appreciated

[davidn]

I thought the micro switch was to reset the fuel pump when it cuts out due to accident or similar nastiness, could be wrong though.
David

[GreenV8S]

Offhand I can't think of anything in that area that uses a microswitch - unless the door switch has come adrift? Is there any power to it? Does anything happen when you operate it? Do your interior lights still work porperly?

[rolfe]

No everything appears to work fine. Its a very light microswitch about 25mm long x 20 wide x 4mm deep with an actuator arm and small nylon roller. I have not checked if it has power to it yet as I am curently working on the theory of leave alone till I know what it is!!

[GreenV8S]

Don't suppose you have any extra lights in the glovebox or something like that?

[rolfe]

No. The wire lengths suggest it stays in the footwell.

[ATG]

I was about to ask if it looks like it has been added as an after-thought, but that isn't likely to distinguish it from any other part of the wiring.

I guess someone might have hooked it up to an ECU reset line, if there is such a thing, but why would anyone want/need a permanent fixture for resetting it?

Alarm switch for the bonnet might be fitted (by a maniac) through the top of the footwell, but hard to see how it would fall all the way back through, and the alarm should have gone mental.

The only thing I can think of that has a moving part in that area might be a valve on the heater matrix?? Any chance the switch is used to sense when the valve is fully open or shut?

[david beer]

There are two micro switches on the "recirculate",and the "air direction". Well there is on a 99!!

[davidn]

So if the micro switch is nothing to do with the fuel pump where is it the reset? I thought I read somewhere there was one.
David

[rolfe]

Guess I better look at the heating matrix. Without sounding to dum whats it likely to do?

[GreenV8S]

davidn said: So if the micro switch is nothing to do with the fuel pump where is it the reset? I thought I read somewhere there was one.
David

On the V8S the inertia switch is a rectangular plastic box about 2" wide and 3" high with a button on top, under the bonnet on the outside of the passengers footwell, just above the washer bottle. The button pops up on impact and you push it back down to reset it.

I think the arrangement on a Chimaera is slightly different and if memory serves you have a rollover valve in the boot by the filler neck, and an inertia switch under the dashboard on the passengers side. But its been a long time since I saw one so I could well be wrong there. In any case its worth knowing where these things live, the inertia switch on the V8S triggered the other day for no apparent reason after behaving perfectly for the last 120,000 miles. I thought the fuel pump relay gremlin was back, but luckily it was a separate and much simpler problem to fix.

[IPAddis]

david beer said: There are two micro switches on the "recirculate",and the "air direction". Well there is on a 99!!

Agreed, probably part of the heater control system. Stops the valve from turning too far.

Ian A.