Snow?

[Kevin Wood]

Quite mild here, actually. Just drove up in the Omega and the MID reckoned it was -19.5, however.

Another job.

Got a brand new one here if you need it 

Thanks for the offer. As it happens, though... It appears that the temperature reading is fine when the front fogs are not on. It's very unusual that I use the front fogs but I found them quite useful for a bit of extra illumination last night when trying to avoid patches of ice. Turns out that the temeprature plummets whenever the fogs are on. I'm guessing the two share a chassis ground somewhere.

[Doctor Gollum]

Under the battery iirc... Certainly upstream of the bumper electrickery connector. 

[Kevin Wood]

Looking at the schematics, I think the fog lights and temerature sensor share a 4 pin connector onto the front bumper so maybe that's where the issue is.
Temperature sensor is two wire twisted pair back to the MID, as might be expected, so it's not directly connected to a ground.

I have recently been wrestling in that area to replace the bonnet latch and the headlamp washer pump, so could be that the connector has been disturbed.

Failing that, the MID and fromt fogs both seemt o use that ground point under the battery, so worth having a look at that.

Once I've welded up the hole in the floorpan, figured out why switching to LPG drops cylinder number 2, etc. etc..

[dave the builder]

Yes , the front fogs and outside temp sensor is the same loom that plugs in N/S
I have a spare loom if you get stuck ,but probably just water in the plug or a rubbed wire ,grounding out .

[Doctor Gollum]

Bumper loom is a separate loom plugged outboard on the n/s chassis rail... Readily accessible on ramps up and back from the n/s fog light. Washer plumbing is a mixture of hardwired from relay box and a plug in the cavity beneath the battery tray

The bulk of the MID wiring is regular 0.5 guage wire, but is hard wired through the bulkhead iirc

[TheBoy]

Looking at the schematics, I think the fog lights and temerature sensor share a 4 pin connector onto the front bumper so maybe that's where the issue is.
Temperature sensor is two wire twisted pair back to the MID, as might be expected, so it's not directly connected to a ground.

I have recently been wrestling in that area to replace the bonnet latch and the headlamp washer pump, so could be that the connector has been disturbed.

Failing that, the MID and fromt fogs both seemt o use that ground point under the battery, so worth having a look at that.

Once I've welded up the hole in the floorpan, figured out why switching to LPG drops cylinder number 2, etc. etc..

Gixer had exactly that issue on that same cylinder.  LPG loom, as you might have already guessed.

[Kevin Wood]

Gixer had exactly that issue on that same cylinder.  LPG loom, as you might have already guessed.

Well, my ear-on-a-stick tells me the injector is firing, just not the cylinder. I think the injector is fubar.

.. and when I looked at the injector I remembered it is Gixer's old set on there after the previous Valtek set started getting a bit lumpy.

[Doctor Gollum]

Gixer had exactly that issue on that same cylinder.  LPG loom, as you might have already guessed.

Well, my ear-on-a-stick tells me the injector is firing, just not the cylinder. I think the injector is fubar.

.. and when I looked at the injector I remembered it is Gixer's old set on there after the previous Valtek set started getting a bit lumpy.

If only every diagnosis was that straightforward...