Temp sender / guage

[GroovyCarrot]

My temp guage went haywire yesterday.. all of a sudden it's decided that before the engine's even been started it's going to show half way up the guage, and when I reach normal running temp the needle hits the top of the guage, then the warning light starts flashing. The warning light seems to flash or not according to what other electrical components are turned on at the time - turning the indicators on seems to stop it for a moment, then it'll go to solid red, then it'll start flashing again
When I unplug the black temp sender it just goes back to the bottom of the guage as usual.
Is this likely to be the guage or the sender? Any way to test the sender?

I'm pretty sure it's not actually overheating, as I'm just running it as I normally do, the coolant level is full and the fan still comes on after the normal period of time, although by that time the guage is already off the scale

[GroovyCarrot]

Oh, and another thing, what's the blue temp sender used for on a mk2? I know it's used by the electronic gubbins in a mk3, but I can't find any use for it on mine.. if I unplug it I can hear a relay clicking somewhere, but it doesn't seem to actually change anything.

[ste mk1lx]

Oh, and another thing, what's the blue temp sender used for on a mk2? I know it's used by the electronic gubbins in a mk3, but I can't find any use for it on mine.. if I unplug it I can hear a relay clicking somewhere, but it doesn't seem to actually change anything.

IIRC the blue sensor is used by the inlet manifold heater, it senses water temp then switches off the heater element

[GroovyCarrot]

Ah, gotcha, ta
Anyone got any ideas on the guage..?

[Tahrey1043]

....

i cant resist

Sounds broken.

[GroovyCarrot]

...thanks tahrey, what would I do without you
I aiming more at which bit of the circuit's broken I'll just try replacing the temp sender and see if it fixes it.

[GingerNik]

My temp sender's a bit mad too - sometimes it doesn't work at all, sometimes it works straight away.

Always seems to work when starting the car with a warm engine though..

[amstrange1]

The one on my Coupe S seems a bit intermittant too. It didn't work at all for ages today, then all of a sudden sprang back into life.

[GingerNik]

Nottingham Uni eh? Same as me - your car isn't F reg and red is it?

[amstrange1]

I normally drive a green K-reg Mk3 Polo CL squareback, lowered on 13" BBS with a 160bhp G40 lump in it. But that's off the road at the minute, so I've bought a metallic grey F-reg Coupe S to keep me mobile. It's lowered on 14" BBS, so if you see me about give me a wave!

Whereabouts you live, and what do ya drive?

Andy

[GingerNik]

I live on Broadgate Park - got a Blue 1.3 Boulevard Coupe.

Wish I had a 5 speed gearbox though!

[k4lps]

The one on my Coupe S seems a bit intermittant too. It didn't work at all for ages today, then all of a sudden sprang back into life.

thats what mine does

[amstrange1]

I live on Broadgate Park - got a Blue 1.3 Boulevard Coupe.

Wish I had a 5 speed gearbox though!

I couldn't live without 5 gears!

What year/course you in? I'm a 3rd year Elec Engineering student, live out Lenton way.

[GingerNik]

2nd year mechanical engineer - sitting at 70 in 4th does get a bit tiresome at times!

[polo magic]

Hi people, only had Polo C a week(D reg 1987).....have noticed water temp light flashes when ignition turned on....sometimes stops b4 starting....sometimes not......also flashes whenever it feels like it whilst driving. Temp gauge dosnt register overheat and am not loosing water.......any ideas???