Temp light flashing And needle shoots to top.

[stevelane]

The above could make sense if I was on the motorway but I have literally only just started the van when the above happens

Any suggestions?

[colinthefox]

The low coolant level warning system does this.

It is usually

EITHER

Because the warning system is working correctly, and the coolant level in the reservoir (right hand side of engine compartment, not behind the cat flap) has got low. The reservoir should be brim full.

OR

The warning system isn't working because the wiring has a break. There is a two pin connector on the top of the reservoir, and the pins/spade connectors can corrode, or sometimes the wiring rots inside the PVC insulation up to several inches from the connector. Cure is new wiring and connectors.

The problem could also be behind the dash, but if I was a betting man, I'd look here first.

[marlinowner]

Pull out relay 43, coolant level warning circuit. If fault disappears it is as above, if it is still there then probably a fault with the coolant temperature sender or wiring to same.

[Bubble Meister]

But that shouldn't make the needle shoot to the 'top' (I assume full right). The low coolant only pulses a 'hot' signal, enough to trip the light but not enough to move the needle. I'd say its more likely the temp sender. Check it's not earthing or the wiring isn't earthing.

[marlinowner]

Early ones send the gauge to the top AFAIK. Not sure when the changeover was though.

[Bubble Meister]

I may stand corrected but this is how mine had worked: I have the early system with early fusebox. I had corrosion on the low level plug so the light would trip within the first few mins of the engine starting. The needle still indicated respective to the engine temperature.

[ChrisTriple]

I have an early van, if the water is low the red light flashes and the temp needle shoots to the top. It could be that the sensor is dirty and just needs a clean

[Smiffo]

Early ones send the gauge to the top AFAIK. Not sure when the changeover was though.

I thought I read that somewhere too Marlin.
Moki however, mentioned to me that he has ( or has had ) two early vans, and neither of his send the needle to full temp when the coolant is low, he only gets the flashing light.

Perhaps it depends on whether you have relay 43 or 42 ?
( I am only speculating there. )

I did try to test it out on my late van, but quickly found that the low coolant indicator circuit doesn't work at all on my van.
Normal temp does, but not coolant level.
I will look at it after the summer - At the moment I am just enjoying having the van on the road

As for the OP - I would at least check the coolant level and coolant level sensor circuit as advised in this thread, if for no other reason than to eliminate the possibility.

[Bubble Meister]

Well Chris, two early systems but different effects. Weird. My relay is not on the fusebox but on the bulkhead just above the fusebox. It all appears standard and as per Bentley manual.

[Bubble Meister]

Smiffo, I couldn't tell you what the relay number is, I've never had to remove it so not noticed.

[marlinowner]

Apparently there are early and late versions of 43, early one (up to some time in 1985) sends the gauge to the top, later one doesnt. 42 replaced 43 on later vans and doesn't affect gauge reading. Of course any van could have any version fitted by now.

[stevelane]

Cheers for the suggestions guys. It's an 1984 van. I'm new to t25 ownership so I appreciate your advice, I'll check tomorrow and report back

[Smiffo]

Apparently there are early and late versions of 43, early one (up to some time in 1985) sends the gauge to the top, later one doesnt. 42 replaced 43 on later vans and doesn't affect gauge reading. Of course any van could have any version fitted by now.

That makes perfect sense to me. Especially as several different owners of early vans depict differing results when in similar situations.

[Smiffo]

Cheers for the suggestions guys. It's an 1984 van. I'm new to t25 ownership so I appreciate your advice, I'll check tomorrow and report back

Let us all know what you find Steve - and good luck

[stevelane]

All sorted guys. Coolant was a little low and the sensor was gunked up. Rectified both and no flashing lights. Appreciate your help