Thermostat

fortuna1 · Saturday at 13:33

Hi,I was having trouble with my heater on 1990 Defender.Took it to my local garage,he found that there was no thermostat fitted.He fitted one and the heater is now working,but the temperature gauge which was always in the middle of the gauge,in the cab,is now almost touching the red warning limit,any ideas what could be wrong?Thanks

marjon · Saturday at 13:41

Firstly Welcome

.

So a few more details are needed.

Is it really getting hot?
What engine, is it original?

It could be a mismatch of sensor and gauge.

J

Dippypud · Saturday at 13:45

Is the rad getting hot all over or are there cooler spots ?

fortuna1 · Saturday at 13:47

It’s a 200 tdi engine,I did about 20 miles and it was touching the black gap between white and orange on the gauge.I have driven this vehicle for 18 months and the gauge has never gone above midway,previous to this.

Dippypud · Saturday at 13:57

fortuna1 said:
It’s a 200 tdi engine, I did about 20 miles and it was touching the black gap between white and orange on the gauge. I have driven this vehicle for 18 months and the gauge has never gone above midway, previous to this.

Sounds like a mismatch sender/gauge ...

Knappster · Saturday at 14:25

Is it a disco 200Tdi? If so, it’s likely a defender sensor has been fitted, which reads hot.

Phill · Saturday at 16:13

Make sure the sender matches the clock or you'll have a bad time. Better to buy a new one so you're 100% sure its the right one, and that it's not faulty. They're pennies.

dag019 · 2025-03-02T20:08:27+0000

Dippypud said:
Sounds like a mismatch sender/gauge ...

This one ^^

If it is a discovery tdi in a pre tdi “defender” the. The gauge will read in the red hot at normal operating temperature. You used to Get conversion sender to match to the gauge as suggested above from Steve Parker’s. I am sure someone else will be making them as well. If not it’s possible to match the reactance required with some forum searching there are threads detailing how to do it. When I had this issue I just bought the conversion sender.

If it is an original 200tdi with an original gauge then something else is wrong. So you would Need to check firstly if it is actually getting hot, and then secondly either why it’s getting hot, or if not why the gauge is shorting out early to read hot.

Forrest Gump · 2025-03-02T20:45:31+0000

Temp sender is a thermo resistor- need to match it to the engine. Put a new sensor in my 300 tdi and it went off scale. Old one back in just fine. Complicated beasts eh.

lynall · 2025-03-02T20:49:53+0000

I have had a new 200 stats that were no good, one did not open at all, best heater ever!

tottot · 2025-03-02T20:58:18+0000

Me too, I went through 3 replacements in 3 months last year before I found one that worked and kept working.
A new in the box original Waxstat made one.

Thermostat

fortuna1

New Member

marjon

Well-Known Member

Dippypud

Never Knowingly Understood

fortuna1

New Member

Dippypud

Never Knowingly Understood

Knappster

Well-Known Member

Phill

Active Member

dag019

Well-Known Member

Forrest Gump

Well-Known Member

lynall

Well-Known Member

tottot

Well-Known Member

Similar threads