Temp gauge issue

[t.onyb 31]

Hi all,

 

Having a long ongoing issue with my temp gauge.

 

I have a 3.0 MK3 and the temp gauge don’t work? Yet, if I earth it the gauge works fine. I have changed the sender three times but the issue remains.

 

Both work fine, but when I connect them nothing works.

 

Im no mechanic so please don’t blind me with science.

 

Any ideas please????

 

Tony

[Beeper 82]

Err, do you have a thermostat fitted and if you do, is it stuck in the open position?

[t.onyb 31]

Yes I have a thermostat - recently new with the sensor, points, plugs etc.

 

How do I check this?

 

Never considered the thermo?? Do you think this is a genuine fix?

 

Thank you 👍

Edited May 30 by t.onyb

[sheffieldcortinacentre 753]

Won't make any difference to the gauge. No stat will just read low/take longer to register.

 

Does the fuel gauge work? If not the ballast resistor on the rear of clocks has failed ( it's a small silver box( you must get a mk3-4 Cortina one).

You must get the correct sender for the eng too it's a bullet terminal one with a white insert ( again if not it won't read correctly) you say the sender works how do you know,how did you test it?

[bortaf 94]

where are you earthing the temp cable ? just asking incase the small earth is missing on the rear of the head and the head isn't referanced to neutral ?

[t.onyb 31]

17 hours ago, sheffieldcortinacentre said:

Won't make any difference to the gauge. No stat will just read low/take longer to register.

 

Does the fuel gauge work? If not the ballast resistor on the rear of clocks has failed ( it's a small silver box( you must get a mk3-4 Cortina one).

You must get the correct sender for the eng too it's a bullet terminal one with a white insert ( again if not it won't read correctly) you say the sender works how do you know,how did you test it?

Fuel gauge works fine Craig

Got a new sender from Burtons so I assume it is correct for my engine - no not tested??

 

[t.onyb 31]

2 hours ago, bortaf said:

where are you earthing the temp cable ? just asking incase the small earth is missing on the rear of the head and the head isn't referanced to neutral ?

Just took the cable off the sender and touched body - gauge moved to top.

[sheffieldcortinacentre 753]

2 hours ago, t.onyb said:

Fuel gauge works fine Craig

Got a new sender from Burtons so I assume it is correct for my engine - no not tested??

 

AHH that could be problem.

[t.onyb 31]

Mystery ???

[TimB 102]

With the ignition on, what happens if you touch a test cable from the sender unit body to the battery earth? i.e. does the gauge go hot?

[sheffieldcortinacentre 753]

Burtons & there Chineseium tat.

[t.onyb 31]

3 hours ago, TimB said:

With the ignition on, what happens if you touch a test cable from the sender unit body to the battery earth? i.e. does the gauge go hot?

Yes, rises up as if hot. When reconnect to sender it don’t move.

[sheffieldcortinacentre 753]

That shows wire & gauge are making a circuit & sender is faulty ( see above re burtons).

Edited June 1 by sheffieldcortinacentre

[t.onyb 31]

6 hours ago, sheffieldcortinacentre said:

That shows wire & gauge are making a circuit & sender is faulty ( see above re burtons).

Do you have one Craig? The right type that works? Can we meet up at the weekend in Yat?

Thanks - Tony

[TimB 102]

8 hours ago, t.onyb said:

Yes, rises up as if hot. When reconnect to sender it don’t move.

I meant leave the original cable on the sender and use an extra test cable, this will test the earth connection between the sender and the engine block. 

Probably is the sender but doing this may show if the earth route from the sender body is not good.

Good luck.