Water temperature gauge failure

Post by **mgcjag** » Sun Jan 03, 2016 1:44 pm

Hi Yves......the type of meter you have is all that you need to work on your car electrics......the only problem is that from a photo we cant see if the meter is actually working.......what reading do you get when you just connect the two leads together it should be zero ohms and when you test the temp sender it should be a bit higher resistance

cactusman · Post by **cactusman** » Sun Jan 03, 2016 3:12 pm

Agree...your meter is fine....just make sure when you are measuring resistance that it reads zero with the leads shorted before you take your meqsurement. If not find that zero knob and adjust.

You do see unloved Avometers about. I picked a lovely one up at a car show for ?20. They are much more robustly made than modern meters and are more forgiving of overload as they have resettable cut outs. I luv 'em. Built when things were built to last.....like E types!!!!!

Keep us all posted....I am sure a fix will be apparent before long.

Polse7317 · Post by **Polse7317** » Wed Jan 13, 2016 3:11 pm

I have adjusted my ohmmeter and found +- 630 ohm on the cold temp sender and +- 0 Ohm in boiling water. So it's correct , I must now check the gauge .....
I have another problem with the cooling system: firsteval the cooling fan does'nt work when the motor is hot... ( test motor itself OK) . When the motor turns with the fan connected on the battery , the coolant boils and overflows by the headertank pipe . I tried without the thermostat and I have the same result....the water pump turns , it seems like the coolant is not circulating everywhere ? and the drain valve leaks out ! ( It's a new one I have already changed this one before ( another new one....!) but it has broken when I turn it !)

I am quite disapointed with all theese problems!

Post by **mgcjag** » Wed Jan 13, 2016 4:08 pm

Hi Yves........the fan is controled by the otter switch that operates the fan relay that switches on the fan....power to the relay is via a fuse.......

Polse7317 · Post by **Polse7317** » Wed Jan 13, 2016 7:02 pm

Hi Mgc, can you tell me where is the fan relay and its fuse (in the dash board?)

Post by **mgcjag** » Wed Jan 13, 2016 7:44 pm

Hi Yves.....fuse in the dash.....relay on your S1not sure i have a S2....any one...?

Polse7317 · Post by **Polse7317** » Wed Jan 13, 2016 7:49 pm

I'll search the relay tomorow ( busy day today.....!) and check the fuses .

Post by **mgcjag** » Thu Jan 14, 2016 10:20 am

Hi Yves.....have a look at this post.....it refers to late 3.8 and early 4.2 cars do not vave a fan relay, just the fused supply and tbe otter switch... Steve viewtopic.php?p=33010&sid=000872356f517 ... 4523f0107a

Polse7317 · Post by **Polse7317** » Thu Jan 14, 2016 11:38 am

surprise this morning, when I started the motor, the temp gauge shows +- 55C? when the motor is hot .... may be it's not the right temp...? but the gauge has moved ...in the rignt way !
About my fan motor which doesn't start
I found on the wiring loom from SNG that :

It seems that the fan relay must be connected there . But the original loom has not theese connections, anyway I think I have to fit a fan relay here if I don't do a mistake.
( thank you MCGJAG for the link, it has helped me to understand my problem )

Polse7317 · Post by **Polse7317** » Fri Jan 15, 2016 4:49 pm

New surprise today.... the gauge does'nt move even with a hot motor.... I really don't understand why . I'll change the stabiliser in the dashboard and see what happens....

Post by **mgcjag** » Fri Jan 15, 2016 5:08 pm

Hi Yves...sounds like a possible loose connection..try moving some of the wires about...keep smiling and enjoying it

Polse7317 · Post by **Polse7317** » Mon Jan 18, 2016 10:05 pm

I tested the gauge yesterday..... it was ok ! y must check as you say a loose connection.
Y bought a fan relay ( sngB ) and I tested it on the car but it does'nt give the fan moving with those connections:

Where is my mistake? I followed ( I think) the wiring diagram...?

cactusman · Post by **cactusman** » Mon Jan 18, 2016 10:41 pm

The original fan relay had W2 and C2 internally connected. C2 was green power feed. C1 went to the fan and W1 went to the otter switch.

Your three connection are fine but the green wire must also be connected to your W2 terminal to provide power to the relay coil. Then your relay should connect C2 and C1 when the otter switch closed and, hey presto, your fan will go. Make sure it blows the right way though. J

Polse7317 · Post by **Polse7317** » Tue Jan 19, 2016 6:55 am

Thanks cactus man, I'll try that this evening ...

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

Link:
BBcode:
HTML:
	Hide post links

The 'E' Type Forum

Water temperature gauge failure

#21

#22 Water temp

#23

#24

#25

#26

#27

#28

#29

#30

#31

#32

#33 Fan relay

#34