7 replies to this topic

[maka]

Hello guys,

How easy or difficult is it to replace a water temperature wire? the one that goes from the sensor to the gauge. It seems the one that I have is giving too much resistance, which make to gauge read Hot, I think I need to replace it. I’ve tried with a new wire and the resistance is much lower.

Thank you.

[phil hill]

 Hi Maka.

 

You do know that there are different types of sender which has to match up with the gauge to give the correct temperature reading ??

 

It is more likely you have the wrong sender/gauge combination than the wire being "wrong", unless the wiring loom is damaged, melted or shorted to another wire somewhere.

 

Did the gauge ever read correctly in your ownership, and if yes have you changed anything since ??  Replacement cylinder head, engine, sender or gauges ??

 

Phil.

[Spider]

Hi,

 

I don't think the issue here would be the wire, for a few reasons. I'd say, it's the wrong sender. I've found all senders currently available do read 'hot' (or I haven't found ones that do read correct).

If it was the wire, 'adding' resistance would make it read colder, however, wires being what they are, for the most part, they either work or don't. You can get intermittent issues, though this would usually show up as working until you hit a bump, then it would stop, next bump, it might work again.

[lordcakes]

If you have got the correct sender and have traced the fault to the wire (you said that you substituted it and got a lower reading) then first check your connectors and joints, the most obvious being the connector at the sender and the connector to your gauge - check for damage, breaks, corrosion etc. If you have a multimeter check the resistance of the cable, if resistance should be very low, anything else and you are likely to have a break or dodgy connector. On my mini the wire for the temperature gauge has no joints, just the connector at either end.

[maka]

Thanks for the help guys,

I bought the gauge and sender unit new all together from a guy, he told me that they should match.

I ended up replacing the connectors and measured the resistance and I got 7.5 on the multimeter I did the same with a new wire and same new connectors and measured 0.5.

With the new wire the gauge get to N after a couple of minutes when engine is running. Maybe the old wire is corroded somewhere ?

Edited by maka, 20 February 2021 - 07:00 PM.

[lordcakes]

Something isn't right. The resistance of the wire should be almost 0: if you have put new connectors on it then it either has a break or something is not quite right with the configuration of the original setup. I'm just wondering how your old gauge is wired in - is this an original factory fit gauge or a later fit? Does the old gauge go via the voltage regulator and could that be the problem area? And could a previous owner have done something silly like reusing the wire for the ballast ignition to feed the temp gauge rather than running a new wire through the engine bay?

[sonscar]

The original wire probably has a fat spot where the conductors have corroded and swelled due to water ingress.Steve..

[Steam]

If the new wire fixes the fault, just cable tie it to the old loom and connect both ends. Job done.