Coolent sensor lead help

[Michael Montgomery]

Guys been a while but noticed my temp gauge on the dash isn’t working correctly.

The cable has noticeably gone missing in the engine bay on the sensor. I’ve found what I think the missing cable is but nothing changes when plugging it back in.

Does anyone have an idea where the cable traces back to so I better isolate the issue.

Thanks in advance

 

[Dave2000]

If the lead fell off and touched earth the gauge would go right off the scale. If the gauge actuation is the same style bi-metallic strip as per the oil pressure gauge the result is the small spring drops behjnd the needle, so there will be no needle deflection regardless of engine temp....ask me how I know.

Switch on the ignition and have someone watch the gauge, earth the cable and see if the needle moves towards hot, if it does then stop there and get a new sensor.

If not then perhaps you need to pull the dash and see if the spring is connected to the needle correctly, BTW unless you have decent eye sight grab a magnifying glass as the spring/needle relationship connection is small.

Regards

Dave

 

[Michael Montgomery]

Hi Dave thank you for time to reply.

I found a wire coming from under the fuse box but unsure if it’s for the sensor however the black cable has a green single wire poking out of it around 1 inch and the wire exposed there after.

We tried the other day to ground it with the ignition but the needle didn’t move. The water gauge on the dash does eventually move up to temp but not when it should do after warming up.

Thanks

 

[Michael Montgomery]

Update still no fix guys this is a single lose wire that traces back under the fuse box. Not sure but if anyone can help & share where the wire / cable traces back to would be very handy.

It may be the female connector and come off to attach it back?

Thanks

 

[Dave2000]

That definitely looks like the temperature gauge wire, green with black outer protection, this protection stops it rubbing through and going to earth and messing up the gauge, which you may have already have a problem with?

The sensor missing a cable might be a clue as the sensor is in the right place to monitor temperature.

Regards

Dave

 

[Michael Montgomery]

Having looking everywhere this is the only wire thats loose and missing a connector Dave. Just confused to it being a single wire and not double. My next move is to find a suitable connector for it to attach onto the temp sensor and hope that works. Not sure what happened to it tbh.

Currently the gauge works but there's a lag in the rising temperature on the gauge on the dash so fixing this will hopefully correct this.

Thanks for you help

Dervis

 

[Ben Stratford]

How long is the lag Dervis?
I would expect it to start moving after a couple of km’s at the most
When it does start moving, does it reach the right temperature?

 

[Michael Montgomery]

How long is the lag Dervis?
I would expect it to start moving after a couple of km’s at the most
When it does start moving, does it reach the right temperature?

It depends Ben its differs time to time but sometimes can take up to an hour to show the needle in the right place, other times far less. Normally would do so after 5 mins or so for what I recall previously as theres other temp sensors on the engine block too.

Right now its too slow and not accurate by far.

The earlier models didn't have a sensor here so haven't come across another 92/93 model and above to check there engine bay of late here.

 

[Ben Stratford]

I cant understand how it moves at all with no wire connected to it.
Are you sure you have the right sensor identified?

 

[Michael Montgomery]

I cant understand how it moves at all with no wire connected to it.
Are you sure you have the right sensor identified?

Pretty sure there Ben just don't think on the 1HDT theres one sensor to give the reading. It feels like its a combination or several over the engine to give a more accurate reading.

 

[Dave2000]

The gauge is activated by earth return, i.e. one wire. Looking at your picture where the sensor is, and the length of the wire available it almost certainly came from that sensor. Best to follow the cable colour on a wiring diagram Dervis.

Regards

Dave

 

[frank rabbets]

Yes single wire with earth through block being the second "wire". I would have a look inside the mouth of the sensor. It could be that the connector for the wire is still on the sensor pin somebody having pulled the wire but left the connector in situ. One should pull the connector not the wire if possible.

 

[Michael Montgomery]

Having a good search around found what seems is the female connector clearly showing the broken green wire inside. Extended and soldered to make it as good as new. Hopefully upon driving all will be back to normal guys.

Thanks for you help