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temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 19:20
by stives_daz
Hi all

I have a 1989 1.9 watercooled camper.

I need some help, I've had the van for a few months with no problems so far, but I've been unable to use the van recently and I went to start it up this afternoon and the red light stays on while the engines running. I left it running and it does not over heat, so I'm guessing that it could be a sensor issue. Spoke to a friend about this, and he said it might just need topping up.

I think I may have made an error though, I'm not great working on engines and not knowledgeable with T25 is very limited, so far. So I ended up filling the cap behind the number plate with blue antifreeze. Only up to the maximum level. Now I'm reading more into it, have I done the right thing as it appears there are two places to top up. One behind the numberplate and one in the engine bay. Was I OK to do this? Or should this area stay empty? Shall I remove some of the antifreeze I added to the expansion tank (about a pints worth) or will it be OK?

I never checked the level in the engine bay, but the expansion area was empty and I filled it up to the max. So after reading more about it on here, this area seems to be for the coolant to fill up while the engine gets hot, hence why its called the expansion tank (I have just found this out). Plus the red light is still flashing on. So tomorrow I will check the headertanks levels. And maybe go for a long drive and see if the temp light goes off.

Any guidance would be grateful recieved

thanks all

Re: temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 19:31
by Mocki
worry not, you have done right so far, but you DO need to open the trapdoor of doom and check the level in the headertank, odds on it is low, which is why the flashing red light......
the headertank needs to be brimming full......

if it is full ( i doubt it if the top up tanks was empty) the sensor could be corroded, or the connections dirty.

dont be going for long ridies untill you are sure the levels are correct

Re: temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 19:49
by stives_daz
thanks Mocki for your reply

the headertank cap, is it clearly marked so I don't go filling up any old tank? :D

Re: temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 19:53
by Ian Hulley
Open the lid, bottom left with a blue or black dalek shaped lid. Make sure there's a hose from the dalek to the top-up tank :pimp

If you're stuck and can wait till May we'll be coming to your's and we'll have a butchers for ya :ok

Ian.

Re: temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 19:58
by Mocki
did i miss that, a meet in Ely in may?
ill go!

you cant miss the headertank, open the engine lid (trapdoor of doom) and with you knees by the numberplate, its just below your left hand as you stand there leaning over peering in...... like Ian says check the pipe to the top up tank is there, and not leaky if it is there

Re: temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 20:03
by stives_daz
cool cheers, I'll let you know how I get on.

Keep us posted on any meets you are having this way, I need all the help I can get understanding these things. And its always good to meet fellow dubbers :D

Re: temperature light flashes - have I made a mistake?

Posted: 15 Feb 2009, 20:12
by Ian Hulley
I assumed the 'stives' implied you were in that fair town :mrgreen:

Silly me ! :rofl

Ian

Re: temperature light flashes - have I made a mistake?

Posted: 27 Feb 2009, 19:01
by stives_daz
I did live in st.ives for a while and ended up moving near Ely. I carried on using my stives_daz login name for forums, as my brain cannot cope with the huge amount of password & logins detail needed these days :D

Update on the van, the red light as now gone. All thanks to topping in up! cheers all.

All I need to do now is get the engine serviced and tuned up. And find out why a strange squeaking noise is coming from one of the wheels when I drive along. suggestions? brakes> bearings? :roll:

Re: temperature light flashes - have I made a mistake?

Posted: 27 Feb 2009, 19:13
by Ville666
Hi,, sorry to butt in but i have a similar problem too on my 2.1, coolants fine, temps fine just this damm flashing light constantly,,,, does any body know if there should be 12v at the sensor plug when the ignition is on?? blue and green wire on mine traced this back to the harness conector which i seperated and no 12v there either,

Re: temperature light flashes - have I made a mistake?

Posted: 27 Feb 2009, 19:37
by AngeloEvs
IIRC you shouldn't have 12V on that wire to the coolant level sensor. Will check my notes but seem to remember It is a pulse that is fed into the probe every few seconds (and difficult to read on a multimeter!). Usually a poor earth connection if everything else is OK.

Re: temperature light flashes - have I made a mistake?

Posted: 28 Feb 2009, 12:39
by AngeloEvs
To test the signal from the LSCU (level sender control unit) to coolant level sensor:

1. Remove the plug on the header tank.

2. Set your multimeter to AC and set the voltage to read 2V, 10V or any value thereabouts.

3. Switch the ignition on (LED will self test, then extinguish then after a few seconds resume flashing.

4. Place one multimeter probe to the engine block or known earth (don't rely on the brown wire at this stage as it may not connect to earth and be the cause) but you can check for Earth continuity after this test.

5, Place the other probe on the Green/Blue pin. You should measure approx. 1.5V to 1.9V ac.

6. If this proves OK then check all earth points in the coolant wiring. I posted a simplified circuit in another thread which may help you.

Hope this helps!