glow plug electrics help

[weldore]

if you connected the first b/w wire to earth(-) and the light didnt come on then that must be the right one greg .now all you have to do is to run it to ground through a sensor...which will give you a resistance to make it go out somewhere between 51 seconds and 0 seconds

[psychonaut]

Found it!!

Okay, so, it was the wire connected to a sensor on the oil cooler. I took it off the sensor, earthed it, and the glow-plug light goes out. Take the earth connection off, glow-plkug light comes on again, all with attendant clicking of the glow-plug relay. However, when I wire it into the temperature sensor on the flange, the glow-plug lights stay on for 51 seconds again. If I pull the plug off the sensor, and earth out the connector on the back (which would be connected to the sensor when fitted) then the glow-plug light goes off again.

So, it looks like a faulty temperature sensor too.

The fact that the sensor would originally have sent a signal to an ECU shouldn't make a difference should it? It's a simple sensor that earths the current when it gets to a pre-set temperature isn't it?

[weldore]

well..its a variable resister mate..its resistance to the earth changes as the temp of the engine changes..or should do.you could try your multimeter on ohms and see if it has an open ciruit.

one thing you could try is to wire it into the temp guage sender and see if the seconds it takes to go out changes

[psychonaut]

Ok - across the terminals, no reading at all.

in a bowl of water at 51 degrees Centigrade - 337 ohms

in a bowl of water at 21 degrees centigrade - 895 ohms

I then compared it to the sort of readings I should be getting on this page: -

http://www.topbuzz.co.uk/maintenance/cts/cts.pdf" onclick="window.open(this.href);return false;

This makes me believe that my sensor could be a bit iffy What do you reckon Mr. Welly?!

[weldore]

so if you run the engine till its warm it should reduce the time it takes to go out..but its an open circuit from cold so its not doing its thing..bit odd that but it could be buggered

it could be,as you said,different for an ecu but when i did the swap i used the original senders from the 1.6 so i cant really do a reading on mine to see if it tally's up with yours

have a read of this http://www.4crawler.com/Diesel/CheapTri ... tureSensor" onclick="window.open(this.href);return false;

[psychonaut]

I'm going to try and borrow one before I buy one as they're the best part of twenty quid.....

I'm guessing your senders have a different housing Wellie if they're the original ones from the 1.6? If I can find the original housing, could I retro fit it, or would that be nigh on impossible?

[weldore]

no,they are a straight swap for the 1y ones.might need some hermetite though

[psychonaut]

Thanks Wellie. If you get a chance, could you possibly take a pic of yours so I know what I'm looking for? Are both housings on the same flange, albeit seperate?

ta

[weldore]

ill take a pic shortly coz im doing the rear bearings today but the top hose housing on mine only has one sender and thats for the glowplugs.the temp guage sender is round the back of the head with the oil pressure one and for some reason i didnt have a sender on the oil cooler housing on the 1.6..so i swapped that too..i only have one wire for the oil pressure ,unless its there and i cant see it

[psychonaut]

Brill, thanks Wellie, that'll be another beer I owes you

[weldore]

your trying to get me tipsy..me finks

[psychonaut]

lolol - rumbled I am

[weldore]

the top hose housing






oil pressure and temp guage sender on the back of the head

[psychonaut]

Wellie, that's brill, I can't thank you enough

Okay, you have an extra sensor in the back of the head on yours that I don't have, so I don't have the option of putting a second sensor there.

A thought - I can get a temp sender for the temp gauge or the glow-plugs that is the same fitting as the one I have and will fit in the housing I have on the top hose. If I got the sender with just two contacts (instead of the four I have on mine) would it run both the glow-plugs and the temp gauge if I wired them both to the same terminal and earthed the other one?

[weldore]

i would think the two readings from the sender would be different .
i dont know it this would work but......what if you got a resistor and ran it in line on the b/w wire and to ground..forget about the sender all together and see if you could get a resister that matched the sender reading so it goes off after say 7-10 secs...all the time.
you could live with that..couldnt you ?