Club 80-90 Forums

I have a 1.6TD camper and the glow plug light normally takes about 45 seconds to go out - is this normal or does it indicate a problem with the ignition system.

The light has done  this since we got the van 4 years ago but recently the van has become very difficult to start ( it used to fire up on first turn of the key ).

Is the 45 seconds an indication that either the relay or the glowplugs are on the way out ?

Thanks for any help.

Ian.

The glow relay calculates the glow time from a temperature input. The input is a resistance to ground through a standard temp sender in the coolant flange in the cylinder head. If the resistance is infinite (bad sender or broken wire) then it thinks the temp is below -20C.

I assume the wire broke or the connector fell off the sender.
The wire is a blue with white stripe. On later vans with plastic flanges the ground also has a brown wire.

The early relays had longer pre-glow times BTW.
 

its pretty normal

Hi ZsZ,

Thanks for your reply. 

I've just had a look at the connections you described - my van is a 91 model but it has had an engine change at some point.

There is a plastic connector with a brown and a red/brown wire coming from it hanging loose in the engine bay with the red/brown wire cut and I'm assuming this was the connector for the temp sender on the original engine.

The current setup on the van is a blue/black wire coming out of the original wiring loom and connected to the sender screwed into the back of the cylinder head .  

Is there an easy way of testing the sender insitu - say with a multimeter.

If so can you explain how to do this in laymans terms as auto electrics is not my strong point.

Thanks for your help.
Ian.

 

Hi ZsZ,

I've just had another look at the engine and I'm now wondering if I am looking at the correct sender because just below the sender I described as being screwed directly into the head just below the rocker cover I have noticed there is another flange with a hose coming off it and an electrical connector/sender screwed into the flange - this connector does not have any wire connected to it. 

Is the sender you are referring to the upper one with just an electrical connection or the lower one with the rubber pipe and an electrical connection.

Thanks again,
Ian. 

Hi Ian,
Sorry I was offline for a few days.
I assume you have the late system with plastic coolant flanges as it is a '91.

The temp sender of the glow circuit should have a blue/white and a brown wire in the connector.
There is a second temp sender somewhere with a connector that has black/yellow and brown wires. That is for the temp gauge.
The brown/red wire should go to the thermoswitch of the aux. water pump. That connector also should have a brown wire on the late system. If it is not connected then the aux. eletric water pump will not pump coolant through the oil cooler.
I am not sure where they are located by standard, but they should all live in a coolant flange on the engine.

The senders and the switch look similar:
switch: https://www.brickwerks.co.uk/coolant-te ... -late.html
sender: https://www.brickwerks.co.uk/coolant-te ... green.html

The other sender which is screwed into the head is an oil pressure switch. It should have a single blue/black wire connected:
https://www.brickwerks.co.uk/oil-pressu ... -blue.html

Post some pics of your engine to see which is which and where they are located.

If you find the connector with the blue/white wire then you can check the wire for breaks with a multimeter that has the beeper for continuity testing.
If you remove the glow plug controller "relay" from the black box on the left side on the firewall then you can access that side of the wire. It is the one marked with a T
Connecting one lead of the multimeter to the T pin of the relay socket, the other lead to the blue/white pin of the wire in the sender connector the meter should beep.
You have to check the other brown wire. It should be connected to ground, so one lead of the meter going to the pin of the brown wire in the connector, the other to the battery negative post and the meter should beep again.
If there is no beep then there is a break in that line you were testing.
There is a second temp sender somewhere with a connector with black/yellow and brown wires. That is for the temp gauge.
You can test the sender by switching the multimeter to measure resistance (ohms) it should have some resistance between the two pins. The value varies with the coolant temperature. It should read between 2-3 kOhms at 20C and around 200-250 Ohms at a hot engine (90C)

Thanks again ZsZ that's all very helpful.
I'm off in the van for 10 days so won't be carrying out checks till I get back.
Is it OK to PM you if I need any more info.

Ian.

Sure, PM me if you stuck.
Have a nice trip!