Glow Plug circuit checking

[DeeTees]

I have difficult starting when cold, but normal starting when engine is warm.
I'm currently checking the glow plug circuit.

My voltage tester has gone into hiding, I'm just using a mini led current tester.
With ign on and open bonnet, maybe I heard just one click after a few seconds. With the ign on, I have no current where the wire comes to the first glow plug on the buzz bar.
At the glow plug electrical connection, where the wire with current enters, I got a bit of a red light on the led current tester for a few seconds. I tried unsuccessfully a few times afterwards to repeat that, but (a) I didn't connect in properly with the tester, (b) there was no current, or (c) I got slower.

Anyway, when I unplug the wire from the glow plug electrical connection and connect a similar gauge wire (from the positive terminal on the battery) into it, I can start the engine immediately, like normal.
Because of the one time I got a bit of voltage, I suspect the (very well hidden) glow plug relay.
There is also a 80 amp fuse somewhere, but where?
Is it in the relay/fuse box beside the fuel filter. I only see one possible suspect in there, a 75 amp fuse, labelled on the box cover as "FL 75A main".

 

[zippy656]

GLOW - Wiring diagram...............................EC-241
Glow control system.....................EC-239, 311, 389
Glow plug .............................................EC-239, 390​

Glow relay ............................................EC-241, 396

in the manual link below

http://bebrs.pie-dabas.net/Webs/Terrano/R20/ec.pdf

 

[4wheel]

Could be the fuse but the culprit sounds like the relay behind the battery.I had the same problem and replaced the relay and starts first time.I managed to do so without removing the battery as did not want to disrupt the alarm system.

 

[glen]

wire broken

I had a broken wire from the connector to the first glow plug on the buzz bar
took days to fined. but it was ok when warm.

Glen

 

[DeeTees]

Thanks for the replies and the link to the manual is much appreciated but I'm still none the wiser as to where the 80a fuse lies, somewhere in a secret location between the battery and the glow plug relay.

Can it be the "FL 75A main" fuse in the fuse box (beside the fuel filter)?

 

[rayf3262]

Thanks for the replies and the link to the manual is much appreciated but I'm still none the wiser as to where the 80a fuse lies, somewhere in a secret location between the battery and the glow plug relay.

Can it be the "FL 75A main" fuse in the fuse box (beside the fuel filter)?

On some vehicles there is a fusible link in the wiring loom, rated at 60~80 Amps, could easily be that.
Its close to battery & engine coolant bottle.
From memory it looks just like a piece of cable with some sleeving over it, not easy to find if you don't know its there!

 

[DeeTees]

Well I heaved out the battery and I have voltage on the white wire going into the relay and according to the diagram on ec392, that is the wire coming from the 80a fuse. I'll check further to see if there is current coming out of the relay

 

[DeeTees]

Just to add a happy ending epilogue.
At the time I wasn't able to test if current was leaving the relay but I ordered the new relay regardless. It arrived 9 days later and once installed the glow plug circuit was fully functioning.
While I was waiting for the relay I made this for easy starting,

used only once a day, now stored in the toolbox

 

[rustic]

Just to add a happy ending epilogue.
At the time I wasn't able to test if current was leaving the relay but I ordered the new relay regardless. It arrived 9 days later and once installed the glow plug circuit was fully functioning.
While I was waiting for the relay I made this for easy starting,

used only once a day, now stored in the toolbox

I am not that impressed, if this is how you leave it after you have started.

If the relay was intermittant, the next time you start it when warm, if the relay works, then you will short out the supply, as you have earthed the croc clip on the battery clamp. This would probably burn out your link wire.

It is important for other readers of this thread to consider this issue before they do a similar modification....

 

[rayf3262]

At least the connector to the relay has been disconnected from the glow plug circuit, so should be ok.

 

[DeeTees]

At least the connector to the relay has been disconnected from the glow plug circuit, so should be ok.

Exactly, it was okay and still is. I don't see how any harm can arise. The relay was not involved.
After starting, I removed both the clamp from the battery and the blue wire from the glow plug electrical connection. But there would be no damage done by leaving the cable in place, as you see in the picture.