Quote:
Originally Posted by 11ford11
Are you sure it doesn’t switch the earth side of the relay to pull it in
Check with a test light or multi meter for power at relay contacts and see if you loose it when you remove glow plug fuse
Bridge relay socket contact connections while checking for power at glow plug connections.
Don’t leave on long time just long enough to test
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Hello again 11ford11,
Thanks for your suggestions....
Pulling the 60A glow plug fuse does not remove +12V from the Ignition Relay (2nd one down on the LHS), however pulling the 60A Ignition Relay fuse does indeed remove the +12V from the Ignition Relay socket contact.
That leaves me wondering what the function of the Ignition Relay is, and also whether there is still a separate Glow Plug relay that is yet to be discovered.
With the Ignition Relay withdrawn, I bridged the two socket contacts (the fat ones) and measured both the bridging current and the battery current:
Bridging current = 0.3 Amps
Battery current = 3.0 Amps
When bridged, another relay can easily be heard operating on the other side of the engine (I can't actually identify where it is). It is quite a loud 'clunk'. And this is presumably what is pulling most of the 3 Amps.
Interestingly, when the car's ignition is switched on to the position where the glow plugs should be powered, this same loud relay does not operate. However, at the same time, the Ignition Relay gets 12 Volts to its coil circuit. That is confusing!
Unfortunately I can't even see (with a mirror and torch) the wiring to the glow plugs - let alone find, or put a meter on the wiring.
Also of interest, is that the resistance to earth of the non-hot socket contact for the Ignition Relay is 10k Ohms - not what I would have expected if that contact was connected to the four glow plugs in parallel.
I am fresh out of ideas now......