Been trying to get heater plugs to power up, with no joy as part of a Re-comissioning of Defender 90 2.5 TD , having enough probs with Fuel supplies (injection pump) , but the heater plugs not working seems to just be the tip of iceburg... So I stripped the dash and instrument out to see whats happening - nighmare some previous owner has sprinkled scots connectors, bypasses, and twisted connections liberally around the systems complete with self amalgamating tape, and domestic two core wire. The igintion heater wiring has been bypassed from the Ignition key via a dodgy push button direct to the Battery which was shorting:mad2: (no wonder it didnt work) . The radio hook up looks like my two yr old grandson could have knitted it a lot better I also found a heavy gauge white wire 10" long with bullet one end and a large spade the other unconnected at either end. Any guesses where it should be hooked up ? the white connector to the ignition switch looks occupied ...???

Ah well looks like the soldering iron , and shrink connectors are going to have to come out - planning on using the ones i use on the boat which shrink and also fill up with a hot glue mix that seem to be really good at sea- anyone with any experience in the muddy world of Landys ?

are you working on my landy ?

it sounds like my landy.....

IIRC the 2.5TD didnt have a relay on the heater circuit and was direct through the ignition so was prone to melting the ignition contacts due to the high current.

So that must be a standard sort of mod , but they way its been wired by previous owner crazy . Ive ordered new switch so will try that and then think about relay with a better button , anyone know what current rating the Relay will need to have ?

Not sure - might be 80A

PRC6913 is the part number

Is this any good:
http://www.landyzone.co.uk/lz/f55/19j-glow-plug-wiring-183504.html
I remember that I agree with the 10A

A sensible diagram that I have from a later model shows a 100A fuse to the glow plugs, 6mm cable to the relay and then 2.5mm cable to the plugs (wired in parallel).

So this implies for this model 2.5mm per plug @ 6A per 1mm the cables to the individual plugs can take 15A per plug, pretty much 10A per plug plus headroom.

If only I can find a similar diagram for my 19j - sigh

The plugs themselves should be "Glow Plug 2.5 D 2.5TD and Late 2.25 D from 10J001175 (part number ERC8450)"

Have ordered a 70 (with socket and a 100 amp relay which should cover things. I'm guessing 'ill need to visit a Nuclear powerpoint to get some cabling . Power take off for the low current side of the relay should come from where do you think?
Still got to Trace the short on the original wiring should be obvious melted wires/ sparking etc but nothing seen so far.

Take the low power from the same ignition switched White cable I suggest?

Browns should be straight from the battery, but why risk flattening the battery or over cooking the heaters if you get a short or summat?