glo plug warning light problem

I have a 1985 land rover 110 to which I fitted a 300tdi engine in place of the n/a engine. Needless to say, greatly improved performance. The glo plugs were heated in the same way as original, by turning the ign on, and then turning a little further against the spring loading, when the glo plug warning light would come on. I would hold for several seconds and then complete the starting process by fully turning the ign key to operate the starter.

I have just finished fitting a s/h td5 dash instrument pack, using the original clocks, but changing all the wiring to the warning light panel as in this web page: http://www.retroanaconda.com/landrover/2009/10/installing-defender-td5-gauges-into-a-200tdi300tdi/

All the lights seem to work ok, except the glo plug light. When I switch on the ign the oil and battery lights come on as normal, but so does the glo plug light, which then goes out when I move the key to the plug heating position – a reverse of what it should do. However, the glo plugs work as they should, with power going to them when I turn the switch to glo plug position.

I have never had a timer or relay fitted, and the thick brown and red cable runs direct from the ign switch to the glo plugs, and the thin brown and red cable connects into the warning light panel, as it did before the change.

Does anyone have any idea where I’ve gone wrong.

Suicidal is a word that springs to mind!!

It may just be down to how the different warning panels work, your original one probably got a +12v feed to the glowplug light bulb when the glowplugs where being powered (positive seeking), from memory the TD5 dash glowlight circuit is normally fed from the glowplug relay, there is a possibility that the relay sends out a switched ground (negative seeking) to put the light on. Like I say, just a guess without a lot deeper look

Is there power to the plugs when light is on and does it go out after a few seconds on its own. You may not need to use key to power plugs and leave it on auto, all depends on checking the above first.

Gmacz said:

Is there power to the plugs when light is on and does it go out after a few seconds on its own. You may not need to use key to power plugs and leave it on auto, all depends on checking the above first.

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Thanks Gmacz. No power to the plugs when the light is on, and it's manual, unlike 300tdi that has relay
Kwakerman, are you suggesting that I change the wiring to include a relay/timer as in the td5?

Do you need glowplug light on, just pull bulb and continue with key operating plugs.
Saves all the hassle and job is done.

Gmacz said:

Do you need glowplug light on, just pull bulb and continue with key operating plugs.
Saves all the hassle and job is done.

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That would certainly sort the problem. Still want to know why it's happening though! Thanks for that.

the small brown/red going to cold start glow plug lamp is correct but the wire on the other side of the lamp would have been grounded earthed via the glow plug timer
so you will have to connect this wire to earth /ground I think it colour was yellow /white but check before doing any connections

the glow plug grounding /earth wire should be black/yellow

I fitted td5 dash clocks/light panel to my 300 bitsa I've brought the bits to fit a glowplug timer relay to make it all work as it should. Isn't hard to fit and saves wearing out your ignition switch. You don't really need the plugs on a 300 anyway unless it's really really cold. Mine starts at below 0 without them they bits to fit it properly only cost like 50 - quid relay and various cables
and the warning light cable on standard diagram is a yellow and black I think switched ground from the relay.

harrierpilot said:

Thanks Gmacz. No power to the plugs when the light is on, and it's manual, unlike 300tdi that has relay
Kwakerman, are you suggesting that I change the wiring to include a relay/timer as in the td5?

Click to expand...

From the other discussions it does sound like the glowplug wiring is operating in the wrong sense (you need a switched earth rather than a switched +12). If that is the case then you either need to.
1. Reverse the operating sense of the glowplug light wire (using a relay or similar)
2. Fit the 300 glowplug relay and wire up as per 300.
3. Live without the light.

TURBO AND NONE TURBO GLOW PLUG TIMER AND NO TIMER LITTLE WIRING REQUIRED

Might help