Battery drain

After a battery replacement I still appear to be getting battery drain. What I have discovered is that there’s an aftermarket button I need to press to warm the glow plugs which seems to run directly from the battery terminal. Even with the ignition off and the isolator switch active the glow plug warmer still lights up when pressed indicating its constantly live. So two questions, on a 300 tdi engine on a 1990 defender 90 do I need to heat the glow plugs to help starting? Can I connect to a live source other than direct to the battery or is there a high load on the glow plug heater? Thanks

They do take a lot of current. You should have two relays both of which are timed. The first is in the cab and energises the light on the dash and feeds the second which is on the bulkhead in the engine bay.
The heavy duty relay in the engine bay is connected to the main feed and the heater plug rail.
This relay is behind the heater hoses in the pic below.



The main fuses are below in that black box - I think the heater plugs need a 40 or 60Amp fuse (??)
If you turn on the ignition the orange glow light should illuminate in the dash and then goi off after around 10 seconds. If you wait you will hear the second relay click off after another 10 seconds.

The engine will start without glow plugs but you need a good battery and warm weather. The glow plugs do help and are likely neccesary in the winter.
I have a 94 and a 95 both seemed to labour when starting a couple of years ago and I changed the glow plugs.
As soon as the dash light goes out I turn the key the 94 starts almost instantly. The battery in the 95 is a bit weaker so I wait until I hear the "clunk" of the second relay and it starts first go.

Which model is your landy ? Is it a Defender [ 200 tdi original engine ] ? Or the previous turbo diesel model [ 19j original engine. ] ? If original front grill the first will have " Defender " on it . If second it will have "Ninety " on it. Makes a difference on how glow plugs set up.

@tottot, what's the difference between the TD and TDi engine glow plug wiring set-up...TD no timer relay, 200tdi with 6pin glow plug relay[single relay] ?

I ask as my Ninety had a 200tdi conversion completed many years ago with glow plugs running of the ignition. I've recently fitted the 6pin timer relay and am having issues with 12v constantly on to glow plugs, no glow plug light on dash.

The TD set up has a heavy duty ignition switch set up similar to NA and series 3 models before.
The switch has large connectors/contacts to carry the power direct from the battery through the switch [ no relay ] to the plugs and is activated by holding the switch at the point just before where the starter is activated [ glow plug light comes on in the dash, actually a choke symbol as LR never bothered to update it.] My Ninety TD [ been 200 tdi for a dozen years now] still uses the TD system. Handy at times I recon, when weather hot just start and when cold one can hold glow on for as long as you like for a better smoother start. One can even hold glow on after starting for a bit when very cold, helps motor settle into smooth running.
The tdi switch is a lighter unit that just activates the relay.

Thanks @tottot , every day's a school day. So my 1987 Ninety has the heavier ignition switch.

That is what should be fitted and there is no need to have a relay if you are happy to use the old " count the seconds " method of using the glow plugs.

tottot said:

Which model is your landy ? Is it a Defender [ 200 tdi original engine ] ? Or the previous turbo diesel model [ 19j original engine. ] ? If original front grill the first will have " Defender " on it . If second it will have "Ninety " on it. Makes a difference on how glow plugs set up.

Click to expand...

Apologies for a semi-hijack!

I have just replaced the ignition switch in my 1985 Ninety which was a 2.5 petrol now a V8. The switch is the diesel type and has the large tag for the glow plug. When testing it with a bulb probe I didn't notice any power coming from the tag when starting up....I take it it is meant to? If so I need to cover it up to prevent an accidental short but could I use it as a pulse supply for something else?
This is the switch as wired for a petrol:

Thank you.

miktdish said:

They do take a lot of current. You should have two relays both of which are timed. The first is in the cab and energises the light on the dash and feeds the second which is on the bulkhead in the engine bay.
The heavy duty relay in the engine bay is connected to the main feed and the heater plug rail.
This relay is behind the heater hoses in the pic below.

View attachment 240951

The main fuses are below in that black box - I think the heater plugs need a 40 or 60Amp fuse (??)
If you turn on the ignition the orange glow light should illuminate in the dash and then goi off after around 10 seconds. If you wait you will hear the second relay click off after another 10 seconds.

The engine will start without glow plugs but you need a good battery and warm weather. The glow plugs do help and are likely neccesary in the winter.
I have a 94 and a 95 both seemed to labour when starting a couple of years ago and I changed the glow plugs.
As soon as the dash light goes out I turn the key the 94 starts almost instantly. The battery in the 95 is a bit weaker so I wait until I hear the "clunk" of the second relay and it starts first go.

Click to expand...

Thanks really helpful, I don't have a glow plug heater light on the dash just this light fitted that I have to press and hold on the dash which is permanently able to draw power from the battery irrespective if the ignition is on or not

The plug output tag should be live only when key is held in glow position or starter is being activated and would only work if there is a live feed to the other large tag.

tottot said:

The plug output tag should be live only when key is held in glow position or starter is being activated and would only work if there is a live feed to the other large tag.

Click to expand...

Thanks. Just to confirm, the main brown 12V feed is on tag #5, so tag #2 will be live as long as I hold against the spring or turn fully to start?
If yes, then can I use that as an ignition supply source for the immobiliser i.e. when armed any 'illegal' starting will trigger the alarm?
Cheers.

I recon so if that is what is needed to trigger alarm.

My old 2.5NA D had the manual ignition switch and that required 5-10-seconds in mild weather and 15-20 seconds in the winter otherwise you were wasting your time. That said, as long as you pre-heated it then started on the button and ran perfectly (when it failed to catch immediately I diagnosed a faulty glow-plug which, when replaced returned everything back to normal). The only problem with that set-up was that my wife struggled to hold the little key against the spring and would often try to start it without the correct amount have pre-heating taken place (which was never going to work).
My 300TDi has always been a good starter, is a good today as it was when new. Most of the time no pre-heating is required at all but in the winter I do tend to let it heat for a couple of seconds but even then it starts with no fuss, excess smoke or uneven running. I occasionally let it pre-heat just to ensure the replays are still operating but that is it (the dash light goes out a couple of seconds before the heater relay cuts out, if you listen hard you can hear it click and also see the voltmeter move).