Where is my electricity going?!

[Gregh]

I wonder if anyone can help concerning a strange current drain on my 1996 80 series?
Last weekend I woke all my neighbours up in the early morning when the alarm triggered on it's backup battery because the batteries had gone flat, and really FLAT, as in 650mV.
I recharged the batteries and re-connected, all appears OK except there is a 200mA drain with everything off.
I see on the forum that others only have 30mA drain when off so I think I have a problem.
Disconnected the Alarm, Radio, Electric Aerial and phone charger, everything that I have fitted, and I have 150mA drain.
Pulled ALL the fuses but this drain remains.
Seems unlikely that 200mA would flatten the batteries in the two days that I did not use the car and I can only assume that because I was driving for two days previously with headlights due to the bad weather I must have reduced the charge on the batteries and this drain was enough to flatten them in two days.
Batteries are 4 months old.
Got them tested once charged and both came up as good.
Alternator puts 14.5 Volts on them on tick over but drops to 14 volts with the lights on.
I am stumped now.
Anyone got any ideas?
Regards
Greg

 

[Towpack]

I had a draining battery problem a couple of years ago which turned out to be the engine air intake heater relay. I'm assuming your '96 car has the same 1HD-FT engine which has this heater instead of glow plugs. The relay sits under the offside battery tray and has a large cable feed direct to the battery. The relay on mine had actually stopped operating but had gone partial short circuit across the feed and load terminals, probably due to corrosion, and the heating element was pulling around 350ma all the time. The relay had obviously been getting very hot in the past 'cos the cover was melted. I replaced it with a motorcycle starter relay for around £15 (the OE Toyota part is £180+ IIRC) but the engine starts easily without it on even the coldest mornings so could have left it off. I like to use it on very cold morning starts as it helps prevent oil dilution.

Try disconnecting the power lead on the heater and see if the battery draw disappears.

 

[Gregh]

I do remember pulling a fuse for "Fuel Heater", wonder if this would be on that circuit.
I will definately check this out however.
Thanks for the tip

 

[Towpack]

The fuel heater and air heater are seperate. The air heater pulls around 40-50 amps when in use so does not go through the fuse box.

 

[frank rabbets]

Your heater relay defo needs checking whatever as they have caused fires in the past. Mine was recalled and a different type fitted. Mine's a 1995.

Frank

 

[Gregh]

Definately getting a burning smell from around the front offside wheel.
I have smelt this months ago and thought it was my imagination but it was confirmed by a friend of mine yesterday.
The Landcruiser's in for AC repairs today and as soon as it's back I am locating this relay and checking things out, (assuming it hasn't burst into flames at the AC repairers!).
Will return with an update.
Thanks for your help guys, very much appreciated.
Greg

 

[Gregh]

I had a draining battery problem a couple of years ago which turned out to be the engine air intake heater relay. I'm assuming your '96 car has the same 1HD-FT engine which has this heater instead of glow plugs. The relay sits under the offside battery tray and has a large cable feed direct to the battery. The relay on mine had actually stopped operating but had gone partial short circuit across the feed and load terminals, probably due to corrosion, and the heating element was pulling around 350ma all the time. The relay had obviously been getting very hot in the past 'cos the cover was melted. I replaced it with a motorcycle starter relay for around £15 (the OE Toyota part is £180+ IIRC) but the engine starts easily without it on even the coldest mornings so could have left it off. I like to use it on very cold morning starts as it helps prevent oil dilution.

Try disconnecting the power lead on the heater and see if the battery draw disappears.

Towpack you are a Star!
Removed the Battery and tray and followed the burning smell and there was the sorry looking relay just as you said.
It was well on it's way and most likely would have ended up burning or blowing something.
I am going to have to replace the feed cable as well as the terminal was completly finished.
Funny arrangement on the supply cable though.
There is a second White cable, about 250mm long jointed onto the main feed cable and heat shrink sheathed.
Wonder why Toyota did this? Looks like an afterthought to beef up the cable but only at the relay connection end.
You would think they would just use a bigger cable as it's less than a meter long in total.
Attached some pics.
I do not wish to spend £180.00+ so it's a motorcycle starter relay that I will be looking for if I cannot find a second hand part!
Thanks for your help Towpack.

 

[Towpack]

Great, glad you found it. Can't quite remember if mine had 2 cables like yours but I also had to renew as the terminals were shot. Your relay looks exactly like mine did. As Frank has already mentioned, some were recalled for this but some obviously slipped through the net although mine is a '98 reg ('97 build) so you would expect it to have the updated relay and wiring from new?

 

[frank rabbets]

So why the current drain as the relay should be off with the ign key out?

Frank

 

[Gregh]

The current drain has gone from 200mA down to 80mA, with the Alarm connected, now that the relay is removed.
I think this is similar to what jon Wildsmith said was the reading on his vehicle.
When I got to the relay it was soaking wet.
The actual location must be near some drain route from the front and battery tray areas and I wonder if this is what starts the problem.
The terminals being around 10mm apart and immersed in the water that lays under the plastic cover of the relay are maybe conducting a few mA through the water. Then throw in a bit of general engine compartment dirt and a helping of road salts and you could get a nice slow elctrolysis that breaks down the mechanical connections over time.
Just a theory of course.
Mine is a 1996 Registered, built in Feb 1995, so maybe the cable construction was an interim "patch".
I will have a heavy duty feed cable made up as replacement when I find a replacement part.
As Towpack says it does not appear to make any difference to the starting at the moment.
I wonder if I will notice if we have a hard winter this year.

Greg

 

[frank rabbets]

I've permanently disconnected my air intake heater by simply removing the cable off the terminal on the heater. I did this because I do many short journeys and almost every time I start the engine, even when warm, the heater is connected drawing a large current and stressing the battery/ies. It took some time for the voltmeter to read full charge and some times did not due to the short journeys. The heater may only be for emission control? Anyway I have found no difficulty starting the engine even well below zero.

FRank

 

[Towpack]

Gregh,
I agree with your theory on the relay as mine was doing the same thing giving a permanent current draw even though it was not wet externally.
When I re-fitted the replacement relay I wired in a switch under the dash so I can disable the heater if required and only use it for really cold starts. Even though the engine starts readily without it, it is beneficial to the engine, giving a more complete burn of the fuel charge on those really cold starts and reducing bore wetting. JMO