Electrical/Starting Woes

[Richard Jackaman]

I've been having some issues starting my 80 in the past few weeks even though it's had two new batteries in the last 6 months, both 95A/h Bosch ones.

After removing them both from the truck and charging for 24 hours each,the vehicle still won't start if left for more than a couple of days and needs to be jumped.

I've checked the following:

- Voltage across the batteries rises to about 14.4V when the truck is running so I assume that the alternator is charging them.

- Using an ammeter I checked the current drain when the vehicle was stopped and it was showing 400mA but I don't know if this is a lot.

- Removing the fuses one by one dropped that to 150mA when the seat motor fuse was out, again not sure if this is normal or not.

- Drivers side battery drops to around 4V whilst the passenger side one is up at 10 - 11V when I attempt to start the truck.

To me it looks like the drivers side battery is faulty but if anybody has any thoughts on the matter I'd like to hear.

 

[frank rabbets]

You most likely have a bad battery. 400 ma would not drain the battery so quickly. Dropping to 4volt points to that battery being dud unless you can smell burning from somewhere. Exactly the same thing happened to my 80 with a 12 month old battery which was replaced foc. I've had three battery failures now on my 80 and it has always been the drivers side. I think this side supplies the inlet heater which stays on for a couple of minutes or so after you start the engine. That's why the voltmeter suddenly shoots up after said period has elapsed and the heater kicks out.
On another car I bought a Bosh top of the rage battery which failed after 6 weeks !!

Frank

 

[Jon Wildsmith]

400mA drain is huge, you sure there wasn't a courtesy light on? 150mA is still big but will take longer than overnight ... 4V is a failed battery, assuming you're checking at the battery terminals.

 

[Dave]

400mA is a big load. A 95AH battery will deliver 95 amps for one hour, or 1 amp for 95 hours. So with a half amp load it will last for 190 hours, or 8 days (at best).

 

[Richard Jackaman]

Checked at the terminals Jon.

I didn't know what a typical drain was for a LC. Draw was 1.2A when I had a door open (all door lights on). I wonder if there's an issue with the seat motor circuit as that was drawing 250mA when everything was off.

I'll get the battery replaced at the start of the week as it's still under warranty.

 

[joinerman]

Never been a lover of Bosch batteries, had two on my other car ( BMW 530d sport ) in twelve months, first replaced foc second one they wouldn't wear it said it was a fault with the car, bought a Youasa no more trouble !!!!

 

[Towpack]

I had a similar fault on my 24 valve 80 which turned out to be a faulty intake heater relay giving a permanent 350ma current draw even with the vehicle parked up. This was enough to flatten the (good) batteries enough over 5-6 days to prevent starting. When fixed the normal current draw was @30ma with the car locked up and alarm set.

 

[Richard Jackaman]

Pardon the thread resurrection but it was mine originally and I think I've finally got round to fixing the problem.

After getting the batteries replaced for a second time foc I thought I should get to the bottom of the issue having put it off for a couple of years hoping it would go away

Anyway I removed the batteries,and the battery tray on the drivers side and found this.




The inlet heater relay sits directly under the battery tray just where the drain hole for any water exits so gets wet when there is any water draining.

I connected up a clamp ammeter and measured the drain with this relay in place and was getting aroung 400mA and in the couple of minutes of testing the relay was getting hot to touch.

Removing the relay and insulting the terminals and the drain drops dramatically to 3mA or so. Much better.



Relay cover, totally burnt out.



Relay after removing from truck.

The question I have is do I need to replace the relay and if so is there a cheaper option than Mr T?

I seem to remember somebody used a motorcycle relay as a replacement but don't recall the details.
Would I do any damage by not replacing and therefor not having a heater on the inlet manifold?

Any thought?

Cheers

Richard

 

[Chris]

I don't recall ever having seen one of those on mine. I think you may have found the source of the problem though Richard. Yep. That'd be it.

I'm going to have a rummage under the bonnet.

 

[Richard Jackaman]

Wouldn't want your truck to catch fire..........................again!!

 

[Chris]

Stop it.

 

[Richard Jackaman]

Sorry

 

[Shayne]

Seeing the title of the thread i thought i may be able to add something useful as i've had a similar problem with my boat which has been a bugger to start (Nanni N4.115 turbo diesels which are basically marine Kubota) everything else had been ruled out so i went order new glow plugs and the supplier said "no , the engines are only 3 years old check the electrical connection just beneath the alternator" happy days he saved me a few hundred quid and is even sending me a new connector free of charge - hows that for service

Was just gonna say is power getting to the glow plugs , but obviously the question has been answered .

 

[Jon Wildsmith]

I disconnected the heater and removed the relay on mine not long after I got it, to make sure it couldn't cause problems. Haven't had any trouble starting it but I don't think it's been below about -5.

 

[Chris]

I have been for a squirm around in the dark and can't see any evidence of this on mine. Now, I am pretty sure that the heater connection has been disconnected (plug on the side of the manifold near the EGR valves sort of thing?) and there are a fair few loose plugs hanging around too. Mine is a GS so even air in the tyres was a factory option. It may be that someone has already removed the unit. I'll have the tray out at the weekend though. Not the first time I have heard of this issue but then I didn't have a 24v back then.

 

[Towpack]

Pardon the thread resurrection but it was mine originally and I think I've finally got round to fixing the problem.

After getting the batteries replaced for a second time foc I thought I should get to the bottom of the issue having put it off for a couple of years hoping it would go away

Anyway I removed the batteries,and the battery tray on the drivers side and found this.




The inlet heater relay sits directly under the battery tray just where the drain hole for any water exits so gets wet when there is any water draining.

I connected up a clamp ammeter and measured the drain with this relay in place and was getting aroung 400mA and in the couple of minutes of testing the relay was getting hot to touch.

Removing the relay and insulting the terminals and the drain drops dramatically to 3mA or so. Much better.



Relay cover, totally burnt out.



Relay after removing from truck.

The question I have is do I need to replace the relay and if so is there a cheaper option than Mr T?

I seem to remember somebody used a motorcycle relay as a replacement but don't recall the details.
Would I do any damage by not replacing and therefor not having a heater on the inlet manifold?

Any thought?

Cheers

Richard

Yep, just what I found in my case. Apparently there was a recall years ago for this problem after some almost caught fire? An OE relay is around £180+Vat IIRC. I replaced and resited it with a motorcycle starter relay for around £15.

 

[Richard Jackaman]

I wonder if the recall still applies?

 

[frank rabbets]

My1995 was recalled in about 2000. Isn't one of the relay wires live all the time meaning that current could short to earth all the time. So even if the inlet manifold is disconnected a fire could occur?

 

[Towpack]

The feed side of the relay is connected directly to the battery so will be live all the time. The battery drain problem problem occurs when the relay corrodes. Corrosion bridges the contacts and flows current to the heater unit all the time. Wether this is the cause of the relay meltdown I'm not sure. The heater pulls around 50amps so it's quite a load. Maybe the relay wasn't up to the job in the first place and the contacts run hot? Either way, personally, I can't see Toyota honouring a recall on a vehicle that ceased production almost 17 years ago but you could always ask.

 

[Richard Jackaman]

To be honest it's not worth the effort. It would cost me more in fuel and time even if Mr T would honour the recall than it would to replace with a motorcycle relay.

The problem is indeed corrosion. The relay sits under the drain hole in the battery tray. Mine was so corroded than the bracket had disintegrated so even if I replace it I might try and relocate it.


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