one more little issue to sort out -any knowledgeable people out there?

harrylime · August 27, 2021

I'm just putting my 99 LS 400 back on the road having been off road since Covid arrived. I've had a few issues to sort out and have decided never to take a car off the road over winter again, they just don't like it. While it was off the road though, having moved my compressor to my new house I treated the underside with Dinitrol, which seems to be one of the better products out there. It has certainly protected my Lancia well since 1975. I've had a new alternator fitted, and the power steering pump rebuilt with new seals (the cause of the alternator issue). At 72000 miles, I'm not sure if the lay up caused the problem. The day before the MOT was due, I found that two of my newish tyres had slow punctures, so that meant running around to get them sorted out. All now well, and the car flew through the MOT, and was treated to a full service with new filters, all genuine Lexus, as usual, and had the brake fluid replaced.

The only slight niggle I have is an intermittent parasitic Battery drain. Having done some tests, the draw is greatly reduced when I remove the fuse MPX-B fuse and Radio No 1 fuse. . If I had more knowledge that information may even be useful to me. I was hoping to do some simple checking myself. I intend to remove every component I can see and clean the contacts with electrical cleaner. I will probably end up taking it to an auto electrician although, unlike most work on a car, the cost of auto electrical work, understandably, tends to be open ended without even an estimate to go on.

I have two questions:

1. Based on the circuits mentioned, are there any "usual suspects" I should look at?

2. Does anyone know where I can get hold of a wiring diagram for a 99 LS400 without too much expenditure? I bought a repair manual on CD but there are no wiring diagrams. It may help me, or at the very least, help my auto electrician. Strangely, the driver's handbook for my 1975 Lancia includes a wiring diagram, which tells you all you need to know about Lancia electrical systems and how good they are.

It would be nice to get this last little issue sorted out, so any help would be appreciated.

Tulpen · August 27, 2021

I had a drain on my 460 which resulted in 2 free replacement batteries. After the second Battery, the garage decided to do a full electrical check. It turned out to be a tracking device fitted by a previous owner. It, apparently, came with 2 years free subscription but wasn't renewed.

So, it just sat there, connected directly to the Battery, slowly draining power. It wasn't noticeable till the car sat for 2 weeks or more. By that time the Battery was flat.

Who knows what was fitted to your car before you owned it. It might be an idea to cough up the cash to have a really good auto-electrician look at it.

cruisermark · August 27, 2021

I had this problem in my Mark 4 - it was the phone in the armrest - which I removed.

dublet · August 27, 2021

Is this what you're after? https://www.ebay.co.uk/itm/163321342131

Malc · August 27, 2021

2 hours ago, Tulpen said:

It might be an idea to cough up the cash to have a really good auto-electrician look at it.

and finding one might be as impossibly draining as finding " hens teeth " :unsure:

Malc

Tinonline · August 27, 2021

Annoying…how old is the Battery and what make?

Could be a circuit left open but I doubt it…good to make sure boot light is out when shut.

Turn it off and on…disconnect battery: wait 20 mins reconnect and do usual Lexus dance and procedure…this will reset systems and ecu.

🧐

steve2006 · August 27, 2021

Hugh I have the official electrical manual for the 2000 model which is the same as 1999, you can borrow it from me if you wish.

Happy to post it to you at your expense then return it when you have done with it or you can collect and return.

steve2006 · August 27, 2021

Bit of research, the MPX-B fuse supplies the Body ECU, all the door ECUs, Airbag sensor system and tilt and telescopic steering ECU.

Radio No 1 supplies the electric aerial control relay and all of the audio system components.

Have you tried pulling out the 15A TEL fuse which partly supplies the now obsolete in car phone system?

MLW · August 27, 2021

8 hours ago, Tulpen said:

I had a drain on my 460 which resulted in 2 free replacement batteries. After the second battery, the garage decided to do a full electrical check. It turned out to be a tracking device fitted by a previous owner. It, apparently, came with 2 years free subscription but wasn't renewed.

So, it just sat there, connected directly to the battery, slowly draining power. It wasn't noticeable till the car sat for 2 weeks or more. By that time the battery was flat.

Who knows what was fitted to your car before you owned it. It might be an idea to cough up the cash to have a really good auto-electrician look at it.

That is interesting. My LS430 has an old tracker but I never used it because of the high subscription cost and the car's age were never were worth it. It has always used a steering lock from America. 3 feet of steel is a statement!.
However, the Battery has a 14-21 day life and that is on a Yuasa 5 year new Battery.

I assumed it was the security system draining, but this has got me thinking.

How to disable the tracker??

Help please?

Tulpen · August 28, 2021

10 hours ago, MLW said:

How to disable the tracker??

The garage who found the drain said that the tracker had been fitted in such a way that it was difficult to find. If you think about it, it needs to be.

I'm sorry I can't be any more specific than that.

steve2006 · August 28, 2021

First question is do you know the location of the tracker?

Once found it should just be a case of disconnecting the 12 volt supply to it or if it has a multi connector pull the plug out, as far as I know they are not interfaced with other car systems so pulling the plug shouldn’t have any affect on anything else.

harrylime · August 28, 2021

19 hours ago, steve2006 said:

Hugh I have the official electrical manual for the 2000 model which is the same as 1999, you can borrow it from me if you wish.

Happy to post it to you at your expense then return it when you have done with it or you can collect and return.

Steve

That's incredibly kind. If you could post it, I can scan what I need and return it . I will, of course, cover all costs. I will pm you my details, many thanks Hugh

harrylime · August 28, 2021

19 hours ago, steve2006 said:

Bit of research, the MPX-B fuse supplies the Body ECU, all the door ECUs, Airbag sensor system and tilt and telescopic steering ECU.

Radio No 1 supplies the electric aerial control relay and all of the audio system components.

Have you tried pulling out the 15A TEL fuse which partly supplies the now obsolete in car phone system?

I have tried the TEL fuse, Steve, it made no difference

harrylime · August 28, 2021

19 hours ago, steve2006 said:

Hugh I have the official electrical manual for the 2000 model which is the same as 1999, you can borrow it from me if you wish.

Happy to post it to you at your expense then return it when you have done with it or you can collect and return.

Steve

That's incredibly kind. If you could post it, I can scan what I need and return it . I will, of course, cover all costs. I will pm you my details, many thanks Hugh

harrylime · August 28, 2021

I'm not aware of a tracker being fitted. I would like to try to simulate the bonnet being closed when shutting the systems down How do you jam the bonnet catch, it's on a hell of a strong spring?

steve2006 · August 28, 2021

3 hours ago, harrylime said:

I'm not aware of a tracker being fitted. I would like to try to simulate the bonnet being closed when shutting the systems down How do you jam the bonnet catch, it's on a hell of a strong spring?

A big screwdriver normally works or take the wires off the bonnet switch and connect them together.

MLW · September 16, 2021

My 430 again failed to start and the Battery was very very flat. There must be a drain down somewhere.

On a tracker, will it eventually be wired in to the fuse box? Will it then be a case of finding it and taking out the fuse. Will it affect anything else.