1996 LS400 - Fitting a Hawk universal remote central locking kit. Help needed please

[Howplum]

When I bought my car in 2020 I had an auto electrician disable the immobiliser, because it was proving troublesome. In the process I lost the remote central locking facility, although it stills works fine using the key.

I recently bought this Hawk kit, hoping the process of installing it would be reasonably straightforward, but it's not!

Although Hawk's instructions state the crucial lock (green/red) and unlock (green/black) wires are behind the right side kick panel, they are not. I have disconnected each plug individually and the central locking still works.  On US websites the wires are apparently attached to the ECU inside the front passenger (right?) door.

Behind the left side kick panel there are three plugs, the bottom one seeming to include the wires I'm looking for, since disconnecting it disables the central locking. Unfortunately the wiring diagram I have in an electronic (US) Repair Manual does not help, because what I need is presumably a pinout diagram of the bottom plug.

I spoke to Hawk but they couldn't clarify the anomaly for me.

I did notice that a couple of wiring piggy backs have been cut on the top plug, which perhaps are for the hazard lights, although disconnecting the plug only disables the rear hazard light with the dashboard warning lights still flashing at normal speed.

The kit includes a wire for the boot release, and although I bought a recommended relay, I'm not sure I need it since the wiring is already in place. Presumably I just attach the wire to whichever is the output wire on the dashboard switch.

The other wire included is for the window closure system, but I don't know where to start with that one.

Any help would be appreciated. Thanks.

 

 

 

[steve2006]

I managed to fit one to my 1994 Celsior, again not easy but I did manage to do it including the remote boot release.

Another member with a 1994 UK spec model also bought one but the wiring was completely different even tracing back to the door switches so after several hours it was a no fit.

It is still in my garage, not mine so stays there.

The trunk release doesn’t need a relay as there is a factory one.

The remote keys were a bit flimsy with the rubber key ring bit splitting soon after purchase.

[Howplum]

Thanks for your response Steve. If you found it less than easy then I should probably admit defeat now!

[Razor61]

On 7/11/2022 at 9:55 PM, Howplum said:

Thanks for your response Steve. If you found it less than easy then I should probably admit defeat now!

Do you have a workshop manual with the Body+Electrical section?

[Howplum]

Paul, I have a 2,220 page "Lexus LS400 1995-2000 Repair Manual" which I bought on a CD and have downloaded onto my laptop, but I don't have the pukka workshop manual. 

It does contain many wiring diagrams, but finding anything can be a challenge at times. It doesn't seem to include pinout diagrams for the various connectors.

Having established that removal of the bottom connector on the A pillar disables the central locking, I would either need a pinout diagram or some way of testing each individual wire. Apparently the central locking is a negative based system, whatever that means. I assume that turning the door key to activate the C/L sends a pulse, so presumably any testing has to be done with someone else operating the door key, or the button on the driver's door.

Another assumption of mine is that any aftermarket system is spliced into the existing lock and unlock wiring to the door locks, thus overriding the factory system. In theory fairly straightforward, the sticking point being finding the elusive two wires that carry the lock and unlock signal. In an ideal world a specific wiring diagram for the door locks system applying to my car, manufactured in April 1995, would be extremely useful.

Apparently there is a "Receiver, door control" (89741-50210) located somewhere in the upper area behind the left hand side of the dash. This has only 4 wires: 12v from dome light fuse (+B), ground (GRD) and two wires marked RDA and RCO which go to the Body ECU. Another assumption of mine is that this unit receives the wireless signal from the remote and transmits it to the Body ECU. This might be a red herring though, since I won't be using the original remote fob.

As you can probably tell I'm no electrician, so any guidance would be appreciated.

I have left a message with the electrician who disabled the immobiliser and remote system to see if he can help.

[Malc]

8 minutes ago, Howplum said:

I have left a message with the electrician who disabled the immobiliser and remote system to see if he can help.

when I contacted a local and renowned auto electrician about my Ls400 he did me the courtesy of simply just ignoring me ........  as did others ...  apart from one ordinary auto guy that also did electricals and he advised me that he just didn't know what on earth he could do to help me

I have a strong feeling that these " experts " in many instances just really haven't a clue 

Hope you have much better luck than me for sure

Malc

[Howplum]

It seems as though there are quite a few authentic year specific repair manuals on the US eBay, albeit at a price! About £200.

Maybe I should bite the bullet. In my opinion there's no substitute for thumbing through a book and discovering little gems of information, or even the answer sought.

 

[BigBoomer]

The problem with modern car "electrics" is that they aren't electrics.
They are computerised, networked (CANBUS), very complex systems that rely on both software and hardware and your average car "electrician" simply does not have a clue how they work. In my experience even the so called "specialists" at the dealers and independents only know enough to narrow the problem down to which black-box is failing, and then replace that box. That black-box switches relays on and off according to what the software tells it to do and according to network communication with the other black-boxes.
There are a few super-specialists that know almost all of it, but they are rare and very expensive.

I'm reminds of when my Dad was sent to a customer site in the early 80's to troubleshoot a Nuclear Power Station control system simulator (for training Power Station operators). It took him 2 days to troubleshoot the problem with the mainframe computer down to a single cabinet, so he told them to replace that cabinet. They asked why he didn't troubleshoot it down to board or component level, so he informed them that so far they had paid £5,000 for 2 days of his time and it would take another 10 days (£25,000) to troubleshoot to component level,... or they could pay £5,000 to replace the entire cabinet. They chose to replace the cabinet and it fixed the problem. 🤣

You may be able to disconnect the final control wires (that come from those relays) and replace them with other systems, but beware as sometimes there are sensors that feedback data to the computers that also need to be fooled into reporting that it is all working as it should.

[Malc]

so basically .  probably, no one's got a clue  

Malc

[Howplum]

To be fair to the auto electrician he didn't seem phased at all and just got on with the job. He charged me £45, so it probably took him less than an hour. I assumed he had access to the correct information, so hopefully he can help me add an aftermarket system. 

[steve2006]

If you want to see someone with good diagnostic skills check out “Diagnose Dan” on YouTube.

[Howplum]

I've spoken to the electrician and explained the issue, so  he will be coming to see me the week after next.  I explained I wanted a Hawk system fitted and apparently he has fitted a few and thought they were quite reliable. He did make the observation that some of the wires are a bit on the thin side so might need strategically placed relays for utmost reliability. I took this comment as a good sign. 

[Las Palmas]

22 hours ago, Howplum said:

I've spoken to the electrician and explained the issue, so  he will be coming to see me the week after next.  I explained I wanted a Hawk system fitted and apparently he has fitted a few and thought they were quite reliable. He did make the observation that some of the wires are a bit on the thin side so might need strategically placed relays for utmost reliability. I took this comment as a good sign. 

Sounds like a competent electrician.

If the car has no electronic-controlled alarm from factory; if the car unlock all doors with the metal key (without any electronic components inside it):

It can be easily remote opened with just a single actuator in the drivers door. Making the same move as you do with the key. The power to the actuator shall be taken directly from the Battery and wires of correct dimension must be supplying power to it. Only 1 door need an actuator and the electronic circuits in the car take care of opening the other doors.

[Howplum]

He's coming on August 4th, so I will watch with care and see what he does, not only to satisfy my own curiosity, but in case it helps others.

Apparently the cars did not come with a factory fitted alarm/immobiliser. These were dealer fitted in the UK, mostly using the Scorpion 5000, I think. I assume the alarm/immobiliser was activated/deactivated by the central locking.

[Malc]

19 hours ago, Howplum said:

I think. I assume the alarm/immobiliser was activated/deactivated by the central locking.

on my 1995 car the alarm that comes from the factory as fitted, is activated by / at a dial, which you can turn the sound down ( to off ! )  under the wood grain trim by the gear stick / front arm rest .....  careful as you move it tho'

The "  dial down "  removes the sound of the alarm which is often activated by a metal object whatever being in close proximity .  in the arm rest holders for instance 

This clearly is nothing to do with your personal needs for the complex Hawk Universal system however, being a retrofit upgrade to your car's security .....  so

Good Luck with it all

Malc

[runsgrateasanut]

On 7/15/2022 at 3:22 PM, Howplum said:

 He did make the observation that some of the wires are a bit on the thin side so might need strategically placed relays for utmost reliability. I took this comment as a good sign. 

Thinwall cable which has a harder PVC grade and carries a higher load than conventional Cable has been around for some time. Certainly a catalogue I'm looking at mentiions this and is dated 2005. Used to reduce weight and has better resistance to abrasion, apparantly. .