While this information is out there in a variety of threads on different boards, I thought I would provide a write up on what I did with my '95 DI today when the Lucas 17VT Alarm ECU began acting up.

What was happening with the Alarm ECU is, suddenly, it would not allow the truck to turn over. It would just crank.

This led to a bit of research about bypassing the Alarm ECU on 14CUX 3.9L/4.2L 1994 and 1995 DI's/RRC's. I know all about bypassing the green Lucas 10AS alarm ECU in GEMS trucks. I did that to get through last winter with a '96 DI beater but this was an entirely different ECU. A quick read of Discoweb turned up one particular thread where PT Schram mentioned an easy way to bypass the Lucas 17VT Alarm ECU. Essentially, unplug everything and the truck will still work fine. Well, that turned out to be a little too optimistic. Another comment indicated that you needed to ground the #1 pin on the white multi pin connector that goes into the Alarm ECU. With that, the neutral safety switch on the transmission is grounded and the truck will turn over. You lose the central locking and the horn but the truck will run.

The #1 pin has a Black/Orange wire running into it. At least that's the case on my '95 DI. I installed a plug into the #1 connector and routed that wire to the outer passenger footwell where there is already a ground. With the neutral safety switch properly grounded, the truck fired up on first crank. Overall time to do the bypass was well under an hour and I no longer have to worry about the truck not started because of a 21 year old alarm box. The next step is to examine what needs to be done to restore the central locking and the horn. I short time with the '95 DI ETM should provide the necessary infor to help with restoring those features.

In the end, this is yet another reason why my favorite DI's are these '94's and '95's. Their simplicity makes problem solving electrical issues such as this one a breeze compared to later Discovery models. I'm just sorry that winters have taken their toll on these trucks here in the northeast and it's getting harder and harder to find models that aren't rusting away.

 

Thanks Paul! Post back if you resolve the central locks and horn, I'll likely do this on my '95.

 

yes ...thanks....watching this too !

 

Good info Paul, this should be a sticky.

 

I did this years ago on my 95 d1 when the ecu filled with water.
I purchased a basic alarm with remote start from a local custom shop.
All I hooked up was the remote start and the central locks.
The door lock actuators are wired in parellel, They are just a motor using 2 wires where power/ground is supplied on either side to lock or unlock it.
All the actuators are 2 wire EXCEPT the driver door. This one has 4 or 5 wires, the 2/3 extra wires are for a lock/unlock micro switch and micro switch ground.
Land Rover only used the unlock portion of the micro switch.
The new alarm system may need both the lock and unlock circuit so you may need to find and alter the micro switch ground and find the 5th wire from the actuator
or add one for locks to work properly. (it all depends on the alarm you are using and how it is wired)
You can pick the circuit up at the ecu connector C274, or at connector C502 (13 pin white connector) behind the drivers footwell trim panel. the ground
I did all my work at the drivers side footwell. I think I did this because some of the wires I needed did not go back to connector C274. IIRC

Connector References

behind drivers footwell trim panel

C502/4 orange -actuator motor
C502/5 pink -actuator motor
C502/6 yellow/pink -actuator micro switch unlock

at actuator
C507/3 black ground -actuator micro switch to ground
C507/4 actuator micro switch lock (may or may not have wire run to connector c502)

 

Interesting. I wouldn't mind remote start and a longer range remote when/if mine goes out. I don't see a need to fiddle with it just yet.

 

Paul helped me out off-line but for those that are using this for their own alarm issue.. I have a 95' Disco, the alarm is located on a bracket holding 4 or 5 relays and drops down on the passenger footwell side.

This is what I did on mine:

1.Cut black and orange wires on pin 1 and 2 long enough so I could reattach them later if need. Soldered the two wires together.

2. Followed these instructions on bypassing the neutral safety switch.

Neutral Safety Switch Bypass - DiscoWeb Message Boards

Everything works except the alarm and the central locking. The horn is functional.

Tex

 

another great sticky that wont make it

 

I guess I don't understand??

 

all the good tech pieces used to get put in the tech section ie. be made a sticky, that way the post could be found easily when needed.