Discovery 1 problem

hi all, I have a problem with my 98 disco 1 300tdi.
All of a sudden I have no hazards or horn. I have checked fuses & all seems ok.
Any ideas what the issue could be?

Indicators, radio, interior light work fine.
Thanks.

Craftycarper3 said:

hi all, I have a problem with my 98 disco 1 300tdi.
All of a sudden I have no hazards or horn. I have checked fuses & all seems ok.
Any ideas what the issue could be?

Indicators, radio, interior light work fine.
Thanks.

Click to expand...

Check the engine bay fuses.




Cheers

Hi thank you.
I have now checked these fuses under the bonnet & were fine.
Any other ideas?
Many thanks.

Did you check to see if they had 12V there?
Can I ask , how did you check them? with a multimeter? visual check? have you tried swapping fuse 4 for a different one?
Cheers

It was just a visual check. Yes I also tried another fuse from different location too.
Many thanks.

Do you have a feed to the fuse?

Is there any other abnormalities?

dieseldog69 said:

Do you have a feed to the fuse?

Is there any other abnormalities?

Click to expand...

Hi. I need to get the feed checked out tomorrow, the only other abnormal thing is that the immobiliser kicks in even when the engine has been turned off for only a couple of minutes with me sat inside the car.

Craftycarper3 said:

Hi. I need to get the feed checked out tomorrow, the only other abnormal thing is that the immobiliser kicks in even when the engine has been turned off for only a couple of minutes with me sat inside the car.

Click to expand...

Well, your going to be very unlucky if fuse no. 4 doesn't have an incoming 12v feed, as that has a direct connection to the battery supply into the fuse box.
Unless you have a break in the wiring only affecting both supplies for the horn relay and the hazard switch, the only other place to check is their earth connections behind the footwell kick panel.

As for the immobiliser, it's a standard feature to remobilise the engine after a short period of time after the engine is turned off, the information is in your owners handbook, unfortunately the D1s security system isn't that intelligent, and therefore doesn't know if you or any one else is sitting in the vehicle.





Sent from my iPad Air on a train

Where are you located? Might get an offer if help if you put your location up.

Discokids said:

Where are you located? Might get an offer if help if you put your location up.

Click to expand...

I am based in north wales near chester

discool said:

Well, your going to be very unlucky if fuse no. 4 doesn't have an incoming 12v feed, as that has a direct connection to the battery supply into the fuse box.
Unless you have a break in the wiring only affecting both supplies for the horn relay and the hazard switch, the only other place to check is their earth connections behind the footwell kick panel.

As for the immobiliser, it's a standard feature to remobilise the engine after a short period of time after the engine is turned off, the information is in your owners handbook, unfortunately the D1s security system isn't that intelligent, and therefore doesn't know if you or any one else is sitting in the vehicle.





Sent from my iPad Air on a train

Click to expand...

Thank you for your reply. I will check under the kick panel for any earth problems.
Strange about the immobiliser as it never used to do it, I could of left it hours unlocked & it would still start without having to demobilise it.
Only other electrical issue I have is the ignition is dodgy, it will only turn with the key facing a certain way. Strange lol

Craftycarper3 said:

I am based in north wales near chester

Click to expand...

Bit too far for me that.

Just had a thought, MFU behind the fuse board?

Perhaps @discool can verify the functions of the MFU?

I seem to remember the MFU (multi function unit) controls a lot of things including the direction lamps and horn when you set the alarm?

Happy to be corrected but you can certainly google it for yourself (too much for me to research for little to no gain for me).

I reckon the hazards and horn are wired straight from the engine bay fuse box as said above, with no other interference. They need to work all the time, ignition on or not, and the high beam flash may also run from the same circuit.

Craftycarper3 said:

Thank you for your reply. I will check under the kick panel for any earth problems.
Strange about the immobiliser as it never used to do it, I could of left it hours unlocked & it would still start without having to demobilise it.
Only other electrical issue I have is the ignition is dodgy, it will only turn with the key facing a certain way. Strange lol

Click to expand...

The earth point behind each kick panel is easy to see, it's a central point for multiple black earth wires from various circuits meet.

The engine is remobilised with the fob being close to the ignition switch, if that hasn't done that before then who knows?, a fault somewhere or a modification to the system.

My key is very slightly bent as expected after 20 years of use so sometimes it won't turn in the ignition switch, but it does if I pull it out and turn it over, I should go and get a copy cut but it isn't a great issue, it it was then I've still got an unused original key and fob to in the draw that I could use.

The MFU has no bearing on the your hazard/horn issues, but there isn't any reason why you can't put it in its diagnostic test, which is a bit "spooky" but cool to see the stuff happening on there own

Circuit Operation, Multi-Function Unit
The multi-function unit (MFU) is mounted on the rear of the passenger compartment fuse box and has an input to operation of the following:
Heated rear screen
Heated front screen
Courtesy lights
Side and headlights
Rear fog guard lamps
Headlamp power wash
Front wipers
Rear wash/wipe

==================================================================
Testing.

Close all doors and the tailgate. NOTE: If the oil pressure switch goes open circuit (engine is started) during the following procedure, the MFU will exit the diagnostic mode immediately.

Press and hold the heated rear screen switch and switch on the ignition.
Release the heated rear screen switch within 2 seconds and the MFU will beep to indicate that it's in diagnostic mode 1.
Press the heated rear screen switch; the MFU will beep twice. In turn, operate each of the following switches, heated front screen, rear fog guard lamps, side lights, headlights, front wiper, and rear wiper. The MFU will beep twice each time a switch is operated.

Pressing the heated rear screen again will cause the MFU to enter diagnostic mode 2.
The MFU will provide outputs to the following in order given below:
Heated rear screen relay energized for 2 seconds
Heated front screen energized for 2 seconds
Courtesy lights energized for 2 seconds
Dim dip relay energized for 2 seconds
Rear fog guard lamp energized for 2 seconds
Headlamp power wash energized for half a second
Front wiper energized for half a second
Rear wipe/wash energized for half a second
The MFU will then exit the diagnostic mode