Disco 1 Wiring problem

Posted yesterday in the Members Vehicle thread but no replies

so here goes

300TDi Discovery (Project)
Currently helping to get a poorly 50th Anniversary Discovery back on the road.
All welding now complete and only a few niggly bits and bobs still to go before MOT.
Found an aftermarket Off/On switch on the dash beside the front fog light switch with 2 wires (blue and brown) heading up behind the steering wheel and into the rear of the instrument cluster.
I removed the cluster to find this mess



For some unknown reason all the wires going to the right-hand multi plug had been cut and joined with connector blocks.
One wire No.2 Black/Red was cut and each end then connected to the blue/brown wire from the switch.
I spent an hour with the soldering iron and shrink tubing sorting this mess but before removing the switch and extra wiring, wonder if anyone can shed any light on why the switch was used in the first place.
Had a look a RAVE but the Wiring Diagrams for the 300 aren't very amateur friendly.
Here's another look at the mess

Ok had a look for you. Wire Green/yellow comes from fuse 14 to pin 1 of connector C370 feed for vehicle speed sensor. Black/red wire goes from pin 3 of C370 back to pin 2 of connector C221. The one you are looking at. So it looks like the switch disabled the speedo for some reason.

Cheers for that, wonder why whoever did all that damage needed to turn the speedo off.
Would that have turned of the mileage moving forward as well or just the speed?

biggeeeee said:

Cheers for that, wonder why whoever did all that damage needed to turn the speedo off.
Would that have turned of the mileage moving forward as well or just the speed?

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If the odometer is driven electronically yes. Sure my 1994 Disco 1 had a cable, yours doesn't appear to have one. So the later ones appear to be driven (speedo and odometer) by pulses from the speed sensor.

Yeah, no speedo cable.
Follow the track on the rear of the instrument cluster from the black/red wire and it terminated at SP IN.
Oh well I'll reconnect the wire and do away with the switch and monitor the bloody think.
Cheers for the info, appreciated

biggeeeee said:

Yeah, no speedo cable.
Follow the track on the rear of the instrument cluster from the black/red wire and it terminated at SP IN.
Oh well I'll reconnect the wire and do away with the switch and monitor the bloody think.
Cheers for the info, appreciated

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No problem happy to help.

Wonder if it was owned by someone I used to know? They habitually disabled their speedo/odometer on their lease cars so they wouldnt exceed the mileage allowance!
Probably more difficult on new cars with data logging, but does justify my view on "low" mileage being less important than condition!
Mark

markomate2 said:

Wonder if it was owned by someone I used to know? They habitually disabled their speedo/odometer on their lease cars so they wouldnt exceed the mileage allowance!
Probably more difficult on new cars with data logging, but does justify my view on "low" mileage being less important than condition!
Mark

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The speedo reads 168000 miles, wonder what the mileage really is?
Still wonder why they cut all the wiring to the plug and not just the correct one

You can do a part check on the mileage with the DVLA MOT history check. But if its been bought in from abroad it wont have a history.
Ive seen the strangest things on wiring, not just on cars, you should see what folks do to boat wiring!
Mark

markomate2 said:

You can do a part check on the mileage with the DVLA MOT history check. But if its been bought in from abroad it wont have a history.
Ive seen the strangest things on wiring, not just on cars, you should see what folks do to boat wiring!
Mark

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That's the strange thing the MOT history charts the whole thing. Most years Discovery did between 10 and 12 thousand miles, there doesn't seem to be any discrepancies.
Think its also had 7 previous owners.

Just checked again, must have been my TD5 that has all the mileage history on the MOT check site.

The Project Disco with the shitey wiring is only listed from 157000 in 2012. So no history prior to this covering 14 years

biggeeeee said:

Just checked again, must have been my TD5 that has all the mileage history on the MOT check site.

The Project Disco with the shitey wiring is only listed from 157000 in 2012. So no history prior to this covering 14 years

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If it's been on the road 11,000 is not a lot. 3,600 a year. ASDA trolleys do more than that.