Classic Range Rover electrics

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Discussion

akirk

Original Poster:

5,623 posts

121 months

Tuesday 5th September 2023
quotequote all
I have a 94 soft dash range rover
There is a weird electrical issue - when you start the car it is a lottery as to whether half the electrics work or not (windows / wipers / air-con / etc.) - sometimes they do, sometimes they don't. Usually if you turn the car off and then back on they will then all start to work - though this morning it took 5 attempts before they worked...

I assume that it is a loose wire / earth wire somewhere - is there:
- any cleverer answer (I have very little knowledge of cars)
- anything I can do to try and track it down / fix it
- in reality an auto-electrician is needed...

any thoughts welcomed!

OutInTheShed

9,380 posts

33 months

Tuesday 5th September 2023
quotequote all
I think I would be asking on a model-specific forum but:

What's common to all the things that don't work? Some sort of 'body computer'? Secondary fusebox? Branch of wiring loom?

'94 is modern enough that some cars had a fair bit of electronics in them.
As a starting point, check the battery volts, and what they dip to during starting.
Some vehicles which do odd things but behave on a re-start, it's because the 'electronics' need a reset after seeing low voltage.
Some vehicles of this era also had significant drain from the battery when not in use. A trickle charger makes them less moody.

LandieMark

1,827 posts

155 months

Tuesday 5th September 2023
quotequote all
I would imagine that this is the same as a late Discovery 1. The BCM controls all the locking, windows, interior lights and wipers. In the D1, it is behind the glovebox and causes all sorts of strange symptoms due to dry soldered joints.

I changed it for a known good one via a breaker on eBay and it solved my dodgy wipers, lack of interior lights and non functioning windows.

akirk

Original Poster:

5,623 posts

121 months

Tuesday 5th September 2023
quotequote all
Thank you - both helpful thoughts
The car sits permanently on a trickle charger, so battery is in good condition (also very new and good quality)

BCM - will need to investigate, not sure if they do - the P38 had something similar which caused a lot of issues but I am not aware of one for the classics - will investigate!

paintman

7,765 posts

197 months

Wednesday 6th September 2023
quotequote all
Late Classic & Disco 1 have a Multifunction Control Unit.
Part AMR1280.
https://new.lrcat.com/#!/1229/80905/82320/6494/823... Item 4.
Under the fuse box.

Eyewatering new.
Plenty of used on ebay.

The P38 has a BECM. Different animal.

akirk

Original Poster:

5,623 posts

121 months

Wednesday 6th September 2023
quotequote all
paintman said:
Late Classic & Disco 1 have a Multifunction Control Unit.
Part AMR1280.
https://new.lrcat.com/#!/1229/80905/82320/6494/823... Item 4.
Under the fuse box.

Eyewatering new.
Plenty of used on ebay.

The P38 has a BECM. Different animal.
Ahhh - interesting, thank you - worth investigating... the car is so good that the occasional electrical bits are frustrating...

LandieMark

1,827 posts

155 months

Wednesday 6th September 2023
quotequote all
paintman said:
Late Classic & Disco 1 have a Multifunction Control Unit.
Part AMR1280.
https://new.lrcat.com/#!/1229/80905/82320/6494/823... Item 4.
Under the fuse box.

Eyewatering new.
Plenty of used on ebay.

The P38 has a BECM. Different animal.
Knew it was something like that but couldn't remember the proper term. I just remember swapping it out for a used one sorted all of the above electrical problems.

OP, I suspect your wipers will work on single speed only when it goes wrong, just not intermittent and they wont come on with washers as they should.

DKL

4,624 posts

229 months

Thursday 7th September 2023
quotequote all
Not on my RRC but 944, the ignition barrel would sometimes stop a large chunk of the electrics working, including the cooling fans (!). The car would start and run normally but needed a wiggle to get the rest to kick in.
Seemed an easy fix but it's been a while.

akirk

Original Poster:

5,623 posts

121 months

Thursday 7th September 2023
quotequote all
well car has refused to start today - despite the ctek charge being plugged in and saying the battery is in tip top condition - so I suspect there may be a bit more to investigate... AA on their way for the first stage diagnostic!

akirk

Original Poster:

5,623 posts

121 months

Friday 8th September 2023
quotequote all
so - intriguingly, the battery was low - hence not starting...
alternator seems to be delivering correct power
battery tests as a good battery (and is only c. 1yr old)
but the level in the battery was low - despite being plugged into a ctek charge which was reporting that all was well with the world - not sure that makes sense to me!