Member Since: 05 Jan 2024
Location: South Wales
Posts: 75
Alternator and battery light
I've looked through the forum, but couldn't find an answer to what I need.
Would any of the gurus know whether the ALT-Mon or ALT-Con signal on the alternator is responsible for bringing the battery warning light on, on the dash? I guess it's not as simple as that, but I'm thinking one or all the cables could be at fault.
The light was permanently on when I bought the car, and the previous owner (a Land Rover mechanic) said it needed a new alternator so I've fitted a new battery, and recon alternator (DENSO) but it's still the same. I get a permanent 14V when it's running. I want to check continuity from the alternator to the ECM, but don't know which plug on the ECM has the wires mentioned above, if anyone can help?
I would guess that someone else has had a similar issue over the years that might be able to shed some light on the issue?
CheersVolunteer driver with 4x4 Response South East Wales
Volunteer Rider for Blood Bikes Wales
Land Rovers owned -
Disco 1 - 300 Tdi - dead
Disco 1 - 200 series - 3.5 V8 on LPG - dead
Disco 2 - TD5 - sold
Disco 1 - 300 series - 3.9 V8 on LPG - sold
Disco 3 - TDV6 HSE - current
I have had this problem with a broken wire, its only a thin wire so easy to break. Give Pete K a message he will tell you what plug to check the wire continuity .
Flack
7th May 2024 8:56 am
skunk38
Member Since: 05 Jan 2024
Location: South Wales
Posts: 75
Cheers Flack, I'll drop him a message.
I can see on the wiring diagram it's plugs C0411C-H1 & C2518C-F2,but can't find any info which ones they are.Volunteer driver with 4x4 Response South East Wales
Volunteer Rider for Blood Bikes Wales
Land Rovers owned -
Disco 1 - 300 Tdi - dead
Disco 1 - 200 series - 3.5 V8 on LPG - dead
Disco 2 - TD5 - sold
Disco 1 - 300 series - 3.9 V8 on LPG - sold
Disco 3 - TDV6 HSE - current
7th May 2024 10:18 am
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7th May 2024 10:47 am
skunk38
Member Since: 05 Jan 2024
Location: South Wales
Posts: 75
Thanks Martin. That's brilliant.Volunteer driver with 4x4 Response South East Wales
Volunteer Rider for Blood Bikes Wales
Land Rovers owned -
Disco 1 - 300 Tdi - dead
Disco 1 - 200 series - 3.5 V8 on LPG - dead
Disco 2 - TD5 - sold
Disco 1 - 300 series - 3.9 V8 on LPG - sold
Disco 3 - TDV6 HSE - current
7th May 2024 11:12 am
skunk38
Member Since: 05 Jan 2024
Location: South Wales
Posts: 75
Well I found the problem and the battery light is now off.
The red sense wire from the alternator to the fuse box is at fault, but I don't know where it's broken.
I've replaced the original alternator plug as that was damaged/brittle, and checked continuity of all 3 cables, of which the other 2 wires were ok. The red wire looked like it was broken internally just after the plug, but cut it back and retested it with no change, so suspect the break is further along the loom.
I've made a semi permanent fix by running a new wire from the plug up to the fuse box, and using a piggy back fuse holder into F20 until I have time to remove the fuse box to splice into the cable for a permanent fix.
Hopefully it will stay ok now until I can do the permanent fix.
Onto the next job...hey ho.Volunteer driver with 4x4 Response South East Wales
Volunteer Rider for Blood Bikes Wales
Land Rovers owned -
Disco 1 - 300 Tdi - dead
Disco 1 - 200 series - 3.5 V8 on LPG - dead
Disco 2 - TD5 - sold
Disco 1 - 300 series - 3.9 V8 on LPG - sold
Disco 3 - TDV6 HSE - current
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