Club 80-90 Forums

Latest update, got a jump start this morning from a friendly neighbour, and got home to a just kampers delivery of a new alternator. Fitted it this evening to a full battery (checked with a load tester as well as multimeter).

Full revs test and it generates 14.2 volts so a big improvement, and the battery light comes on when I half turn the key, which reading this forum told me that it is supposed to (it wasn't before).

Now the biggest challenge, convincing my wife that its safe to go away in again (assuming that the battery is full again tomorrow. I suspect the extra amps will also be enough to charge the leisure battery via the Sargent system which it wasn't before.

Re the battery, its less than a year old.

Ahh, if you drive a petrol engine and the alternator cant keep up then it will eat the battery. That could easily explain your 5v
The alternator and oil light should both come on when you turn the ignition ( to show they are working) and then not be on when driving.
Although if the alternator isn't charging then the light should be on ?

hotpod wrote: ↑26 Aug 2026, 22:50 Ahh, if you drive a petrol engine and the alternator cant keep up then it will eat the battery. That could easily explain your 5v
The alternator and oil light should both come on when you turn the ignition ( to show they are working) and then not be on when driving.
Although if the alternator isn't charging then the light should be on ?

not sure what you mean, there is no reason the charging system can't keep up petrol or derv.


how is current draw being measured as it seem unclear with mention of meter on -ve and +ve , the draw needs to be measurded inline from the +ve to the feeds.

there should be no need to add a switch for the head unit, just add the correct acc/ign feed into the unit, if its powered all the time you have a faulty unit.

Possibly the last update in this story.

This morning the battery is still fully charged, the radio is still out so the draw from that needs to be tested, i know it did draw a little so a future fix is to install that switch, but for now, the van is good to go.

A question asked was whether I should replace the battery. It never sat on very low charge for more than a day or two so I am hoping that it doesn't suffer too much long term damage.

Thank you for your input and guidance, it was invaluable.

One thing i did this time that i haven't before was point Microsoft Copilot at the site and ask it to provide instructions on how to remove and replace the alternator for specifically my engine, and that, alongside the paper manual I have in the van, and it worked perfectly.

I am not saying that Copilot fixed it for me, it's the collective wisdom on just this site that did it, all the AI did was distil your brilliant minds.

Now I only need the weather to get better!

I had a battery drain years ago since installing a sony stereo cd player. VBaytery would be dead after a week.

I would remove the fuse.

Replaced the stereo now with a Chinese android amd wired the radio to ignition on with updated ognition switch.

TwinTurbo wrote: ↑26 Aug 2026, 23:13

hotpod wrote: ↑26 Aug 2026, 22:50 Ahh, if you drive a petrol engine and the alternator cant keep up then it will eat the battery. That could easily explain your 5v
The alternator and oil light should both come on when you turn the ignition ( to show they are working) and then not be on when driving.
Although if the alternator isn't charging then the light should be on ?

not sure what you mean, there is no reason the charging system can't keep up petrol or derv.

If the alternator isn't charging properly then the ignition system on a petrol will eat the battery for breakfast. The alternator is running the engine and vehicle electrics and at the same time charging the battery ready for it's next bout of cranking. If you are running at night in the rain and cold too, then it will be even quicker with lights, fan and wipers on.
On a van with a properly functioning charge system, the starter battery isnt usually a problem.
 

Hmmm...

5 volts to me means battery dying.

When fully charged, a lead acid battery should be at about 12.6 volts.
By the time it gets to 11 volts it is discharged.
I appreciate that you can get a reasonable reading... say 12.2 volts after charging, but the battery will fade very quickly

Cordialement,

Alternative to pulling the stereo out is remove the 15A 3rd fuse along on the top row in the glove box.