NA electrical mystery

So, I bought a mk1 NA at the weekend and had a couple of electrical issues. It cranked fine then suddenly stopped turning over. Thus far I’ve replaced the - battery, main fuse, spark plugs. I get dash lights and headlights (I’ve removed the radio for the time being). I do get a battery warning (battery is new and fully charged) and it seems to drain as soon as I attach it. Any help massively appreciated








Possibly the starter itself? You mention it has a couple of electrical issues  so assume not cranking is one. What are the other electrical issues as these may well be connected?

Could also be a fault with the ignition.

The other was the radio itself (not fantastically fitted and wasn’t grounded) .

Turn the ignition and it sounds like its going to crank but somehow can’t make it over the line — turn the key and it just kind of stutters. I’m thinking alternator at the moment. I’d searched the forum and found similar (but not quite) descriptions hence me doing the “rule it out list”. The fuel gauge is just shy of empty could it be misreading it and is actually empty?

Thanks for quick reaponse




Nothing to do with the alternator - that keeps the battery charged once the engine is running.  You say the battery is fully charged.

I would be investigating basic electric feed leads (positive and negative) in the boot.  Check all earths. Then move to starter motor itself, and supply to it.

Check all the ground connections. The one on the PPF frame near the rear axel and the main engine ground points.

Thanks very much - job list for tomorrow. Don’t suppose there’s any photos of what I’m looking for?

Get some petrol, and try again. If you have a multi-meter, Disconnect the battery negative lead and check on the resistance scale that there’s no direct reading (zero ohms) between Positive lead and chassis. What battery are you using? If it goes flat immediately you have a major problem. You need an Auto-electrician to check the electrics out - unless you are good at electrics yourself? (Not many are, so don’t feel bad about it.)

Check that the main earth lead from the battery negative terminal to where it joins the body hasn’t got a load of broken strands of wire in it, this can cause a massive voltage drop when cranking.

Couldn’t see any fraying. Replaced all fuses I can access. Battery is a vpower 063vp, I’ve also got a yuasa 1000.petrol topped up. Still no joy getting it started :/. Starter motor may be fried going off what others have said





How many volts across the battery terminals at rest ? It’ll tell you the state of the charge. If it’s 12+ volts, you’re issue is likely to be an earth problem. If it’s less than 12v you’ve got a discharge issue or sulphate battery. Discount the latter as you’ve replaced the battery recently.

How are you getting on with it??


A faulty rectifier on the alternator can cause battery drain, quite a quick one too, and a loss of output which will bring your charge light on sometimes…




Been waiting for a new starter motor to arrive so have had an impromptu break from it. Am now just waiting for some axle stands so I can properly investigate - either rectified or more questions this weekend :) 

So, this is embarrassing. Got my brother-in-law over (mechanic) as I was drawing an utter blank and talked him through it running and then not. There’s a switch in the arm rest box…it isn’t for the aerial as thought…its a bloody immobiliser! :smiley:

“click” - starts first time! 

Would have been so easy for you too say you had found a faulty earth lead but you came clean. Fair play to you sir.

You do realise you are not going to live this down for a long long time.

And we all know where your immobiliser switch is 

I suppose it was a good excuse to get a load of new bits for it :) 

The radio still resets itself with the engine off, though :confused: