Electric issues

Last night coming home, the car lost most all electric power. It slowly died and the lights dimmed until it came to a complete stop. Probably over a mile or two.

Whilst I was calling the breakdown people, we tried it again and it was fine, started right up. A few miles down the road it did the same thing.

We got into a pub car park; lights were very dim, wouldn't turn over and the wipers were on massive go slow; so seemed like a flat battery.

Sat in a pub for an hour waiting for the tow truck, and on coming out, it started straight up, full power. We ran it for 15 minutes, and all seemed fine. The tow truck followed us home for 10 miles and no issues.

I've check the connections etc, and it all seems fine and starts no issues.

Anybody got some bright ideas? Clearly there is a problem somewhere but I cant spot anything, and I don't really want to just start replacing stuff, with most likely culprits being battery and alternator I guess.

Cheers

 

Which ones? If the wipers were slow, I'm guessing it was raining. Did you look at the circular connector near the left hand rear shock absorber?

 

I would check in the following order:

1. Alternator belt tension
2. Battery cable quick connectors (under the air filter box) - disconnect and clean if corroded/burnt
3. Battery terminals - remove and clean if corroded, tighten properly
4. Connection of the battery negative cable to the body - undo, clean and tighten back
5. Check the voltage on the battery while the engine is idling, lights on, AC on, wait until the cooling fans come on - you should have 13 to 13.5 volts

 

If the battery is older than 5 years, replace it. If the alternator has never been rebuilt, rebuild it. In the process, you will have checked and tightened all relevant connections.

Good luck.

 

check those bullet connectors under airbox too!

 

Thanks all.

A few points there I haven’t checked; most notably the connectors under the air box, didn't know about those so good to know.

I’ll go through the above list later this week when I get backend let you know what I find.

Appreciated

 

Sounds more like an intermittent alternator issue, or connection to the alternator. Something gets hot and the voltage from the alt drops.

 

Went through the list and all good. Only two things I found was a positive wire behind the foot well fuse panel cut but not taped up; I think this was me when I took the immobiliser out. And some oil on the alternator; I’ve got weeping cam seals.

Run it a few times now and no problems.

All I can think of is that when I parked up at a friends house it was on a slope, nose up and that a little oil might have dripped onto the alternator and upset it! We will see, a few long runs coming up over the next few weeks so fingers crossed!

Thanks for all the suggestions.

 

OMG I was going to suggest check the alternator for oil since my seal leaks too and my alternator was oil covered. I figured that would be a long shot and not add any value. ha! I made a shield for oil and heat to prevent it from going bad till the seal is fixed. The oil dripping from the seal will coat the alternator.

For reference you may want to consider a drip/heat shield combo. There are oem shields too but its easier to make a better one. I sprayed contact cleaner all up in there too to clean it out.
https://www.ferrarichat.com/forum/threads/alternator-shield-diy.604393/