Freelander 1 Push started my 2001 1.8 FL1 and the alternator's blown?

Lockdown has been a pain for many reasons, but perhaps one of the more trivial reasons being lack of use of my dear old FL1. It's been used intermittently, but recently the battery was too low to start the car. I jump started it from a good battery, but unfortunately it didn't have quite enough charge to re-start again having popped into a shop.

No problem, thought I, I'll push start it! The car park was on a hill - but after a couple of attempts the engine fired up.

Then the bad stuff: the battery light remained on. Ooops. A hot electrical smell under the bonnet. Oh dear... Got home before the battery finally ran out of juice and popped a volt meter over the battery: 8V at idle (SRS and three-amigos lit) and 10V at 2,000rpm. Bu99er.

I reckon I've toasted the alternator.

Thing is, I've done this many times (many years of crap car ownership) and have never encountered this problem before. Has the rectifier been fried? What did I do wrong? (Other than the obvious of letting the battery go flat and not charging it enough before going to the shops!)

Answers on a postcard to the usual address please

That's bad luck. Didn't know bump starting could do that. Wonder if its just coincidence and it was on its way out anyway. Maybe it was the driving on a battery low on power and the alternator was trying to gen to much current?

Yes, maybe the high charge load finished it off?

it’s a Denso alternator. I’m not sure of the diagnostic checks on these but currently on lock out for a suitable replacement - hey ho!

I'd say it was getting duff and probs the reason the battery didn't hold up in first place.
Damage to alternators is usually worn out brushes or failed diodes. Running them into an open circuit can cause damage so maybe it couldn't see the battery for some reason, either through being very flat or you've got a high resistance in the circuit somewhere.

To be honest I wasn’t surprised the battery was flat: I’ve been working from home and not travelling around much! But you never know. I don’t have a voltmeter in the car, so perhaps the thing was on its way out and I wasn’t aware?

Check the alternator cable isn't melted where it goes past the exhaust. I've seen the outer casing melt and weld the copper inside to the manifold on more than one occasion.

Thanks! Will do

Replacement alternator has arrived from the bay of fleas. Unfortunately working this weekend so no time to fit - but hopefully should not take too long. I suspect I'll need access from above and below - so probably a good opportunity to perform a full oil service.

Doing the alternator on a 1.8 FL1 can be a PITA. It took me about 2 hours when I did it on the Tonga 1.8. I can't remember what the issue was now, but I'm sure it wasn't as straightforward as I hoped. I think the AC compressor needed moving aside, which might not be an issue with yours.

Hopefully not - mine doesn't have AC - one of the advantages of getting the bog-standard version?

A little update. After the alternator fail, I took the battery out and went in a spend on the bay of fleas. I scored a second hand alternator for under 20 quid and decided to buy a lithium jump pack (Top Don for 55 quid).
The jump pack works a treat and a doddle to use - easily started a neighbours Honda.

I was going to replace the alternator this weekend but for one reason or another (DIY in the garden mostly) I did not get around to this.
This evening however I put the now charged battery in the Hippo.

naturally, the hippo just started at the first attempt, but to my surprise, the alternator charge light did not illuminate.

I’ll check the voltages when I get a chance, but the Landy seemed absolutely fine (bar for the unwelcome appearance of the two amigos - I guess that’s the brake light switch?)

Perhaps the badly discharged battery was just too much for the alternator? I have a hunch I’ll be replacing it soon - that surely can’t be normal behaviour?!?

The alternator should be protected against over current and not smell of burning as a warning !!!
Maybe it was the battery smelling hot?
Maybe the alternator regulation is up the duff and, under normal circumstances it doesn't matter but when the load is increased then it does ?

Just thinking out loud - or on paper so to speak.

That's what I am thinking too Andy - I may just wait and see, but it may be the alternator is on borrowed time?

If it is smelling hot and not limiting current output then it is a fire hazard to itself and cabling.

It is not malodourous at the moment Andy - but will check this carefully.

8v is a very dead battery. A battery in a very bad state can do bad things to an alternator!
Also remember alternators aren't designed to charge totally flat batteries, but to top up after engine starts and provide current to the rest of the system

As a penniless student, I mastered the art of the single-handed jump start (just need a downward slope, a shove and the ability to rapidly sprint and jump into the driver's seat). Never fried an alternator before though? Strange. But excess charge load may have been pat of the problem here...