Jump to content

Alternator and battery failure together?


honda

Recommended Posts

  • Platinum Member

2012 Grand Cherokee Overlander 35,000 miles

 

Jeep just stopped no warning lights, tried to jump start no success and towed to dealer.

 

Advised new alternator and new battery required. Is this unusual? Have had the odd battery die on other vehicles but always with warning signs. Once had alternator failure but plenty of warning as no charge warning light came on well before battery exhausted so limped home.

 

Quoted circa £1500 for replacement of both. 

Link to comment
Share on other sites

  • Platinum Member

Yes. It happened to me too on my 1993 XJ a few years ago. The battery was replaced six months before I diagnosed the alternator fault and I had to replace both. I had no warning signs of battery failure on both Calcium batteries. I did the repair myself. I am fairly certain my failing alternator caused the previous battery to fail. If I hadn't been so lazy not checking the alternator six months sooner I could have saved the cost of one battery. I bench charged the failed batteries each time, then tested them under load with a 4hp electric motor to check performance.

 

A bad battery can kill an alternator and a bad alternator can damage a calcium battery so mine was a chicken and egg type of problem.

Also a loose battery cable or faulty mechanical battery cutout can kill an alternator when the engine is running.

There is usually a battery temperature sensor built into the floor of the Jeep battery tray that can cause problems if it gets disconnected.

On a modern computer controlled alternator, a broken or corroded control circuit can stop the alternator charging properly which then kills the battery.

 

My repair was a lot cheaper:

New battery £80

New alternator £110

New Gates serpentine belt £20

Link to comment
Share on other sites

  • Area Representative

Seems nowadays once an alternator starts to go it often takes the battery with it unless you catch it straight away.  Had to replace my alternator and then battery couple of weeks later on my Discovery

Link to comment
Share on other sites

  • Platinum Member

Hi, I had similar on my Saab 93, 4 year old Saab, electronics failed on alternator did not charge the battery - no warning, then all electronic systems failed 1 after another while driving, in a matter of minutes.
luckily the lead acid battery was ok, just flat. Otherwise a new battery as well, so yes both can fail at the same time. £1000 new alternator, as it could not be repaired. 

Link to comment
Share on other sites

  • Platinum Member

Thanks all, I feel a bit better now but after many years of motoring in various vehicles never had a total stop without warning and even when a battery went flat it was possible to get a jump start. Just as well it didn't happen on a motorway with a fully laden horsebox!

 

Reply from 998 mentioned "calcium" battery, I am not familiar with this, is it another term for lead acid which is what I assume is on my Jeep?

If different are there any specific do's and dont's as when away I have occasionally left the car on a trickle charger?

Link to comment
Share on other sites

  • Platinum Member

A calcium battery is still lead acid, but uses calcium instead of antimony between the plates. That’s my understanding.

my Saab battery lasted 9 years, a good age for a battery. If the battery is old and alternator issues, it will probably kill the battery as well. I would expect a battery to last 5-10 years. Trickle charge does not damage it. 

Link to comment
Share on other sites

  • Platinum Member

Caroline 12

Thanks, I am not technical and on a "need to know" basis! Thanks you have put my mind at rest that I am not doing anything wrong!

  • Like 1
Link to comment
Share on other sites

  • 2 weeks later...

On the Australian WK2 Facebook page, there seems to be a litany of complaints with this happening. FCA in Australia seem to regard it as a known fault and will sometimes pay for replacement. Symptoms as you describe; just stops, and won't go until it's fixed with new alternator and battery. Make sure it's an AGM battery, since it's inside the passenger compartment.

I had a lot of problems with strange error messages after flattening the battery during the first lockdown, but a new battery solved all those problems and there have been no alternator troubles, before or since. 

Link to comment
Share on other sites

  • Platinum Member

Thanks, useful information. 

 

Who is FCA in Australia, are they a Jeep dealer? If there is anything on the internet about it being a "known issue" I might be able to take it up with the local dealer.

 

Thanks. 

Link to comment
Share on other sites

  • Platinum Member

Perhaps the diodes in the alternator are upgradeable?

An alternator diode pack is a Bridge Rectifier. It turns Alternating Current (AC) into Direct Current (DC).

I have replaced these before on Lucas alternators, maybe they can be replaced or upgraded on a Jeep alternator.

It is worth asking an Auto Electrician that does alternator repairs.

Link to comment
Share on other sites

  • Platinum Member
46 minutes ago, V said:

Perhaps the diodes in the alternator are upgradeable?

An alternator diode pack is a Bridge Rectifier. It turns Alternating Current (AC) into Direct Current (DC).

I have replaced these before on Lucas alternators, maybe they can be replaced or upgraded on a Jeep alternator.

It is worth asking an Auto Electrician that does alternator repairs.

 

It can be done. I replaced the rectifier, regulator and brushes on my CJ alternator. Not actually a difficult job to do, depends where the alternator is though and how easy it is to get to.

Link to comment
Share on other sites

  • Platinum Member

Thanks that is really helpful.

 

I will refer this to the local dealer and perhaps to Jeep in the UK with a view to claiming that the diodes are not fit for purpose and possibly I am due some sort of compensation.

Link to comment
Share on other sites

  • Platinum Member
mad mechanic

you will be lucky to get anything from jeep, after all its 9 years old lol.. the batteries just die on these and this in turn takes out the alternator. Done a few over the years and genuine batteries are lucky to last 3 years tbh.

Link to comment
Share on other sites

  • Platinum Member
Wildjeeper62

I bought a WK2 V6 which was on 62 plate with 74 000 miles on the clock and a fortnight later the same thing happened to me on my way home from work. Like Stewart said there is recall but not applicable to the Diesel unfortunately, only to the 3.6 and 5.7 Petrol engine despite that they are all fitted with the same alternator. So if yours is a Petrol Engine you can call Jeep and have it done for free but if it's the 3.0 Litre V6 Diesel engine unfortunately you will have to fork out the money.

I bought one from Germany to get a decent one (SKF) at affordable price (£250) as a Lucas from over here is around £400. I replaced it myself on my drive, no workshop, but if you are not used to work on your Jeep I would suggest that you leave it to a professional as there is a bit involved and you need to drain the radiator to remove all hoses in order to access.

 

I think £1500 for that job is a bit High though, specially because it is very likely that like me once the battery has been recharged and the alternator replaced it worked fine. A pro would do that job in a couple of hours so if I was you I would get a quote from somewhere else.

 

 

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

guidelines