Honda CR-V - Disconnecting a faulty alternator

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Mon 4 Aug 2014 19:57
Honda CR-V - Disconnecting a faulty alternator - Pondlife

The alternator on my Honda CR-V has packed up. It looks like there's a short-circuit somewhere because it gets hot and smokes when the battery is connected.

I've got a replacement alternator, and now need to drive the car about two miles to the mechanic to get it fitted. I've got the battery charged, so will have no problem starting the car and driving it for a couple of miles without the alternator running, but I want to disconnect the alternator so it doesn't flatten the battery or (worst case) start a fire.

There are two electrical connections on the alternator: one wire to the main connection post, and four wires in a single connector to the regulator. I'm wondering which of these two connections I should disconnect.

Any ideas on what's the best thing to do? Just disconnect the main post terminal, just disconnect the regulator connection, or disconnect both?

I don't care about the old alternator, as it's dead anyway, but I need the car to run and don't want to flatten the battery if it's shorting.

Reply | Report as offensive | Link
Mon 4 Aug 2014 20:59
Honda CR-V - Disconnecting a faulty alternator - elekie&a/c doctor

Disconnect all the wiring,making sure that the main large power supply lead is well insulated,otherwise you will blow the main fuse if it shorts to earth.

Reply | Report as offensive | Link
Wed 6 Aug 2014 13:46
Honda CR-V - Disconnecting a faulty alternator - Pondlife

Thanks. That worked, and I've got the alternator changed now.

One thing that I found surprising is that there was no ignition light on when I was driving it with the alternator disconnected. I thought every car had this to tell you when the battery isn't charging, but apparently not the CR-V.

Reply | Report as offensive | Link
Wed 6 Aug 2014 14:17
Honda CR-V - Disconnecting a faulty alternator - jc2

If you disconnected ALL the wiring as instructed,there is no way it could work.

Reply | Report as offensive | Link
Wed 6 Aug 2014 19:04
Honda CR-V - Disconnecting a faulty alternator - Pondlife

If you disconnected ALL the wiring as instructed,there is no way it could work.

I disconnected everything connected to the alternator, which was the main post terminal and the connection to the regulator. And put some insulation tape round the post connector.

The battery was fully charged, so it started the car and worked fine for my short drive to the mechanic.

Reply | Report as offensive | Link
Wed 6 Aug 2014 15:00
Honda CR-V - Disconnecting a faulty alternator - MrEckerslikefromRamsbottom

A couple of weeks ago I found my 1.4 Tdci (186K miles) stuck on Tesco car park with a flat battery. No red light - no warning, but the alternator had failed. A jump-start from the Britannia Rescue man got me going again and I drove straight home and put the battery on charge before that went bad on me as well. Took me two days to decide which bits to disconnect (I had to take a power-steering pipe off and bend the dip-stick pipe out of the way, and a few other bits) in order to get the alternator out of the engine bay, then the helpful Simon at Motolec stripped it down and found that the brushes had worn through the commutator. £48 for a new rotor and brushes and it's working again, but there was no red light, no warning at all, and Oily Mick down Kay Brow tells me that he's come across that before.

Edited by MrEckerslikefromRamsbottom on 06/08/2014 at 15:03

Reply | Report as offensive | Link
Wed 6 Aug 2014 19:23
Honda CR-V - Disconnecting a faulty alternator - elekie&a/c doctor

Many late model cars have the charge/battery warning light circuit run through the engine control unit,so disconnecting all the wiring to the alternator puts the light on.This is most common on Ford models that use a smart charge system.

Reply | Report as offensive | Link

Choosing a child seat can be a quite baffling experience – there are so many sizes, types, brands and price points available that you might not know where to start.

How to choose the right child seat