Skip to content

Electrical gremlins

Featured Replies

It all began with starter not working which I had replaced then al of a sudden alternator dies. Which was replaced but two new alternator wouldn't charge my battery so thought maybe alternator wiring loom was problem new one bought and fitted. But still no charge going to battery. I am at a loss what could be wrong. Fuse box on battery is fine help anyone please

There is connector attached to a bracket on the starter motor. There are two signal wires that run down the thick cable to the alternator. The two wires are blue and brown/red. One of these is broken or the connector is not plugged in correctly. It probably happened when the starter was changed.

On a car with a/c there are four wires, but you can ignore the other two as they run to the a/c compressor.

  • Author

Thank rwbaldwin I will check them tomorrow as an about to go to work. The plug was part of alternator loom so that side should be good as been replaced as said earlier but I havnt checked starter side. Hopefully ur knowledge is better than mine

  • Author

Rwbaldwin you were spot on thanks for the help. Have had to order new plug as no where near me has one in stock. Then will have to solder in new wiring. Hopefully car will be back to old self after this

  • 4 weeks later...
  • Author

No luck. Still not charging had to strip brown wire quite a lot as was full of rust. All wire soldered and heat wrapped and tested for continuity with no issues. But still not charging, anyone ideas anyone

Have you tried putting a multimeter over the alternator whilst the car is running to see if there's a charge being generated ? Be very carefull to not get trapped in the belts/ pulleys if you do

Hope this helps

If the continuity between the connector and the alternator is now good, you need to check the other way.

The blue wire goes direct to the dash insert (pin 12, blue connector) without intermediate connectors.

The brown/red wire goes to the ECU (pin 22, large connector). There is an intermediate connector in the connection box (pin 5, 10-pin green connector). The connection box is in the plenum chamber, under the wiper motor. If the drains in the plenum chamber become blocked, the connectors in the box can 'wick' water and become corroded.

Good luck

  • Author

The alternator is generating charge but for some reason th charge is not getting to battery. Thanks again rwbaldwin will check that out. The brown/red wire at starter I had to cut back good 8 inches to find good wire

Do you have any 4 gauge flexible wire ? If so you could put a ring terminal on either end and just replace the standard one ...

  • Author

I will pick up some wire and try bypass old wire see if corrects problem if it works I will replace it

Nobody's mentioned the engine earth lead yet...

How's your starting?

  • Author

Car starts first time when battery has some charge in it. Battery is fine have had it tested and it holds charge when as have put it on a charger. What earth lead would u be thinking of might need attention.

Engine earth strap.

Car starts first time when battery has some charge in it. Battery is fine have had it tested and it holds charge when as have put it on a charger. What earth lead would u be thinking of might need attention.

The engine earth strap provides the earth to both the starter motor and alternator (amongst other things). That's why you only see one large cable to the starter and alternator. As the car is starting well, it is unlikely to be the earth strap.

Has been known. My Volvo used to start fine, although it would crank a fraction on the slow side (and the op hasn't really described the starting other than it starts first time), but it wouldn't charge until I replaced the earth strap though. Just a thought, and should be checked regardless. In fact, it would normally be the first thing I'd check other than the obvious terminals.

I'd check that with a megger, then I'd check the negative battery terminal direct to the alternator body with a megger, just to narrow things down and rule out earth fault.

  • Author

The alternator loom has been changed which I assume is the earth strap being suggested. The starter turns over well and starts car first time. There isn't any hesitation or slow turning over

No. The earth strap is purely between the engine and the chassis. The alternator gets it's earth from the engine. Which is why you should also check for a good clean connection between alternator and engine.

  • Author

Ok will give that a check any idea where earth strap may be

  • Author

Only earth have been able to find is battery negative and there no issues with that. Unless I'm missing something someone knows about. Havnt had the chance to try bypassing brown/red wire as pouring rain tried flooding me out so that's for another day

Create an account or sign in to comment

Recently Browsing 0

  • No registered users viewing this page.

Important Information

Welcome to BRISKODA. Please note the following important links Terms of Use. We have a comprehensive Privacy Policy. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.

Account

Navigation

Configure browser push notifications

Chrome (Android)
  1. Tap the lock icon next to the address bar.
  2. Tap Permissions → Notifications.
  3. Adjust your preference.
Chrome (Desktop)
  1. Click the padlock icon in the address bar.
  2. Select Site settings.
  3. Find Notifications and adjust your preference.