Make sure the spade connection on the trigger wire to the starter motor is sound and fits snug. check the connection between the wire and spade connector for fraying. Remove and clean the earth cable from the battery to the earth to somewhere between the gearbox and engine. Replace relay 103. This is the glow plug relay and should not click so you hear it. Check the glow plug fuses by the battery. These are flat fuses. Relay 109 is another one to watch for. Try to borrow one for testing. Takes a couple of minutes. The click from the engine bay is the starter motor clicking.
Try to short the starter motor between the spade and + to see if that turns the engine round. If not, your starter motor is faulty.
This sounds like a simple fault and wont cost you too much money. You have already spent some money on a trial and error basis.
I am sure there are guys here who can help you out.
Did you buy a quality ignition switch? If not, short the 2 largest pins with the key in the ignition and see if it starts.
Keep the engine bay clean and dry.

 

Thanks for the reply. I have already done the things you have suggested, but I will run through them again tomorrow just to be sure I haven’t missed anything. It’s easy to get frustrated with this sort of problem and forget something reasonably simple!! The switch came from Euro Car Parts. As I said when I have used a jump pack connected it starts fine so I’m reasonably confident the switch and starter are ok but again I’ll check it tomorrow and let you know what I find. I will also but a new relay just to eliminate that from the potential causes. Thank you for the suggestions.

 

I thought I’d chip in here as it’s my old van ! And it was always very reliable.

As I said when I have used a jump pack connected it starts fine...

This says “dodgy battery” to me. If it starts OK with a jump pack then glow plugs, starter motor, ignition switch etc must all be working.

After that I’d start looking at the glow plugs maybe.

 

Actually, having pondered some more, I’m wondering if the glow plug relay / timer has got stuck “on” and is killing the battery. Pull the relay and see if the voltage still plummets when you turn the ignition on.

 

Charge your battery and leave the lead off it until your ready to start it,if it starts something is draining it,if it doesn't your battery is duff or better still get the battery checked properly

 

Have you gt a multimeter?

Try a current draw test. Positive lead off of battery and multimeter set to amps then bridge the connection. Video here explaining how
https://www.youtube.com/watch?v=yFCT-YZbU5o

If you find there is a parasitic drain then remove, fuses/relays one at a time to isolate

Don't rule out a faulty battery just because it is new, same applies for the starter however, my gut feeling is that something will show up when you test.

 

When you fitted the new battery, did you clean the terminals 1st?
They often come with a layer of "wax" on them to stop them corroding.

As Sundayjumper says....even a new battery can be faulty!

 

Thanks for all the advice. I have run out of time and light today to do anything but I will try your suggestions tomorrow and hopefully have some results. I have bought a new relay to rule that out, I did clean the battery terminals as suggested and I’m going to take the battery back to the shop and ask them to check it is working properly. Hopefully I’ll get to the bottom of this tomorrow. Thanks guys.

 

So... before the weekend I fitted a new battery, the original new one when tested came back as weak so the supplier gave me a new one to eliminate it which was fully charged, and the new relay. Put it all back together and it started first time. Great I thought. I checked charging which was about 14.4v and was happy to drive to Essex. Used the bus all weekend with no problems. Started everytime with no problems and drove perfectly. I got back on Sunday at about 1600. Used it this afternoon to pick my daughter up from school no problems started fine. Then I went to start it again at about 1800 and it was dead. Checked the battery and it showed 12.6v. When I tried to start it the volts dropped to about 4v and nothing happened it was just dead. I also noticed that The remote central locking wouldn’t work, but works fine with the key in the door. Put the jump pack on it and it started fine. The only thing I have noticed now is the voltage coming from the alternator changes quit drastically, sometimes it is showing about 13.4v and other times it is about 14.5v. The change happens for no apparant reason - i haven’t suddenly put the lights on or off or anything else that could effect it, it just changes. Now my thought is that if the alternator is only working intermittently could it be that the battery isn’t charging enough therefore preventing it from starting. I also noticed that the cable from the alternator to the fuse box in front of the battery is getting really hot.

Could someone please let me know what is the standard reading for the alternator output on tickover should be without anything turned on, and any thoughts on the other things I have mentioned above.

I haven’t yet don’t the current draw test as suggested by twin slider but will give it a go tomorrow.

 

Mine shows about 13,8 V on idle and 14,4 V on throttle. You might want to replace the voltage regulator to eliminate that if the problem. It is an easy job.

 

Check the little water pump below the radiator isn't draining your battery.

Common fault usually caused by a sensor fault. Can be unplugged temporarily to test it.

 

So I have now replaced the voltage regulator in the alternator, and whilst doing so noticed that the cable back to the battery looked worn so replaced it as well. Turned the key and the bus started straight away. Result! Used it yesterday and this morning, absolutely fine. Went to go out this afternoon and it has happened again. When I turn the key there is a single click and then nothing. I connected the multimeter and the battery voltage was at 12.8 with the ignition off. When I turned the key to position one the voltage stayed the same, then when I turned the key to start it dropped to 2v. Again if I put the jump pack on it starts fine. I did this to start it, checked the charging which was at 14.4v, and went for a drive for about an hour. When I got back I turned the bus off, tried to start it straight away and nothing.

I’m not really in the position to pay an auto electrician, especially at this time of year, so if anyone has any further suggestions please let me know.

 

If the battery drops to 2 volts when cranking....guess where the problem is!!!!

"Again if I put the jump pack on it starts fine.".....so keep the jump pack on if you don't want to buy a new battery. :*

 

Looking at your later posts I would say that there is no need to do a current draw test.

As all voltages appear normal other than when the ignition is applied, looking for a bad earth or connection would be my first port of call.

In order of what I would look at in this situation

Charging Live to/from alternator. If it is getting hot there is probably a bad connection. Remove and clean/replace. Already done. Double check.

Earth from battery to chassis to gearbox. Remove and clean/replace. This means cleaning both sides and connection points

Starter connections. Including solenoid wire from ignition. Remove and clean/replace.

After you have tried these: if still the same.

Get a jump lead and make a good connection on the battery -negative and connect the other end to the engine or gearbox. Try starting. If starter clicks and jump lead gets hot there is an -earth issue. Could also be faulty starter motor.

Connect jump pack. If vehicle starts with jump pack then I would suspect faulty starter motor.

Accumulated dust from worn friction plate and DMF builds up in the starter motor

 

I am quite sure your starter motor brushes and or solenoid are worn. If you have a Bosch starter, the brushes are easy to replace. You buy a plate with new brushes already installed and you just fit it with the tube in place. After that you just discard the plastic tube.
If you have a Valeo starter, it is more complicated.

 

Thanks for your suggestion Indian. I have already fitted a new starter motor as the old one had seized up. I a starting to think that the motor might be faulty but I will try the other suggestions first and see what happens. Thanks.

 

In regard to the battery surely if it’s not up to spec I would have the same problem all the time, rather than the intermittent problems I have. As I said earlier the van did start fine after the repairs to the alternator I did yesterday, without the battery pack, and this is the second new battery I have put on in the last couple of weeks. Is it the case that you can have an intermittent fault with a battery? I will double check it tomorrow. I have searched the forum for info about batteries in case the one I have been supplied is not strong enough for the job, and there seems to be some suggestion that is should be a more powerful one than I have got. Mine is 71Ah with a CCA of 670A, and it seeems that most people with a 2.5tdi caravelle with electrics and aircon have an 85Ah with a CCA of 800A or bigger. But again if the battery wasn’t up to the job would it still be an intermittent issue?

I will also go over all the earth cables as suggested as well tomorrow and double check contact points etc, and the started motor. I guess if I can rule out the battery and earth cables as you have suggested then the starter is faulty and intermittently pulling too much from the battery.

Again thanks for the input/suggestions. If anyone has anything else they can suggest please let me know.

 

I had this same problem for months. Finally when the starter motor was dismantled, the brushes in the Valeo starter was only 5 mm long. Once in a while, the starter would fail and finally it failed most of the time. I have a post somewhere in this forum.

 

Your ignition switch can be faulty. To check for starter problems, pull out the plug and short the 2 thickest spade contacts and see if the starter spins. Keep the key in the lock while doing this.

 

hi you might have done this but check all your earth cables it could be a bad earth