Bad wiring on the starter motor?

[murrayslinn]

Hi all,
Have had "Mimi" for the better part of a year and done about 8000 miles. Few little bits and pieces to fix along the way but some good long trips to France and Switzerland etc. on my way home the other night my lights began to dim, the temp gauge and fuel gauge started to decline and the stereo (directly powered by the leisure battery) started flashing and flickering etc. Eventually the lights ran right down and I pulled over to have a look. Once i had pulled over the engine was idling high and not very consistently.

Baffled as no fuses had blown. The main battery had a full 12v and when the ignition was turned on the instrument lights had full power but the starter was dead.

As per standard the only time she breaks down the van was packed with stuff so unloaded onto the roadside I couldn’t see anything as a giveaway. The tow guy (grumpy for having a job) had a look and burned himself on the starter motor. Then said that the whole thing was wired badly. The alternator was directly wired to the starter motor and they should be independently wired to the battery. so the reason for breaking down was that the starter motor was running full time as the alternator was feeding it?.

So I’m guessing that the starter motor is knackered, replace that and rewire the whole setup. I’m happy with tinkering with this stuff but would like some thoughts on this.

Any ideas?

I would love to provide a pic but I’m away from the van for another week.

Thanks

[Mocki]

Firstly you don't give us any clue what van you have, what engine or year.

So, assuming its petrol, the tow bloke was talking outa his a***! The alternator is connected to the started motor as standard, to connect to the battery up under your seat. The starter will only be running if its getting a signal from the ignition switch to the solenoid,, or if its malfunctioning.

[California Dreamin]

Given that both Leisure and starter batteries are connected together whilst running then the symptoms point to a non charging alternator and the ignition and electrics generally running directly off the 'batteries' in this case, until running flat..well, to a point that effected the ignition (too lower voltage to produce a sufficient spark).
At this point there appears enough power for things like dash lights but not enough to actually re-start the vehicle.

I would be looking at the alternator first (see if you are getting 13.9 - 14.2 volts with the engine running) then all the main feeds/earths to the alternator/battery/starter/body etc. Does your ignition light come on?

Martin

[murrayslinn]

Thanks guys,

She is a 1983 1.9 watercooled petrol with a DG engine , not the original i would think.
I did wonder if the tow guy was full of it, he wasnt really that interested in being there to be honest any was a grumpy bast@&*.

The strange thing is that the ignition lights came on and internal lights etc worked but absoultly no start, even when hooked up to the tow truck for a jump. Plus the meter showed 12V on the battery. Also the alturnator was checked a few months ago and was still going strong.

So does that mean that the starter motor could be running all the time due to a short in the ignition?

If i can get her running ill test the alturnator and main wiring and go from there.

Cheers

[itchyfeet]

12V is a pretty flat battery, a healthy battery should be 12.7V or slightly more.


That said I have started with a battery lower than 12V so it maybe you have two faults, a bad connection on the starter trigger wire / ignition switch which was OK with a good battery but now won't work with a flat battery, get a battery charger on in for 12+ hours.

you'd know if the starter was running it's very noisy so I'd say no


If once charged it still won't start you can bypass the ignition wiring by shorting the trigger connection on the starter direct to 12V, easiest/ safest to make up a cable to do this.

as said clean up earths while you at it.

another possibility is the numpty recovery driver who had no clue what he was talking about as knocked the trigger wire connection off

[murrayslinn]

Ok Great, that sounds more reasonable. I did think that his comments were a bit strange as she normally runs pretty well.
If the battery was flat would that explain erratic ideling once i pulled over?

Thanks all for your help

[California Dreamin]

12 volts is below 50% charged, see:



But should still be enough to start....although batteries do 'rally' once you've turned everything off, what could have been mid 11 volts then creeps back up slightly.
I would definitely be checking the trigger spade connector (standard 6.3mm female on the solenoid)
But what ever happens the batteries (both) are going to need a good 12 - 16 hours each on a charger to get them back up to 100%

Obviously you need to find our why they are draining....could be a straight regulator bush pack fault but broken earths or main feeds could also cause the same problem.

Martin

[murrayslinn]

Thanks again,

The one thing that still dosent make sence is why it didnt start with a jump, not even turn over

[Oldiebut goodie]

If once charged it still won't start you can bypass the ignition wiring by shorting the trigger connection on the starter direct to 12V, easiest/ safest to make up a cable to do this.

as said clean up earths while you at it.

another possibility is the numpty recovery driver who had no clue what he was talking about as knocked the trigger wire connection off