very intermittent hot start problem

[MATTT]

Now the bus is tucked away in the carport,I've decided to have a go at fixing it
It has only showed up twice so will be tough to track down
It clicks the solenoid and won't spin over ,tried a jump battery still the same ,both times when it was hot

Before I could get under to give it a whack and check the terminals on the starter,it cured it self and hasn't done it again since
I've read either bad wiring,a worn bush on the end of the starter pinion, or a duff motor
Are any of those 3 things common?
Cheers
Matt

 

[Resto-raider]

This is the hot start problem. It is usually fixed by installing a 'hot start relay'.
For example http://www.justkampers.com/shop/141951253b-hot-start-relay-12v-j12928.html

 

[MATTT]

Hi
I read that ,it does seem like a bit of a bodge?,as surely if the wiring and ignition switch is working correctly then an extra relay isn't needed
Or was this always a weak point from new?
Cheers

 

[jonboylaw]

You have 40 plus years of corrosion in the terminals that is going to raise the resistance on the solenoid connections, plus all the current through the ignition switch which will have dirty contacts so likely the voltage drop is more than it was ever designed for. You could rewire the starter circuit and put a new ignition switch in (gamble on the quality) or use a relay to off load the current through the circuit and make use of what you have. I fitted the relay....


Sent from my GX64 SatCom phone using Tapatalk

 

[MATTT]

The ignition key is the only 1 that's different to the rest of the van
I wonder if that was changed because of this problem
I guess the wire from the ignition switch to the starter solonoid is in a loom not just a single wore running back from the switch?
As I would be able to run a new wire easily if it was on its own

You fitted a relay was that for the same problem as mine?

 

[MATTT]

The ignition key is the only 1 that's different to the rest of the van
I wonder if that was changed because of this problem
I guess the wire from the ignition switch to the starter solonoid is in a loom not just a single wire running back from the switch?
As I would be able to run a new wire easily if it was on its own

You fitted a relay was that for the same problem as mine?

 

[jonboylaw]

Mine was pre-emtive to reduce the current through the ignition switch to avoid it burning out over the long term.


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[Happystamps]

I fitted one to remedy this issue- this was after the "intermittant" became about 50/50! It's been fine for three years or so now.

You're right though- technically it is a "bodge" in that it doesn't sure the issue. If you're the kind of guy that sorts stuff properly (and good for you) then I'd disconnect the battery and measure the resistance of the circuit to the starter at various points to track down any high resistance areas.
so that's earth strap---battery negative. and SEPERATELY! battery positive---- light switch-----ignition switch----starter solenoid.

I'd also then install a hot-start relay anyway. VW should have fitted them from new, they only didn't in the name of cost.