Intermittent fault with starter button?

[Andy McGhee]

I could do with some help on this one, please.
I've just bought a 'new' Spanish-built F6. It has a starter button (just to the left of the gearstick); you turn the key in the ignition switch (Neiman) as usual, and then press the button to start it.
When I pressed the starter button this morning, there was absolutely no response; I had a look at the wiring and checked all the connections - there are more than usual, as the button has been spliced into the system.
I bridged the two connections on the button with a test lamp and turned the key; nothing for a while, and then the bulb began to light - annoyingly, not all the time; even when it came on, there was no response when I pressed the button.
And then, suddenly, it worked perfectly, and the engine started!
Am I missing something obvious? It seems to be a bad connection somewhere, but where?
Would really appreciate any help - both for diagnosis, and for instructions on how to revert to a Neiman-only solution !

 

[DAA]

For my experience the button will inform the starter relay to close. Find on the engine bay the wires and check, and on the key switch you will have an wire to feed the button.. and the problem could be on this connection, some poor terminals contact cause this.

 

[Andy McGhee]

I need some more help with this, please.
I thought I'd solved the problem - I checked all the connections I could find, and, as I said before, the van suddenly started; the starter button worked perfectly for a few days. I went for a long drive, stopped and started the engine perhaps a dozen times - everything fine. But I suppose the problem is that I don't know exactly what I did that 'fixed' it.
Today I had to fit a foglamp bulb in the speedo (without removing the steering wheel and speedo, a feat in itself...). I must've disturbed the wiring somewhere, because I'm back to square one. There are 12V at the starter button all the time; when I turn the key, the temp and battery lights work as normal, but when I press the starter button, there's absolutely nothing. As an experiment, I plugged in a brand new ignition switch (Neiman); the lights come on, but nothing at all happens when I turn the key to the normal starting position.
Would really appreciate some advice from the electrics experts on the forum!

Here's the back of the starter button.

 

[Andy McGhee]

And, of course, no sooner do I write this than the van starts...
I rechecked the connections to the starter motor (which I thought were fine); will reinvestigate tomorrow. Let's hope it's that!

 

[laxeian]

Could the starter switch itself be the culprit, the contacts within slowly burning out due to load rating?

 

[Andy McGhee]

Could the starter switch itself be the culprit, the contacts within slowly burning out due to load rating?

I honestly don't know, Ian - I'm pretty hopeless with electrics.
It's the first time I've come across a starter button like this; in a way, I'd rather have the conventional ignition switch system. One strange thing, though - when I tested the starter button with a multimeter, 12V showed all the time; when I put a test bulb across it, the bulb sometimes lit up and sometimes didn't. It'd be out and then suddenly light up.
But one ray of hope - unless I'm clutching at straws - I fiddled with the connections on the thin wire to the starter motor, and everything started working again. Will clean and remake those connections tomorrow and see what happens. Thanks for the message!
Oh, and by the way, what sort of specifications/load rating should a starter button like this have?

 

[laxeian]

The test with the bulb and 12v proves switch contacts are on the way out, intermittent or no bulb is your starting and not when pressing button, I have only fitted this type of switch to past cars that have been nigh on impossible ( or stupid cost) to get replacement lock sets, haven't had any experience on 4s but on column usually involves hammers,chisels and swearing to get the security nuts off of barrel to column to change barrel/lock mechanism so fitting a button is a way of getting round a faulty/ intermittent starting problem on the final start position of original key operation, the fault now being repeated by push button, button press start for older car should be of a suitable rating for the current draw to starter , switch fitted just doesn’t look like a high current switch, thats the quick fix, but really you need to be looking to see if you can change the electrical switch part of ignition lock separately or the unit as a whole with new/good used to revert to original format/wiring/key start. Suitably rated starter switches should be able to source (push button type) I have found at generic classic/race car part suppliers online in past.

 

[Andy McGhee]

Many thanks, Ian - I think I'm beginning to see some light (at least intermittently...). No hammers or chisels yet, but plenty of swearing!
I'm sure you're right; the best thing to do is to replace the ignition barrel and go back to the original system.
But if I replaced the starter button as a temporary fix, what amp rating would be right?
Thanks again!

 

[laxeian]

When I did fit in past iirc @4-5amp rated button push, this worked fine for over 3 years on Mk1 Transit without relays etc because of same type of problem with ignition barrel switch, believe it or not v early mk1 Ford Transit switches were unobtanium!

 

[Andy McGhee]

Thanks again, Ian - I really appreciate your help!
Have just replaced the thin wire to the starter motor (the connection at the starter motor was definitely wobbly). I unplugged the square ignition connection, plugged in a new ignition switch (Neiman), and the engine turned over as it should! When I did this yesterday, there was absolutely nothing. The engine now turns over as it should on the starter button, and a lamp bridging the starter button terminals stays lit... .
I'm tempted to leave things as they are for the time being - fitting the new ignition switch (normally a 30-min job) will be complicated, as the original wiring's been changed. I need to have a serious think!
Thanks again - any ideas always appreciated!

 

[laxeian]

Agree Andy, if its working as is now run with it , as you say your now at stage where returning to original involves tracing out non original mods to wiring to return to standard, this can be easy or hard depending on how hidden from obvious the modified wiring has been added, personally I taped it all up into existing looms when I did this to disguise mods, would’ve been a pig to return to standard because all ‘ new ‘wiring became invisible from original loom