HOT WEATHER - car wont start (no noises at all)

[hornetcarp]

i've spotted a pattern to my non starting problem.

it seems to do it when the weather is hot, when the car has been in the sun for hours.

when i say none start i mean nothing at all no cranking, solenoid clicking etc.

i'm pretty certain it's the ignition switch or something similar.

would it make sense that the hot weather/strong sunshine (hence very hot cabin temp) is causing some metal connection/wire to expand and therefore loose electrical connection????

anyone have experience of this sort of phenomenon???

thanks people

[BobProperty]

Ignition switch or aftermarket alarm are the favourites IMHO. See previous thread https://www.vwaudiforum.co.uk/forum/s...ad.php?t=70558

And yes I have experienced it, it was the ignition switch on our car. The fun bit is getting the collet off the steering column.

[hornetcarp]

right i think it's definitely the ignition switch, and only does it when the weather is hot

never does it in the morning when it's nice and cool.

is it normal for the key to get very hot when trying to start it repeatedly (and failing) due to a bad switch? i guess it shorting?

right i had ago at starting using the 'jump' method using a jump lead to connect battery +ve direct to starter solenoid connector. after a number of tries got it to fire and run, is it normal to get plenty of sparks?!?!

i think because of the sparks i was breaking the connection before it could fire??

[BobProperty]

is it normal for the key to get very hot when trying to start it repeatedly (and failing) due to a bad switch? i guess it shorting?

Can't answer that one, never noticed when ours did it.

right i had ago at starting using the 'jump' method using a jump lead to connect battery +ve direct to starter solenoid connector. after a number of tries got it to fire and run, is it normal to get plenty of sparks?!?!

i think because of the sparks i was breaking the connection before it could fire??

Er, yes because you are putting the starting amp draw down your jump lead. Did it get hot by any chance? The trick is to use a length of wire to put 12v to the solenoid trigger terminal, not the large current terminal that goes straight to the starter motor!

If you are going to replace the ignition switch then there are a few things to be wary of. Remember to centre the steering wheel before you start taking things apart. Disconnect the battery, because you have to take the airbag and steering wheel off. Most other stuff "undoes" in a straightforward manner from what I can remember until you get to the splined collet that is on the top of the steering shaft. Allegedly, you can use a gear puller type tool to remove it. Allegedly, my local VW dealer only manages to get their puller to work about half the time. I had to cut mine off and buy a new one. I also can't remember if you have to drill out a bolt on the actual ignition switch holder as there is a shear bolt somewhere in there IIRC. And I can't remember if you get a new one with the ignition switch or whether it's seperate, I think it's a seperate part.
I'm sure I haven't covered everything in there so don't go rushing in just based on my post.

[hornetcarp]

Can't answer that one, never noticed when ours did it.


Er, yes because you are putting the starting amp draw down your jump lead. Did it get hot by any chance? The trick is to use a length of wire to put 12v to the solenoid trigger terminal, not the large current terminal that goes straight to the starter motor!.

no didn't get hot just abit of sparking which made me jump each time and i think that caused me to move slightly so i wasn't getting a good connection, hence it took a few attempts to fire up??

it was the solenoid trigger terminal i was connecting the battery (+ve) directly to...i think?? where the plastic connector pulls off (has a thin red and black wire going into it). i wasn't touching the bolted on thick cable on the starter?

If you are going to replace the ignition switch then there are a few things to be wary of. Remember to centre the steering wheel before you start taking things apart. Disconnect the battery, because you have to take the airbag and steering wheel off. Most other stuff "undoes" in a straightforward manner from what I can remember until you get to the splined collet that is on the top of the steering shaft. Allegedly, you can use a gear puller type tool to remove it. Allegedly, my local VW dealer only manages to get their puller to work about half the time. I had to cut mine off and buy a new one. I also can't remember if you have to drill out a bolt on the actual ignition switch holder as there is a shear bolt somewhere in there IIRC. And I can't remember if you get a new one with the ignition switch or whether it's seperate, I think it's a seperate part.
I'm sure I haven't covered everything in there so don't go rushing in just based on my post.

apparently you can avoid that splined collar thingy by unbolting the column from down by the pedals and pulling the whole thing out?!?!?