Starter relay or no starter relay, Been reading up for an hour and still don't know!! Options

[David Stowers]

On two occasions recently on pulling onto my driveway after a long journey my car won't restart after turning off to unlock the garage door. Luckily I can then just push the car in but with a European tour booked in the summer I'd like to sort the problem.
When I get back in after opening the garage the lights on the dash dim when I turn the key to start but there is no click. 20 minutes later it will start right up. Is this the problem that will be solved by a hot start relay kit or just a good old fashioned sticky solenoid? I'd rather do just the relay or just replace the solenoid so which is it?
Thanks guys

[Tom]

A relay is not necessary, however, if one is not used, you will have to replace your ignition switch sooner than you should have to. Why? A simple test will explain all, even to the electrically challenged!
Find an old starter that has a good solenoid. Hook it up to a battery using nice clean new spade lugs. Hook up the negative to negative battery post , then touch the new spade lug to positive battery post. The solenoid should energize. Now remove the spade lug from the positive battery post. See the nice spark? Now look at the spade lug where it came into contact with the battery positive. See the black mark? That is what happens to the contacts in your ignition switch every time you start your car! Carbon from the arc flash. If you had a powerful magnifying glass and looked at the spade lug, you would see pitting also. Now if you have a bosch relay, do the same test. Arc is so small it can't be seen. Relay contacts are engineered from a viewpoint to extend the contact life by using special allows that resist pitting and arcing.
A relay , if and when it fails, is much easier to change that the ignition switch. I have been using this relay for years without a failure. Cost about $2.00. While this one is Chinese, there are others out there that will work just as well.
Tom