1997 Trooper will not start in daytime

It shows between 8 and 11 volts on the dashboard meter, during the day, as soon as it cools off outside it starts the first try. Have replaced battery and 75 volt alternator, and starter relay.

More info?

When you turn the key, will the starter crank the engine and not ‘catch’? Or does the starter not turn the engine at all?

11 volts is pretty low. You should be seeing at least 12 before you crank the engine. Will the car start with a jump? BTW, I’m pretty sure you have a 75 AMP alternator, not 75 volt alternator.

It just clicks. When it first started a jump would start it but now it doesn’t help it still will not start.

I seem to remember that these older Troopers had a funky solenoid switch of some kind. You might want to check the switch. It will click when it goes bad but the starter will not engage.

After the engine is warmed up, will it not start? Or is it only related to the ambient temperature?

If I had to bet, I’d say it’s either the starter or solenoid (you usually have to buy both as an assembly), but it could possibly be the ignition switch, especially if the problem is only related to ambient temperature, not engine temp. When you only get a click, can you tell if it’s coming from the engine, or is it just a relay clicking inside the cabin? You might also try giving the starter a whack with a wrench or something next time it won’t start and see if that helps.

Just the temperature outside. I can get the engine hot and it starts fine as long as it’s cold outside.