1998 GMC Sonoma won't start
We've replaced the starter, relay and the battery
and alternator are new. Fuel pump is good. No
clicking, all lights come on. Does not dim when
turning key. Just won't start. What can I check
is the starter relay clicking when you turn the key
So I am having a similar problem with a cherokee. I suspect the flywheel but won't be sure until this weekend. You may also try the neutral safety switch. Just to be sure. I turn the key while shifting from park to drive. You should hear the click from the starter in park and neutral. If not, that may be your problem.
The relay could be week . Even though you here it click it may not be making a good connection inside. Also as Jacaonod wrote could be it is not all the way in park. Try starting it in nutral.