I have a 90 crx hf that won't start when key is in the on position, but can hear main relay clicking several times over and won't stop main relay is good because it will crank my integra no problem need help please.

Does the Check Engine Light stay on when the ignition switch is turned to ON (Position II)?

Yes but I know it isn't the ecu cause it did that with two others that I know work I'm at lost when it comes to this, never had a problem like this one.

The problem is with the ACG (ALT) (S) fuse, in the under dash fuse/relay box; ECM; main relay; or the ignition switch. Perform tests in that order.

Thanks man that fixed it it had to blown fuses under the hood fuse box thanks again

Good job.