Rep Power: 0

I'm curious as to what system Fuse 20 supports? When I engage the starting circuit it blows. I pulled the starter and it checked good. Check all starting circuit relays and they are good. Your insights are appreciated.

 
Rep Power: 185

I'm assuming you have a coupe/sedan and it's not a GX for this post.

If you have a Chilton manual, page 12-35 shows the starting and charging system circuitry.

Fuse 20(40A), which goes the the ELD(under hood fuse box) and then through fuse 19(80A) to the battery and then to the starter solenoid.

Fuse 20 is the ignition 1 fuse and fuse 19 is the battery fuse.

If you hadn't pulled and tested the starter, I would have suspected it first, but you may have a wiring problem. Something shorted to the chassis causing the fuse to blow everything time.

The circuit is fairly simple in the Chilton manual on page 12-35. I would start by pulling fuse 19 and 20 and putting a meter in fuse 20's legs and checking the legs to ground, which should all be open if the ignition switch is not in the start position. If there's a short going up to the ignition switch and the switch isn't in the start position, then it's either the wiring to the switch or the ignition switch itself.

Good luck.