AM2 Fuse Tripped

1999 Toyota Tacoma
3RZ 2.7L Automatic
2 coil ignition system
176000 miles

So I was waiting in the turn lane at a stop light for the green arrow. When the arrow turned green, I hit the gas and my truck died. I was not able to restart it, and 3 guys helped me push my truck through the intersection into a parking lot.

After getting the truck towed to a local shop, they discovered that the AM2 30A fuse under the hood was tripped. They replaced the fuse and the truck started right up. Obviously something caused this fuse to trip? The mechanic tried shaking the wiring harness that feeds the ignition coils and injectors and the truck kept running. I actually drove it home just fine.

My question is, what could cause this fuse to trip. So far I have the following to check

• wiring to ignition coils
• wiring to injectors
• shorted injector?

I will be pulling the valve cover off tomorrow to adjust the valve clearance, so I will have easy access to the harness that feeds the injectors and ignition coils. I have the FSM and wiring diagrams. Is there anything that I should look for specifically? I got a few extra 30A fuses just in case it trips again.

 

On a potentially related note, my rear diff lock has stopped working. Pushing the button does not turn on the indicator on the dash. Keep in mind I added the factory locker to my truck, but I wired it in to use the factory circuits as much as possible. it does have its own separate wire harness though.