What exactly does the opening circuit relay do or control ?

 

The Circuit Opening Relay controls the power to the fuel pump. Which is why it's sometimes refered to as the Fuel Pump Relay.

http://personal.utulsa.edu/~nathan-b...96circuito.pdf

 

Thanks Mudhippy for the reply, my fuel pumps operating fine so I can eliminate that relay as the problem, Thanks........

 

What's the problem?

 

Hey RAD 4Runner,I went to start my Runner and heard a clicking coming from my EFI relay, Found the 15 map EFI fuse next to it blown, swapped it & just turned the ING to the on pos and it blew agian, Cked the obvious wiring & found no problems that I could see, used my meter to ck countinuity on that fuse block & it sounded a dead short, Just trying to figure out were to start, Wiring issues scare the $&@! out of me...

 

Common cause of EFI fuse blowing is an O2 sensor wire that has fallen onto the exhaust melting the insulation and causing a short, either to the exhaust (ground) or the two heater wires for the sensor touching each other.

 

4Crawler, Thank you for the advice, that seems to be the common issue being said , I plan on diveing into it this week, figure I might as well look into a small oil leak etc. etc. while I'm at it. Thanks agian.....