Fighting through wiring issues. One quick question on Permanent Hot to Pin 1 of the Mustang A9L. Do you just connect (add) the Miata Blue/red wire to the pin one wire or do you cut the ford wire and attach the blue/red to the computer. If I just attach the Miata permanent hot, the fuel pump does not shut off for some reason. Any ideas?

Thank you for any input anyone has.
James

 

I did away with all of the Mazda wiring. I wired the constant + via a fusible link to the firewall mounted starter relay. I also used the Ford fuel pump relay as well as the inertia switch. Get a Ford wiring book & use it instead of all of the "grafting".

 

Bolt the Ford constant hot eyelet with its fuse link to the 10mm bolt that holds in the main power fuse in the Mazda under hood fuse box.

-Jason

 

Thanks Jason, now my stupid question, where is ford constant hot eyelet. i looked at the harness and wiring diagrams in Martin's guide and not sure what you are referring to. thanks again!

 

The main power eyelet should be located at the coil plug end of the harness. It's a rather large eyelet that is attached to a flimsy blue wire called a "fuseable link". The fuseable link is attached to large gauge wire that is ether bright yellow or black with an orange stripe depending on year.

It's possible that whoever pulled the harness sniped the eyelet off when they pulled it from the car. I see this about half the time. If that is the case just find that main power wire and solder a waterproof fuse holder to it with a 30 amp fuse. To that solder a new eyelet and you're good to go. Locate all this about 6 inches from where the harness enters the engine bay so that you're right by the fuse box.

-Jason

 

Thanks Jason. I found it. That is the eyelet that Martin's book directed to cut off and insulate, which I did. If you have a few minutes can you explain the difference. Others may have the same question. As always, I appreciate your HELP!

 

The wire Martin has you tap into to supply 12 volt constant power is not nearly heavy enough to power the entire engine electrical system. I pull the Mustang's original eyelet back to right by the Miata power distribution box (essentially the same thing as the Mustang's bunch of connections on the coil) and then use the slack I know have behind the firewall to start building my fuel relay circuit.

While we're on it, don't tie the 12 volt keyed hot to the HEGO power wire. Tie the HEGO power wire to the red/green coil power wire and then tie that to the miata white/red keyed hot.

And build a fuel relay circuit, don't use a switch and a dummy relay.

-Jason