BOTTLEDZ28

iTrader: (9)

Here is a wiring diagram for anyone wiring up a FAST ECU and stand alone harness. This shows how to wire up the fuel pump and fan relays to the ECUs output wires. This is a PDF file and I cannot convert it to a JPEG image, so if someone can please do to make it easier for others to see. FAST also told me that for those of use with dual fans to use a second relay. Split the control wire from the ECU so it goes to terminal 85 on each fan relay. Supply the second relay with its own battery input (30), ignition input (86) and fan output (87).



Terminal 86 needs to have power on it for the relay to work (the ECU supplies the ground). It can come from just about anywhere – even straight from the battery. But if it comes from a source that is only hot when the ignition is on (run and start), that means there is no way the relay can accidentally be turned on when the ignition is off.


I hope this info helps anyone out. I was in jam with this wiring and now I got it figured out and will pass the infoon to you guys. I am rewiring my these circuits from scratch with larger gauge wire and so that I can hide more wiring under the dash versus under the hood.

DJ406

I figured you knew how to wire a relay when you said you wired the whole system up.or I would have sent you some relay wiring info earlier. That pdf shows the xfi box but the basic relay wiring is all the same. glad you got it figured out

Have you replaced the fuel pump?if so what pump did you use. are you using an XFI or the old system.

Dj

BOTTLEDZ28

iTrader: (9)

FAST just sent me that diagram. I believe that diagram is for both XFI and Classic style boxes. Either one though, its still the same layout. I am using the older ECU BTW. I am running a Holley fuel pump which i installed a few years but it hasnt got much use since i havent driven my car much due to other things being done on it. Right now, my only dilema is getting the wiring all figured out. I gotta figure out where I am going to wire in all these relays to the cars 12 volt source. I do not want them wired in for constant power so I gotta see what going on with the fuse block for spare locations. I have about 5 relays that I want to install in the car and Im not sure if I can wire them all up to one IGN/ACC fuse slot. Im working on that info now though.

DJ406

you should wire the fuel pump and the fan relay directly to the battery with a fuse at the Bat.

BOTTLEDZ28

iTrader: (9)

Yes they will be wired directly to the battery. all my relays will have a wire from terminal 30 going to the battery. I justhave to figure out where the wire from terminal 86 will go. It says to send it to a switched 12V source. I assume that means the fuse block but I have 2 in there now and I need to find a home for 5 more now. Im not sure if I can splice them all into one connector to trigger the relays

DJ406

you could take several wires together and use just one connector if it was just feeding relays. the current drain is pretty low for that use.

BOTTLEDZ28

iTrader: (9)

you think a 2 or 3 amp inline fuse wilwork near the fuse block?

DJ406

probably but that sounds a little low for several relays. Id use a 10 amp fuse for starters (not that it will draw that much)

fastride90

i need help on a 1990 camaro how can i power up the fuel pump
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thanks