The only way I can think of to fix this is to add another relay to break the connection for resistor. But that's no good because there won't be any power to pump when switching between 8V and 14V....

 

After all this thinking, I come back to this. For safety reasons, I like the left relay nearest the battery to avoid running a live big positive wire to back of car. And right relay near pump (trunk?). Just need a light wired to right relay and Relay #3 to let me know when either relay isn't working so I know when to replace.
Nice job Biggiesacks

 

i never redrew it, but the pink wire needs to be hooked up to a 12v switched source instead of pin 87a of the right relay. Basically for the same reason of getting stuck, however you only need to do that on the left relay if you want to separate them.

 

Like this:




So basically as the right relay mimics the operation of relay 3, the left relay mimics the operation of relay 1.

 

if you wanted to you could even tap the 2B-W wire (after the fuse) that provides power to relay 1 and relay 2 coils to power the left relay coil. the 7.5A fuse should be plenty for one more relay, and its already under the hood where you want to put the left relay. That wire already goes to the ignition switch, its for this purpose, and its right there.

 

Can ECM Relay #2 handle your left relay instead of using a chassis ground?

 

If we tap into any of the OEM Relay power wires, I would think it already lost voltage and won't give us 14V. Also, aren't they 14 awg?

 

I can't decide.
Can you disconnect your CAS and crank engine and see if you are getting fuel into engine? I suspect you will because your left relay won't turn off like OEM Relay #2 and will power fuel pump.

 

no the fet in the ecu that controls relay 2 is not strong enough for any more relays, I think MrFred said he burnt that fet out attempting to do that. The Fet that controls relay 3 is different and much beefier.

 

Thats a good point, im not sure if it would pull relay 3 or not, but i haven't wired mine up that way yet so I couldn't test it. I still have mine setup like in my original with 86's tied to 87a. When my car has died during tuning and cold e85 starts I have either just restarted immediately or reached under my seat to the distribution block I have under there and pulled the fuse (hence the bit about installing a button). I left it that way because ultimately I want to make a PCB with a dual P-channel mosfet chip to wire into the ecu so i could drive both relays from the ecu without frying that weak mosfet. Its still on my todo list. I hadn't considered that bit about having it hooked up to switched 12v causing the pump to get voltage without an ECU signal so good catch.

 

Its only tapping it to power the coil of the relay, that pulls like 300mA or something, and it will operate down to a pretty low voltage. The 7.5amp fuse on that line is more then plenty to power the 3 relay coils. That line is specifically for powering the coils of the relay not the devices the relays switch power to. I would expect all 3 coils to draw an amp, maybe 2 so no worry of voltage sag on a 14 gauge wire. Like you pointed out though, thats a flawed implementation because you don't have the ecu to interrupt the signal.

 

Do you have fuse box schematics?

 

let me see what i can dig up

 

 

lol goes to show how long its been since i looked at these. Gluck getting to that connection after the fuse lol....looks internal to the junction block


EDIT: actually it looks like you could grab it at C-210 pin 1. Again though you probably wouldn't want to do it this way because of the issue you pointed out.