Anyone have access to wiring info?

[fumanchu182]

Pin A is DB/OR and I don't think that changed on 2015-2016.

https://www.hellcatforum.org/threads/live-action-from-fumanchu182.6592/page-49#post-266504

What I used for operating my normal pump in the car.

 

[Speedy!]

OK, I've looked at everything and understand how the fuel system and FPCM work. Here's what I'm doing.

The 2.7L blower making 20psi and the billet end plate from SDG is maxing out the 285 pumps in my dual drop in fuel system on E85. Injector duty cycle, pulse width, and all the other things are fine but I'd rather have a bit of overhead on fuel system.

I picked up a dual output JMS Bap from @Jon-MooredPerformanceLLC. They put one in @vortecd car and it's doing the business. I'm not a huge fan of a bap as usually they're put in as a band aid, but if all other components in a fuel system are within range without one and you just need a bit more on the pump(s) then I think the JMS is a good option. It's super simple and is connected to the throttle position sensor so it's only providing additional voltage when you're at WOT. You can also configure it to the amount of extra voltage it gives, so you can give just enough extra.

The problem is there's something funny with the way the dual pump drop in systems are wired to the second FPCM that is causing my pumps to run non stop after the car is keyed to "run". It should just prime and stop. Keying the car back "off" the pumps and JMS still keep running. JMS support has been good to work with but claim this is a known issue and they don't have a solution at present. Somehow Jon and Jim got it to work in his car, but even JMS has no idea how that's possible.

SO, I've been looking at re-wiring the JMS pigtail on the second FPCM to see if I can resolve the issue. Looking at the Y harness going from FPCM 1 to FPCM 2 on this drop in fuel system it's super simple only using a relay and a "signal" to keep the two fuel pumps in sync voltage wise. The JMS pigtail is setup for a Redeye or Demon that has two factory FPCM harnesses. My thinking is to remove some of the pins in the JMS connector on FPCM 2 so that it only has what the drop in system has connected.

I was hoping maybe the JMS pigtail was wired to get +12V source from something other than the fuel pump relay and I could simply move that wire to the proper pin in the connector, but best I can tell it is actually getting input from the fuel pump relay, so it's something else making the pumps and JMS continue to get voltage after key off. It's back feeding somehow.

 

[Diboblo]

PM sent.

Sent from my SM-G666 using Tapatalk

 

[covidcommander]

OK, I've looked at everything and understand how the fuel system and FPCM work. Here's what I'm doing.

The 2.7L blower making 20psi and the billet end plate from SDG is maxing out the 285 pumps in my dual drop in fuel system on E85. Injector duty cycle, pulse width, and all the other things are fine but I'd rather have a bit of overhead on fuel system.

I picked up a dual output JMS Bap from @Jon-MooredPerformanceLLC. They put one in @vortecd car and it's doing the business. I'm not a huge fan of a bap as usually they're put in as a band aid, but if all other components in a fuel system are within range without one and you just need a bit more on the pump(s) then I think the JMS is a good option. It's super simple and is connected to the throttle position sensor so it's only providing additional voltage when you're at WOT. You can also configure it to the amount of extra voltage it gives, so you can give just enough extra.

The problem is there's something funny with the way the dual pump drop in systems are wired to the second FPCM that is causing my pumps to run non stop after the car is keyed to "run". It should just prime and stop. Keying the car back "off" the pumps and JMS still keep running. JMS support has been good to work with but claim this is a known issue and they don't have a solution at present. Somehow Jon and Jim got it to work in his car, but even JMS has no idea how that's possible.

SO, I've been looking at re-wiring the JMS pigtail on the second FPCM to see if I can resolve the issue. Looking at the Y harness going from FPCM 1 to FPCM 2 on this drop in fuel system it's super simple only using a relay and a "signal" to keep the two fuel pumps in sync voltage wise. The JMS pigtail is setup for a Redeye or Demon that has two factory FPCM harnesses. My thinking is to remove some of the pins in the JMS connector on FPCM 2 so that it only has what the drop in system has connected.

I was hoping maybe the JMS pigtail was wired to get +12V source from something other than the fuel pump relay and I could simply move that wire to the proper pin in the connector, but best I can tell it is actually getting input from the fuel pump relay, so it's something else making the pumps and JMS continue to get voltage after key off. It's back feeding somehow.

View attachment 86139

Maybe need a diode on it?

 

[Speedy!]

A diode is one possible solution, but I'm wondering if one of the extra wires in the JMS pigtail is carrying the voltage back and simply removing the un-needed wire(s) solves the problem. The JMS pigtail that plugs in to the FPCM has wires in all 8 pin locations. As you can see above the dual pump system wiring only has relay, signal, and output. Super simple. The JMS pigtail is a straight pass through of all connections except the fuel pump +12V input and the output to the pumps. Those branch off, go through the JMS, get extra voltage, then back to the FPCM.

 

[oilburner]

OK, I've looked at everything and understand how the fuel system and FPCM work. Here's what I'm doing.

The 2.7L blower making 20psi and the billet end plate from SDG is maxing out the 285 pumps in my dual drop in fuel system on E85. Injector duty cycle, pulse width, and all the other things are fine but I'd rather have a bit of overhead on fuel system.

I picked up a dual output JMS Bap from @Jon-MooredPerformanceLLC. They put one in @vortecd car and it's doing the business. I'm not a huge fan of a bap as usually they're put in as a band aid, but if all other components in a fuel system are within range without one and you just need a bit more on the pump(s) then I think the JMS is a good option. It's super simple and is connected to the throttle position sensor so it's only providing additional voltage when you're at WOT. You can also configure it to the amount of extra voltage it gives, so you can give just enough extra.

The problem is there's something funny with the way the dual pump drop in systems are wired to the second FPCM that is causing my pumps to run non stop after the car is keyed to "run". It should just prime and stop. Keying the car back "off" the pumps and JMS still keep running. JMS support has been good to work with but claim this is a known issue and they don't have a solution at present. Somehow Jon and Jim got it to work in his car, but even JMS has no idea how that's possible.

SO, I've been looking at re-wiring the JMS pigtail on the second FPCM to see if I can resolve the issue. Looking at the Y harness going from FPCM 1 to FPCM 2 on this drop in fuel system it's super simple only using a relay and a "signal" to keep the two fuel pumps in sync voltage wise. The JMS pigtail is setup for a Redeye or Demon that has two factory FPCM harnesses. My thinking is to remove some of the pins in the JMS connector on FPCM 2 so that it only has what the drop in system has connected.

I was hoping maybe the JMS pigtail was wired to get +12V source from something other than the fuel pump relay and I could simply move that wire to the proper pin in the connector, but best I can tell it is actually getting input from the fuel pump relay, so it's something else making the pumps and JMS continue to get voltage after key off. It's back feeding somehow.

View attachment 86139

if you disconnect the relay will the pumps stop??

 

[oilburner]

if so I think I may have a solution.

 

[Speedy!]

I haven't tried unplugging the relay directly but any break in power to the JMS shuts it all down. JMS gets power from both FPCM modules through a simple 2 pin connection, +12V in then sends that out as an increased voltage you specify to the pump. Unplugging either of those shuts everything off.

One of these plugs directly in to each FPCM then the 2 pin white/red connectors go to the JMS box. Red is +12V and White is output to pumps. As you can see everything else is straight pass through form harness to FPCM.

Right now I just have the JMS connected to one FPCM and it's working fine but only on the one pump. Putting it on both will be better as I can give each pump a little voltage instead of all the increase on just one.

 

[oilburner]

I haven't tried unplugging the relay directly but any break in power to the JMS shuts it all down. JMS gets power from both FPCM modules through a simple 2 pin connection, +12V in then sends that out as an increased voltage you specify to the pump. Unplugging either of those shuts everything off.

One of these plugs directly in to each FPCM then the 2 pin white/red connectors go to the JMS box. Red is +12V and White is output to pumps. As you can see everything else is straight pass through form harness to FPCM.

Right now I just have the JMS connected to one FPCM and it's working fine but only on the one pump. Putting it on both will be better as I can give each pump a little voltage instead of all the increase on just one.

View attachment 86151

I`m assuming relay pulled would shut them down, if so instead of relay ground going straight to ground you could use a second relay to control the ground. second relay would work the same way the auto shut down relay works, it would only be energized when ecm sees ignition. you would have to locate a circuit that is dead with key on eng off. during crank an engine running sec relay would close ground circuit for primary relay an open ground when no ignition an pumps would shut down.
it would also add some safety to the circuit.

 

[oilburner]

I said it would only be energized when it sees ign. I meant to say RPM. or when key is first turned on.

 

[oilburner]

your second relay that controls ground for first relay could get its coil side power from tapping into fuel pump relay or auto shut off relay in trunk fuse/relay panel. pin 87 on either
very simple easy, safe circuit to wire.

 

[Speedy!]

I understand what you're describing. What does the auto shut down relay actually do?

I'm going to try removing the unused wires in the JMS connector first and keep that 2nd relay as an in my back pocket option.

Looking at the dual pump harness:

FPCM 1 connector has this configuration:
PIN A +12V from fuel pump relay output as described in the wiring diagram. The external relay for the dual pump system is also activated from here.
PIN B goes to PIN B on FPCM 2 connector. This is the PWM Control and makes sense to keep both pumps in sync with the variable voltage they see. This wire is purple.
PIN C NO CONNECTION
PIN D I believe this is the +12V out to fuel pump 1
PIN E Ground
PIN F PWM feedback this wire is blue. This also makes sense as this is the feedback loop back to the PCM telling it the commanded voltage is being seen.
PIN G NO CONNECTION
PIN H This is another connection to fuel pump 1, the wire is black so likely the fuel pump ground or this is used to complete the pump circuit.

FPCM 2 connector is super basic and has the following configuration:
PIN A +12V from external relay shown in the harness above.
PIN B Purple wire from FPCM 1 and used to keep the pumps in sync I believe.
PIN C NO CONNECTION
PIN D fuel pump 2 +12V
PIN E Ground
PIN F NO CONNECTION
PIN G NO CONNECTION
PIN H another connection to fuel pump 2, the wire is black so likely the fuel pump ground or this is used to complete the circuit.



So there's several things not connected to FPCM 2 on the dual drop in harness, but the JMS has everything wired in theirs. I'm going to try removing the wires on each JMS harness that have no connection and test.

If that doesn't find the problem then it'll have to be something internal to the JMS control box and I'll have to add a relay or diode somewhere.

 

[oilburner]

auto shut down relay will cut power to several circuits if ECM does not see crank signal or RPM.
sort of a safety relay in the event of an accident.
sure you have noticed if you push start without your foot on the brake pedal the ecm will allow fuel pump to run for a few seconds. if ECM does not see crank signal ASD relay will shut things off.

 

[Speedy!]

Well, de-pinning the JMS harnesses to match the dual drop in system FPCM connectors didn't work. I was pretty confident in that so bummer.

It must be something to do with how JMS handles the voltage input/output from the Fuelmax and how the second FPCM is connected. As a hail marry I'm gonna see if I can easily move the +12V on/off trigger wire going to the second fuel pump to the factory fuel pump relay. Theory is that the second pump will only be active when the factory fuel pump is, and that'll remove that trigger from the FPCM connector.

If that ends up being a PITA or I don't like how the wiring is secured in that configuration I'm just gonna run it on a single pump until a solution is found. You'd think someone would have solved this by now.

 

[Speedy!]

Well, I'm starting to miss the good o'l days when fuse block was just a fuse block I thought I could just hookup the 2nd pump relay trigger wire to the fuel pump relay, but with the way the pins are setup I'd almost have to fabricate a pin tap for that.

SO, I thought I'll just connect it to the fuel pump fuse, with a fuse tap. Well, that's a special fuse type called "JCASE" and the fuse itself is female pinned. The normal fuses in the trunk distribution box appear to all continue to get power for some time after the car is keyed off (like the radio, etc). I'm gonna have to poke around a bit with a DMM to see if any of them shut down with key off and only power on when car is running.

Man this plug and play deal turned in to a project LOL.

OH, and if I had looked closer I'd have known de-pinning the JMS pigtail wouldn't work. It seems the dual drop in connectors to the FPCM 1 only use 4 pins. A, B, E, and F. That's it so in essence it's already de-pinned from factory config.

 

[Diboblo]

Well, I'm starting to miss the good o'l days when fuse block was just a fuse block I thought I could just hookup the 2nd pump relay trigger wire to the fuel pump relay, but with the way the pins are setup I'd almost have to fabricate a pin tap for that.

SO, I thought I'll just connect it to the fuel pump fuse, with a fuse tap. Well, that's a special fuse type called "JCASE" and the fuse itself is female pinned. The normal fuses in the trunk distribution box appear to all continue to get power for some time after the car is keyed off (like the radio, etc). I'm gonna have to poke around a bit with a DMM to see if any of them shut down with key off and only power on when car is running.

Man this plug and play deal turned in to a project LOL.

OH, and if I had looked closer I'd have known de-pinning the JMS pigtail wouldn't work. It seems the dual drop in connectors to the FPCM 1 only use 4 pins. A, B, E, and F. That's it so in essence it's already de-pinned from factory config.

There is one ignition switched fuse.

It is on the right hand side and can be moved inline, with the other fuses (always hot), or offset (ignition switched, no delay).

Take a look. There is a photo of it, in my hellcat subwoofer upgrade thread. I'm on the bike, today, so can't shoot a fresh pic.

If you use an add a circuit, it is an atm size fuse.

Sent from my SM-G666 using Tapatalk

 

[Diboblo]

Here are pix of the ignition switched fuse, in the rear power distribution block. This fuse is set to the ignition switched position.

Sent from my SM-G666 using Tapatalk

 

[Speedy!]

Thanks for the pic. Does it keep power when key in run without car running. I bet that's the +12v plug on the passenger side of the trans tunnel.

If it keeps power while in run then I don't think It will work because the pumps will still be running.

 

[Diboblo]

Yes.

It is hot, ACC and Run.

I keep looking.

Sent from my SM-G666 using Tapatalk

 

[BULL]

All of the "add a fuse" hardware I've found is of poor quality.

Is there a brand that is better in quality where the quality can be trusted to not be a failure point?