[ZLRob]

Originally Posted by KingLT1

Supposed too...green light on all the time is going to drain the battery over time.

I know mine certainly stayed on all the time. I just let it be and chalked it up to general parasitic draw that the car naturally has but I was never entirely good with knowing the light was always on.

[RobZL1]

Originally Posted by ZLRob

If you talk to Katech directly about the JMS they will tell you firsthand that their fuel pump setup has never been tested with the JMS and they don't recommend running it. Having personally tried it out that way prior to knowing that from Katech I saw how and why it would cause issues with the secondary.

Long story short, it's not worth it, and it's easier to fine tune the FPDCM from HPT if you are really looking for that much level of control out of the primary and by extension the secondary pump.

Katech has issues with their early dual fuel pump setups, that of which I own one and am currently having issues with myself. I love their products but the fact that it is so difficult to install and remove in and out of the tank A. and B. Traditionally requires tank removal to access the fuel pump (a non existent issue for me now), has me really irate about it all.

Got it. I thought the 2nd Katech pump was entirely controlled by a vaporworx controller and not tied to the factory control at all. Basically an aux pump setup, but it's just in the tank. I didn't think the two interacted at all, so that's my bad.

[swisstyphoon]

Just went through the same thing recently. I removed my JMS voltage booster when I installed the DSX dual in-tank setup.

The newer JMS units (like the one I had) don’t drain the battery, I measured the draw myself, and it shuts off completely when the car is off, so no parasitic loss.

Ted Jannetty told me I could keep the JMS if you tie it into the second FSCM, or just remove it, either way works depending on how much fuel your setup needs. But then I realized the JMS doesn’t have enough amp output to support both pumps anyway. You’d need the stronger dual-output version for that.

And yes, connecting the red and white wires together will work fine.

[ZLRob]

Originally Posted by RobZL1

Got it. I thought the 2nd Katech pump was entirely controlled by a vaporworx controller and not tied to the factory control at all. Basically an aux pump setup, but it's just in the tank. I didn't think the two interacted at all, so that's my bad.

Yeah it's basically an aux pump without the need to modify the tank for aux pump installation. I never thought of it that way but that's exactly what it is. Lol. Unfortunately the way the OEM setup is, it forces you to interact with it if you want to control a secondary pump, and so with that comes all the headache of integration, proper voltage controls, nuisance code deletion, etc. in order for it all to work seamlessly.

Outside of that, the other solution is full FPDCM deletion in order to run a dual or triple pump setup if you want to go with a return style system, but that introduces a different level of complication that not even I want to start thinking about right now, even though I have a level of knowledge of what would be required to make it possible electronically.

[KingLT1]

Originally Posted by swisstyphoon

Just went through the same thing recently. I removed my JMS voltage booster when I installed the DSX dual in-tank setup.

The newer JMS units (like the one I had) don’t drain the battery, I measured the draw myself, and it shuts off completely when the car is off, so no parasitic loss.

Ted Jannetty told me I could keep the JMS if you tie it into the second FSCM, or just remove it, either way works depending on how much fuel your setup needs. But then I realized the JMS doesn’t have enough amp output to support both pumps anyway. You’d need the stronger dual-output version for that.

And yes, connecting the red and white wires together will work fine.

If the green LED stays on its drawing power. Might not be much but it's something. I will have to check mine again, but I swore the green light went off after so long.

[2023_ZL1-AUTO]

Update: Dug into the install of the JMS this evening and remove it. The JMS device in the trunk was still spliced in to the red/purple at the FSCM connector above the rear axle. So, it was picking up voltage from there causing the JMS Green LED and the device to always be on. I read a post that said 2010 and newer GM's always keep power to that driver/module. But, while removing the JMS kit and I got to the gas peddle connection. I noticed it was hooked back to the stock connector and not the Y-connector the JMS came with. So, Katech unhooked the Y splitter, thus, deactivating the JMS device and preventing the system from kicking in extra voltage. I looked back at emails between Mike and me, and Mike mentioned they "de-activated" the JMS device. But, there would be extra time to remove the JMS completely from the car. I see an email where I told Mike, I'd remove the JMS once I got it back home. So, I guess it was all OK after all, just still installed but not working. I did remove it, and connected the JMS RED and WHITE wires in the trunk and all is good.

[KingLT1]

So I was incorrect. The JMS green light stays on. Mine as well. So anybody running one is dealing with a constant draw from it. Might not be much but it's something. Seems dumb to me...the light should time out with the system.