well here we go again. thought my lp was out so i replaced it with a FASS. the problem seems to be with the ecm not sending power to the relay. has anybody had a problem like this before? is there a way to check the wire for a split? can i install a toggle switch and bypass the ecm control altogether? just spent $475 for the pump cannot afford to replace the ecm also.

 

check your fuses first then try a test light to the fass if all else fails run a toggle switch to the pump

 

if i toggle it will it throw the ecm into loops? has anybody ever dons this before? i have checked all the fuses that i can find. i can hook a hot wire up to where the stock liunes feed and my pump runs thats why i thought about the toggle but was afraid something else might not work right without going thru the ecm.

 

Running toggle for pump will be fine, if that is what you want to do

 

not sure what else i can do other than replace the ecm. in order to get it tested i'm going to have to get it into the shop.

 

Make sure your harness that comes with the FASS is trasmitting power. I know of quite a few that came with bad connections. Check for continuity first.

 

Another thought is check your power wire that you are using to the FASS pump. Disconnect it from the FASS pump and user a voltmeter and see if you have at least 12 VDC with no load. You may need to use a relay with the wire that went to your old lift pump as a trigger wire and the 12 VDC from another power source. It is possible that the additional current draw of the FASS pump may be signaling the ECM you have a overload so it shuts down the voltage to that wire.

Good luck,...........dogger

 

I am curious as well, did your truck just up and die one day? Or, had the LP been going out for awhile? Or, was the truck running BEFORE you put the FASS on, and now it does not?

 

ok here we go i will try to answer everybodys questions as i have not been on here today. 1st when i hit the FASS wire that trigers the relay with a supply from the battery the pump runs, so the FASS pump, wiring, and instalation are all good. 2nd the truck was running untill i hit the brakes and didn't take the truck out of gear(i was yelling at my kids) after it stalled out i restarted it and it spittered and sputtered home at 20 mph. After i got home i turned the switch on but didn't hear the pump run. with all the lift problems i figured the pump went out so i got the FASS system. after install i still was not getting power to the pump from the ECM. I contacted enterprise engine performance where i bought the pump from and they told me they have experenced simular problems before and just installed a toggle switch or wired off the ignition side of the key switch (to prevent pump from running all the time by forgeting to turn it off)
I am going out right now to wire the switch up and pray that everything else is good. I will post again tonight to let everybody know how is goes.

 

ok heres the update. i just finished installing a toggle switch that i powered off the hot side of the key switch. the toggle is basicly just a safety shut off or in case i need the key on but not the pump. i found a empty slot in the power distrubition box that is only hot when the key is turned on. i ran a wire from that to the toggle switch that runs back to the relay for the pump. i got it all wired up and the truck started. i took it for a prelimanary test run down the street and back, so far everything seems fine. i am going for a longer test run now.