Well I talked with Michael about my install and he was not sure exactly how the wiring is. Been over six months and a lot of installs. He has another truck like mine back in for other work that he said should be identical to mine and will try to check and see exactly. I know he used the factory wiring to the LP for at least for some controls.

Mine is too quiet, Michael modified the mounting brackets and I think used bushings to minimize the pump noise/vibration. Mounted higher than normal and with the wheel well liners, just cant hear it run.

I thought and still think the CP3 should be able to pull enough fuel through the FASS to idle for a minute or two.

Well not sure why, but my cool down timer function works every time, with no indication of any fuel delivery issue. Probably be this weekend before I can get under the truck with meter and verify if the FASS is running or if CP3 is pulling fuel on it own in cool down mode,

 

The 03-04.5 uses a harness that plugs into the stock lift pump connector. On that same harness but upstream from the relay is a pig tail with wires that go to the battery using ring lugs they provide that aslo contains an inline fuse. Basically what you have then is a 12 volt fused source from the battery that is switchable with a relay that is run from the stock lift pump harness. That is how mine is wired up and I didn't change anything from the wiring instructions and harness that FASS sends with their unit.

At noon I will measure the voltage coming out of the stock lift pump harness and post back the results.

 

Is the factory harness the weak spot in using the stock pump power supply at the tank or the relay circuit in the fuse panel? Could they make a jumper plug that went between the factory plug and socket on the fuel tank that would still allow power to the sending unit (and back) but divert 12v power to the FASS pump instead of the factory pump? Or is this the cannot work scenario ABC is referring to.

John,

I should be back down in Houston by mid-next week, if I don't have a solution by then I will have to get with you and see what Mike did to your rig up. Other than the loss of my cool down feature, everything seems to be working pretty good.

 

[[COLOR=Cyan]QUOTE=staarma]The 03-04.5 uses a harness that plugs into the stock lift pump connector. On that same harness but upstream from the relay is a pig tail with wires that go to the battery using ring lugs they provide that aslo contains an inline fuse. Basically what you have then is a 12 volt fused source from the battery that is switchable with a relay that is run from the stock lift pump harness. That is how mine is wired up and I didn't change anything from the wiring instructions and harness that FASS sends with their unit.

At noon I will measure the voltage coming out of the stock lift pump harness and post back the results.[/QUOTE]


Staarma, you may be on to something with that type of rig up, just need to find out what has possibly changed with the 05's. I will be very interested to see what TST comes back with for a solution.

Anyone know the amp draw difference between the FASS 95 and 150?

 

Funny you should mention amp draw. I just measured the voltage output for the stock lift pump. It is 11.68 volts with key on engine off and 13.8 with engine on. I did not measure the draw though. I was thinking that FASS new that the current draw for their pump was too much for the stock connector so they went with a pig tail to the battery and used the stock connector to run the relay. I was thinking they did that because the voltage from the ECU must have been only 0-5 volts. I was wrong, it seems to be getting alternating power of almost 14 volts but the current might not meet their specs. The 05 though is different because they use the stock harness to run the FASS on the 05-06 trucks. Someone else said the in tank stock pump runs on a 30 amp circuit compared to the 20 amp on the filter mounted lift pumps. Makes sense.

Cquestad, I would still run a direct harness to your battery with heavier gauge wire and use the stock connector to run a relay though. The heavier gauge wire shouldn't loose much current like the stock 16 gauge wire does. This has got to be the only reason FASS went with the heavier wire and direct battery source. I stand corrected on the stock lift pump voltage supply. Sorry.

I hope I'm helping instead of confusing the matter even more. If I'm not helping then someone tell me to shut up.

 

The 05 though is different because they use the stock harness to run the FASS on the 05-06 trucks. Someone else said the in tank stock pump runs on a 30 amp circuit compared to the 20 amp on the filter mounted lift pumps. Makes sense.


The 05 FASS does not use the factory harness for ANYTHING. It is grounded to the battery and positive to the hot side of the cigar fuse with a fuse tap. Cheap and nasty, no bells or whistles, just pumps when the key is on. There is more technology in an anvil than this rig up supplied by them.

 

I just realized what they were doing. I was wrong. It wouldn't take much effort to run to the battery with the same fuse tap running a relay but the problem is the keyed voltage would be hard to get away from. I think the only way to go would be for TST to provide a voltage output to run the relay so as long as their module is running it would run the pump. Would be a circuit board turn on their part with another channel loaded on the board using a 0-5 volt analog output. No big deal at all.

 

BD,

That is how mine is connected also. I checked and yes it is per FASS instructions that came with the unit for my 04.5 with external LP. It is a very staight forward hookup.

I know that Michael installed one on an 05, maybe I'll get down to his place this weekend and see what he did on the 05.

 

I've got the O5 on my truck because it came with the pipe in tank pickup which I wanted....all I need is the 03 harness. I'm getting the TSTupgraded soon and I'll get the FASS upgraded at the same time. ks