I did some investigating and turns out my jeep is wired all the way to below the left rear seat for a pump, including a relay and fuse in the power distribution center under the hood. Its labelled (prime pump) on the panel cover, None of this is shown in my factory service manual, but its there!

Hi, Larry. Any chance of a couple photos so others can confirm the connector on their rigs?

Dan

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beers to you

Larry.

I reported the relay and fuse on the power distribution some time ago but didn't trace the wire. If you look on page 8W-10-19 you'll see a dark gray/orange (DG/OR) going to a "fuel pump module" and gives you page numer 8W-30-7 but that page is for gas models But back on 8W10-19 fuel heater and fuel pump along with cabin heater for the viscus heater

I ran into the same thing with fuse F10 in the power distribution box. I do not have the towing package but there's a fuse in position 10 for "Trailer towing" I've traced the pinkish red wire with "VT" (I think it's purple) [RD/VT] into the dashboard area but could not find where it went.

I think there are wires for a lot of things we don't have but finding where they terminate is a puzzle

Larry, is there a red wire with violet stripe under the left rear passanger seat also? Where does the carpet have to be raised to get to these wires??

Thanks
Joe

It would be of great interest if the wire/relay is active when the fuse is installed. Bet they simply used the harness and fuse blocks from the gasser. If it is there, is active, and the control logic is in place, it will certainly simplify the install of a after market pump.

It sure would be fantastic if the gasser in-tank pump would fit our model. With an apparently active circuit there, it might be a very cheap and efficent fix.

Wait....

So our CRD's don't have a pump by the tank just a lift pump at the engine and a hi pressure common rail pump???

This doesn't make sense. When I parked my CRD in the ditch and only had maybe 1/2 gallon of full in the tank it started and quit. If the CRD only had the lift pump at the engine WHY didn't in run fine on the fuel left in the fuel filter and the lines???? Please correct me if I'm wrong here?

When mine rolled over it sucked ALOT of air and there was no fuel left in the system at all.

Once the siphon is lost it needs to be re-primed.

In the power distrubition center under the hood it has fuse cavity f-17 labeled fuel prime pump and there is a relay (#38 ) labelled fuel prime pump. From the relay I traced the load side wire (brown with white tracer) to connector C-100 (behind the left kick panel) , there it changed to dark green with orange tracer. From there it goes to connector C-201 ( a black connector under the dash, just right of the steering column). It then changes to dark blue with orange tracer. Then it runs along the floor under the front left seat to under the left rear seat. If you pull the carpet up under the left rear seat you will find a light grey 10 pin connector. This is where the dark blue wire with orange tracer ends. I connected a voltmeter to this wire and with the key on It has 12 volts for approx. 15 seconds, and 12 volts all the time when running. I hooked it up today, no chance to run a long road test yet.

Hope this helps, let me know if any of your jeeps have this .

Question....does the owners manual identify this fuse? I would check mine but we're on a long road trip in our GC. I sure sounds like Jeep intended for there to be a lift pump. I would bet the gassers are ID'd as a fuel pump not a prime pump.

I looked and found the fuse and relay and does appear to be for a prime pump. When I get the time I will check to see if its activated there. Maybe a lift pump can be mounted under the hood near the filter and be easy to wire there.

most newer fuel injected gas engines have a short "primer" burst from the fuel pump as soon as the key is turned on. The pump then comes on steady after the oil pressure is up to spec. to feed the engine. I'm not sure why they would call it a prime pump instead of a fuel pump though.

I just checked my electronic copy of the manual. The gasser has a 20 fuse for the fuel pump in F24 and a relay in R29. Ths is in the PDC under the hood not the under dash fuse block

This version of the manual show F17 for the diesel as open. Now I need to check that actual fuse block when we get home.

litton

In my 06's PDC there is a fuse in position F17 for "Priming pump" and a relay R38 for fuel priming.

I also do not have the towing package but have a F10 for Trailer Tow.

Pardon my ignorance, but what is a "Prime Pump" for a diesel application? Is it to ease/aide the work of the lift pump? Would the addition of a prime pump allow the addition of filtration before the stock filter assembly?

Thanks in advance for an explanation.

Ignorance Disclaimer: This is my first diesel, but not my last. I'm a total convert.

The owners manual does not i.d. the prime pump fuse or relay. All you need to do is pick-up the carpet under the left rear seat and check for a blue wire with orange tracer.

Great work Larry! I'm checking mine tomorrow .

I'm sure the gasser pump will fit, but it will be high pressure and could blow the seals on the CP3 pump.

Greg

I think the difference is wording only but could be wrong Your question is very relevant as better filteration and eliminating air in the filter seem to require pumping action in or very near the fuel tank

I don't know about the gas liberty but on most other vehicles the in-tank lift pump is very low pressure ( approximately 5lb) the fuel then gos to a high pressure pump under the frame rail (35lb). If the lift pump from the gas model will fit our tank I think that this will be a viable option for us. Also undetectable at the dealer