I have not been able to locate what I think is the proper documentation I think I need to narrow this issue down. So, let me explain what I have and I've managed to find so far.
2007 Ram 1500 Quad Cab 5.7L Gas HEMI 26 Gal tank
It died while driving. It will crank, but not catch and run. Starter fluid will allow it to run for a few seconds. So, I know it is not getting fuel.
I don't have a manual or schematic. Almost everything I find on the Internet, about these symptoms, refers to a fuse panel that does NOT look like what I have. The few I do find do not go into any detail that answer my questions. I have attached pictures of what I have.
First some assumptions. PLEASE, if you know for sure, correct me if I am wrong.
1. The fuel pump is NOT PWM (Pulse Width Modulation) driven. My assumption is based on every fuel pump being offered from the parts houses (AutoZone, NAPA, etc.), for this vehicle, has an over pressure vent (called something else?) to leak unwanted/un-needed fuel pressure back to the tank. It it were PWM, they usually regulate the pressure via that PWM and don't have an over pressure vent. That tells me it is a full on or off of 12 volts to drive the fuel pump.
2. The system does not use a relay for the fuel pump. Besides not being able to find one in the vehicle, the parts houses don't list one either. That usually means the fuse panel circuit boards use solid state switching to run the fuel pump.
So, if I do eventually conclude that the Totally Integrated Power Module (TIPM) is faulty, I COULD, with a simple relay circuit, bypass the TIPM to drive the fuel pump. (I am not saying I will!)
What I do know, so far.
I found a document (attached) that lists the pinout of one of the harness connectors as having the TIPM output pin that drives the fuel pump (Pin 18). I get 12V output on pin 18, briefly when I turn the key to the ON position, and then again full on while it attempts to start in the START position. (BTW, though the document has Dark Blue as the color of the wire hand written on it, my wire is Orange with Red stripe.)
Am I looking at the correct TIPM pin output for the fuel pump power?
Short of me now getting under the vehicle (I am not as flexible as I used to be), I am now looking at getting a new fuel pump. I guess a ground could have come loose, the connector pulled apart, or a squirrel chewed a wire. Still, that is what it is looking like.

Fuse box

Fuse box main board bottom view

Fuse box main board top view

Connector documentation (Gray) Page 1

Connector documentation (Gray) Page 2 My fuel pump output wire was Orange/Red Stripe
Can anybody verify that my diagnosis is in the right direction?

 

i didn't read thru all of your post
wouldnit it be easier to check for power and grd at the fuel pump connector? its located on top of the tank. The pump will cycle on for 2 seconds at key on. if the power and grd is good..replace the pump

 

primem,
I guess if I was a professional mechanic, had thoroughly documented manuals at my fingertips, had octopus arms, and was 20 years old, yes, it would be easier. But, since none of those are true for me, and I could not find the direct path, I followed my nose.

All,
So, I went the long way around. Are my assumptions right or wrong? Is the information I provided totally incorrect? Somebody else may want the answers too!

 

I agree with Prime. Fuel pumps are more common compared to all the other issues you have suggested. Gonna have to get in there and check for power and grounds reaching the fuel pump. Unless you want to work your way from the ecm back towards the tank and pump. Sorry. I cant help with pin outs but seems you have that narrowed down.

 

you have done some good stuff and are on the right track.

my thinking is this. I prefer to check at the component...cause if I get power and grd there...everything before it has to be good. If I check at the tipm first (which isn't wrong) and its ok out of the tipm….I still have to check at the pump.
at the f pump connector there are only 4 wires; 2 for the sending unit which are usually smaller gauge and 2 for the fuel pump which are larger...so I don't even need a wiring diagram.

 

All,
I reviewed the steps for both dropping the tank and lifting the bed, for accessing the fuel pump. I opted to pull the bed. I am glad that I did.
With the bed off, I practiced reaching the connector from under the vehicle. There is no way that connector, or my arm, would have survived without a break. My wife is still laughing from watching me.
The pump has power up to it. I ordered a pump.
Thanks for your help.

 

Good stuff. Hope all goes well with reassembly!

 

Hi Junkyard,
I know this post is several years old but going to ask anyway and hope you are still around.

My truck is doing same thing, Crank no start.
Was wondering, when you turned Ignition to on, were you able to hear the fuel pump relay click inside the fuse box?

Drove truck to store, no issues, came out and be dam if it would start. Kinda odd for pump to die like that but compost happens.
Your post is the only post I found that showed the fuse box that is the same as my truck.

For compost and giggles, I poured a little fuel into the Throttle body port, figured the truck would at least fart when cranking. Nothing, which I thought was odd, I figured it truck would at least fire up for a bit or at least backfire.

 

He hasn't been around since June 2023... but, ya never know.

You should be able to hear the fuel pump prime at initial key on. (if its quiet enough when you try....) If pouring gas down the TB doesn't at least get it to fire once or twice, or even backfire, I would be looking at a spark problem.

 

NotMyGolfBall,

I was never really able to get confirmation from others about whether a fuel pump relay existed somewhere. I did not find one anywhere. Because I did get power at the pump, and the pump acted dead, I replaced the pump. The new pump sprang to life as expected. No clicks. Just the pump whirring.

I guess I could have tested continuity from the pump back to the control board. That would have proved no relay existed in between.Sorry, I did not do that.

Anyway, I attached a couple more pics where the bed was removed. I still say, the bed removal, though not a one man job, was much easier than I expected. It took three people - two to lift the bed and one to find the item to disconnect that you didn't do before lifting. For me it was the ground strap at the front passenger side of the bed. If I had an overhead lift, I guess I could have done it by myself.

It could have been done in a one day. Ordering the pump meant another day. The rain shower added another day.