Chasing ghosts....

[Djouglasth]

2007 1500 5.7 hemi 163k - 30 miles into highway drive today I suddenly lost power and oil pressure according to dash - check gages light came on. Checked all fluids and FULL. No sign of leak or dump of fluids.

On side of highway, replaced battery (bad cell) and had alternator tested (passed 14amps). Replaced oil sending unit/sensor.
Now truck will crank but not turn over and start. Towed home to continue chasing this ghost....
Where to start?

 

[grpht03ram]

What are the check engine codes?

 

[Djouglasth]

No check engine codes.

 

[grpht03ram]

Maybe fuel pump or fuel pump relay?

Do you hear the fuel pump whine when you turn the key? Turn the key just enough to light up the dash, not to crank/start, and listen for the pump

 

[Djouglasth]

Thanks for confirming my suspicion grphat03 - That’s next step - this year/make doesn’t have relay so can’t jumper it or replace fuse. So, going to check wire harness connection on frame rail driver side (clean and check for power) - if power at harness connection - then I’m going to assume pump is bad (if no whine as well).
will keep situation updated.

 

[Luke Chapman]

This sounds like a pretty similar problem that I’m currently facing. When you stop at a red light does the oil pressure drop and the check gauges light come on?

 

[Djouglasth]

Luke - mine happened all at once. Instant loss of power on highway and still not running....chasing one symptom after another.
From other forums I’ve read - I would suggest you start with the our pressure sensor. It’s an easy fix and could solve your problem. If you try that and still nothing...follow along as I journey down the rabbit hole

 

[Djouglasth]

UPDATE - tested electrical from battery at harness connector driver side on frame behind wheel well - 10.6V on startup (brand new battery) and still no start. Cranks but no start).

 

[Djouglasth]

UPDATE - wiring harness connections cleaned and tested - power from battery good to connector. Fuel pump made no whine when tested. next step will be fuel pump replacement.

 

[MoPowered]

Crank sensor? Had it happen on my 99’ 5.9 just throwing it out there.

 

[Redtruck-VA]

Fuel pump should run for a few seconds when ignition key is first turned on. If no engine rotation is sensed then ASD relay cuts off removing power from fuel pump, coils and injectors..

 

[Djouglasth]

Redtruck - copy all that. Problem is - I’m not getting initial fuel pump activation prior to crank.

 

[Redtruck-VA]

Redtruck - copy all that. Problem is - I’m not getting initial fuel pump activation prior to crank.

Ok, I'd measure voltage at a coil when the ignition is first turned on. Or ASD relay..

 

[grpht03ram]

I attached the fuel delivery diagnostics section from the 2006 service manual. Hope it helps.

Its a pdf file. 2 pages.

I don't have the 07 manual

 

[Djouglasth]

Grpht03 - this info is awesome - unfortunately does not apply to 07. For some reason the 07 doesn’t have a fuel pump relay if I’m understanding this document correctly.
Any chance you can send me same info from 07 manual? Or point me in direction to track down on my own? Thanks again!!!

 

[LoneWolf3574]

Try a search for "2007 Dodge Ram Factory Service Manual" or "2007 Dodge Ram FSM". However, to be honest, the only thing I could find was 2002-2006, 2008; a 2007 FSM seems to be a unicorn even after 13+ years. Scrolling through the posts, it would seem that even HemiLonestar couldn't find one. You might try using a combination of the 2006 and 2008 FSM, I would think that if they changed things in 2007 it may have carried over to 2008.

This guy condensed all the links posted for the 2001-2008 Parts and Service manuals made available to this forum. I've included his post for you, if you would like to browse it all, the link to the first post of the discussion is in my signature.
3rd gen parts manuals and 2003 2004 service manuals

 

[grpht03ram]

I hope you don't need a whole new/rebuilt TIPM

 

[Djouglasth]

LoneWolf -
I tracked down a 2008 FSM (all 10,000+ pages) and am still digging through to find specs on my issue -
does replacing fuel pump seem like right path (thats where I'm currently headed) considering I checked electrical from battery to module and seems a little low but should be enough to activate fuel pump.

Try a search for "2007 Dodge Ram Factory Service Manual" or "2007 Dodge Ram FSM". However, to be honest, the only thing I could find was 2002-2006, 2008; a 2007 FSM seems to be a unicorn even after 13+ years. Scrolling through the posts, it would seem that even HemiLonestar couldn't find one. You might try using a combination of the 2006 and 2008 FSM, I would think that if they changed things in 2007 it may have carried over to 2008.

This guy condensed all the links posted for the 2001-2008 Parts and Service manuals made available to this forum. I've included his post for you, if you would like to browse it all, the link to the first post of the discussion is in my signature.
3rd gen parts manuals and 2003 2004 service manuals

 

[grpht03ram]

Before you go buy a new fuel pump, it could be the relay.

Your fuel pump relay is integrated into your TIPM. It's not easily replaceable like a normal relay; its soldered in place. Horrible design.

It could indeed just be the relay. However it can only be replaced by either replacing the whole TIPM with a new or rebuilt, or taking apart and soldering in a new relay.

There must be a way you can test the fuel pump either by directly putting 12V or testing with a multimeter. It's so hard to access though. I hope someone here can you help you out more.

If it's not the relay, then yes fuel pump most likely.

You can use control+f to search PDF documents. maybe search "no start" or "fuel delivery"

 

[Djouglasth]

Grpht03 - I agree you on with the TIPM issue and lack of relay (for some dumb reason they stopped fused relays on 07 models). REALLY hoping its not TIPM. Don't think Im ready to re-solder relays - might be my tap-out limit.

As for testing power to pump - I did put multimeter (DC setting) on C10 harness at fuel pump locations/wire (along frame rail driver side right behind front wheel) and got 10.6V on new battery on crank. So i know I have power going TO pump but pump never activated. So its either writing from C10 to pump or pump itself - hence the ordering of new pump. To replace pump Ive decided to lift bed rather than drop tank (tank is FULL 25 gallons). So for now just trying to gather info, learn as much as possible and prep for pump delivery. 162K miles so new pump can't hurt if its not the issue. Should be noted that NO new or stored engine codes and only get red lightning bolt on crank (still no start). Also thinking it wouldn't be horrible time to do spark plugs but thats just guess-work waiting for pump to arrive....thanks again.