07 hemi ram mega cab is down

I have an 07 ram mega cab with a hemi and auto trans. It has about 70,000 miles on it. Been a great truck but I drove it home and turned it off and it hasn't started since. I can put the key in and everything works. Lights come on. Gauges move normally. When I turn the key to start, the dash lights go off and it makes a click under the dash. Release key and lights come on gauges move but will not crank and I'm not hearing the fuel pump. I found the clicking under the dash to be the box on the shifter cable. I can get it out of park with the key on and tried in neutral and nothing. This far I have checked the fuses and all are good. I charged the battery and it tests good. The only thing that has changed is the weather. Parked it and the outside temp was 27 since then it has been -0.... Could the cold temp have it acting up? Last winter and a few times this winter when I would start it there would be a loud noise under the hood. I thought it was a cold power steering pump. Could it be the starter hanging? Could it be bad? I'm looking for possibile problems. I put the scanner on it and it says no codes. Tried both keys.

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If it don't feel rite.... It isnt!

Use a volt meter to verify that the battery is not dead. You have to have the meter across the battery while attempting to start the truck.

That sounds like a classic dirty battery terminal - all seems ok until crank whereupon (click &) all goes dark until released whereupon electrics MAY return.

Check for looseness else loosen the battery terminals and wiggle & re-tighten to get out of trouble, otherwise remove & clean terminals & replace. (NB - for typical -ve GND vehicles, the -ve battery terminal should always be disconnected when working on the +ve - ie, -ve off first and on last.)

It's possibly the same problem elsewhere - ie, a dirty or loose connection at the engine ground end, and maybe chassis end.


It could also be a weak or damaged battery, but it's rare to have lights etc at full brightness with full recovery.
... Tho I've just realised I interpreted "lights" as meaning main beams...
If lights mean dash lights only, then turning on headlights is a good test of battery strength, but also the aforementioned bad connections.

Well..... I put it in the shop and got it warm, replaced battery. Cleaned all connections and still no crank. I used a test light to check the wires on the starter and the battery cable on starter has power and much to my surprise the small yellow wire has power too. Even with the key off. My next step is find out how much power each one has. Can anyone tell me if this is normal? Or could my starter be shorted out and back feeding the yellow wire. Both wires go to the starter solenoid. Shouldn't the small yellow wire energize to make the starter engage?

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If it don't feel rite.... It isnt!

Back in October my starter went out. Same symptoms as your truck. 92 Chevy K1500, 86000 miles, No indications of pending doom. Just stopped working. No clicking at the solenoid, all lights and gauges work as normal, just no start. Dead starter.

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The starter solenoid wire should not normally have +12V on it. It may be a high resistance "leak" from its heavy +12V contacts (a test light should determine that) else indicative of a solenoid fault - whether frozen or seized in the on position, or insulation breakdown etc.
It could be that the starter gear is stuck in the ring gear hence keeping the heavy solenoid contacts closed (feeding heavy +12V into the solenoid and its (small) wire), but that means constant "cranking" and hence a hot or smoking starter and a heavily flattening battery.


Normally shorting the starter solenoid terminal to the heavy +12V with a screwdriver or spanner etc (but NOT any other grounded engine/gearbox body parts!) should pull the solenoid in which (1) closes the heavy +12V contacts to the startermotor & (2) pushes out the gear into the flywheel ring gear.
It will give a reasonably hefty spark because of the relatively high-current solenoid (typically 40A when initiated) but that's nothing to fear. (Unlike shorting to GND where the melting spanner or exploding battery is worthy of fear!)

If that manual short (contact bridging) does not crank, then unless it's a bad battery, it's a starter motor fault (shorted or open windings, worn brushes, seized mechanicals, etc).

Well got under it and shorted it out with key on. Cranks perfect but no start. Match anyone ?

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If it don't feel rite.... It isnt!

So it's not a battery capacity issue since it can crank the starter.
The starter is ok - it cranks.

The IG key won't crank the starter - hence keyswitch or starter relay problem.

The engine won't start despite cranking with IGN on - faulty fuel pump relay or pump? Else fuel (no fuel, blocked filters etc). Else IGN (spark etc). Or controllers (ECU) & sensors, injectors etc.
You now start the process of elimination.

BTW - ROTATE your (same sized) fuses, and disconnect & reconnect all involved connectors (to relays, wiring harnesses, sensors etc).

Well... I have replaced all fuses unplugged and re plugged sensors. I can't hear the fuel pump so I relieved pressure at the engine then turned on key and fuel pump is working. I started testing wires at the ignition switch harness. I found that when I turn on the key everything works, dash lights come on, gauges come up. But when testing the pink/white + ignition wire with key on I have zero volts. It remains dead despite the dash powering up. I put a pos wire from the battery to the pink/ white ignition wire with key off and it powers up the dash as if turning key on. With this jumper wire connected the engine will start with the key and do exactly what it's supposed to do. While engine is running I can unhook the jumper wire and it remains running. I'm not sure where to look for a problem with this discovery.

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If it don't feel rite.... It isnt!

I don't have any wiring diagrams etc, but from other sources it seems that pink/white is IGN +12V.
Hence I'd suggest checking the IGN relay (if fitted) - maybe swap with another similar relay (eg, ACC).

And did you rotate else replace flinks (fusible links) (if fited)?

Classic symptoms of a dead starter solenoid or switch. At this point we've proven that there is the ability to move enough current through the cables from BATT to starter, so we know the battery is good and the primary cables are good. Jumping off the starter solenoid terminals shows us the output to the starter is likewise G2G.

This leaves us with the high likelihood of a bad starter solenoid (which may be part of the starter, I'm a Chevy guy so don't know how Dodge does it), or a bad trigger TO said solenoid (which would point at the ignition solenoid.

Next trick is to take a wire from the battery (look on your wiring diagram to see if it's negative or positive trigger that actuates the starter solenoid) directly to the starter solenoid trigger.

-Break- So I got curious, and figured this was close to what you are working on, right?
https://www.oreillyauto.com/site/c/search.oap?keyword=starter&year=2007&make=Dodge&model=Ram+2500&vi=1434834

OK if so (and likely even if not, manufacturers tend to follow similar build methods across a given line), then you have an integrated starter solenoid assembly (part of the starter motor itself).

If so, check this video and follow his advice:
https://www.youtube.com/watch?v=UnmnWuuLfzE . He picks up where I left off before the "break" above, at about 04:30. You don't need a fancy switch to test the trigger side of things- just a piece of wire will work fine- 10GA or better, and do be careful!

I really think you're looking at a bum starter.

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"Always listen to experts. They'll tell you what can't be done, and why. Then do it. - Robert A. Heinlein"

I just noticed....

houpy] wrote:

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can't hear the fuel pump so I relieved pressure at the engine then turned on key and fuel pump is working.

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I presume you mean you relieved the fuel pressure after the pump(?)!

For a sec I thought you meant oil pressure was controlling the fuel pump or relay (which IMO tho acceptable in some competitive circles, it should not be preferred or allowed) and that should require pressure to enable the fuel pump, not a pressure release.

Phew!