Electrical issues

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PapaGoose

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So I've finally got the truck running. Did a full rebuild on the engine.
Went with a slightly aggressive Camshaft, new heads all the way around, new rocker shafts/arms, hellcat lifters, 180° thermostat, 3.7l electric radiator fan, mechanical fan delete, replaced all bearings, rings, head bolts, cam bolt, hell cat oil pump, etc etc..

Had a little trouble starting the truck the first few times as the battery had been placed on the concrete shop floor for about a month (yes yes...I know I'm an idiot and didn't pay attention lol)
So, jumped it off, truck started pretty much immediately the first three times on the same day.
Over the course of the next week as I am getting the break in miles, I've been having trouble with the truck not starting/battery not charging and starter acting like the solenoid is stuck, single click then nothing.
So, I do some alternator testing, it is showing my battery is good and is staying above 9v when/if it cranks, it will hold a charge at 12.5v over night so I don't have a drain.
But, the alternator is not charging the battery, voltage stays pretty much the same even when truck is running, around .1-.2v difference.

Took the positive lead off the battery while the truck was running and it died immediately (which I have now learned can damage modules) but shows that the alternator is not charging, so I bought and replaced the alternator.

Still having the starter issue where it clicks once and then nothing, I swapped the starter relay with a different one and it started right up, I took the 2 prong plug off of the alternator (pcm/voltage regulator leads) and the truck started idling a little better and there was a whine inside the alternator that went away? As well as the same issue of the battery is not charging with the alternator...

Now after switching the same relays back and forth the starter is still single clicking and not cranking/starting at all.

Lights on dash stay on, so I know it isn't the battery, plus I've tried jumping it, kept a meter on the battery to test voltage drop....nothing indicates battery at all.


During one of the single "clicks" I saw sparks shoot out from roughly where the starter is, I was on top of the engine bay testing the battery voltage at that time. Got under the vehicle and traced every wire I could down there, no burning smell, no burr where metal had fused to the wire at a short, no burned casing or melted plastic, the battery lead and ignition lead on the starter are nowhere near other metal and again. No burned areas or loose anything.
There is a single "metal" plate at the back of the AC compressor that is not bolted down as when I got the truck the rear bolt was missing from the compressor and the hole appeared to be rusted as well as the threads on the block, the plate itself does not look like a ground strap either, it looks more like a mounting tab to keep the harness from moving.

From you guys that know a lot more than me and have had a lot more experience than me.

Is that metal tab at the back of the AC compressor a ground?
Could the sparks thrown from the starter area potentially messed up the PCM? Or the pulling the positive lead off the battery?
I don't want to keep throwing parts here and a PCM is 300$+ and still could leave me with a potentially bad starter or bad ignition switch (I am about to go test starter by jumping the ignition wire to 12v battery see if the starter engages)

If the starter is bad could it prevent the battery from charging or am I SOL and have to spend 200$ on a starter as well as replace the pcm?
 

EdGs

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To me, 9v when trying to crank is pretty low.

Has the battery been load tested?

You said your alternator output does not change and it dies if you unhook the battery when running. Sure seems like alternator circuit to me.

However, these Rams don't work the same way as the conventional style circuits I am used to. I believe the output to the battery gets varied by the pcm.

Hang in there.
 

CamperMike

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If you jump the truck, does it start right now? If you get it running, what is the voltage with the replaced alternator?
 

turkeybird56

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To me, 9v when trying to crank is pretty low.

Has the battery been load tested?

You said your alternator output does not change and it dies if you unhook the battery when running. Sure seems like alternator circuit to me.

However, these Rams don't work the same way as the conventional style circuits I am used to. I believe the output to the battery gets varied by the pcm.

Hang in there.
Well, on MY 19, yup PCM controls. Not know if 2012 different. OP, do not do the old GM trick of pull a cable to see if still runs, bad JU JU there. 9V cranking, way too low, get battery tested, prob new battery and check again,. IMHO. Heck, even my Lawn Tractor maintains over 11 volts when cranking, more like 12.2, so 9 volts, way too low. Battery not doing well under load.
 

EdGs

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Plus, you mention seeing sparks. THAT needs to be looked over further.

The only times I ever see sparking would be from a loose connection, or something pinched and shorted. Very easy for either one to happen, been there and done that, as much as I hate to admit it.
 
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PapaGoose

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Hey guys, sorry I wasn't clear.

The battery DOES NOT drop below 11v when cranking so battery is fine.

I got the truck cranked and running right now, voltage on battery at first few seconds showed 14v but then quickly started dropping back to 12.5v
Now when I push down on the alternator plug (brown and red wire, voltage regulator) it starts very slowly charging while the alternator is whining, bur if I release pressure from the plug it stops charging. This plug doesn't seem to be grabbing onto the post like it should.

May have to replace it or zip tie it down?
 

crazykid1994

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The pcm needs to see battery to tell the alternator to run. If the starter is dragging after releasing the key could be a potential issue. I would load check the starter. Also I agree. Try a new battery anyways.
 

crazykid1994

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Hey guys, sorry I wasn't clear.

The battery DOES NOT drop below 11v when cranking so battery is fine.

I got the truck cranked and running right now, voltage on battery at first few seconds showed 14v but then quickly started dropping back to 12.5v
Now when I push down on the alternator plug (brown and red wire, voltage regulator) it starts very slowly charging while the alternator is whining, bur if I release pressure from the plug it stops charging. This plug doesn't seem to be grabbing onto the post like it should.

May have to replace it or zip tie it down?
You could remove the alternator and take it to an auto parts store for testing. The whining could be a failed alternator
 
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PapaGoose

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Plus, you mention seeing sparks. THAT needs to be looked over further.

The only times I ever see sparking would be from a loose connection, or something pinched and shorted. Very easy for either one to happen, been there and done that, as much as I hate to admit it.
The sparks came from a loose ground that I finally found. I swear I checked that Blick ground the other day but I guess it got hung up on something and didn't wiggle. Oh well it is tight now and truck started right up.

So my main and only issue right now is the charging system light is on, on the dash and the alt seems to be fine as I was charging at the beginning but the 14v dropped until I pushed down on the alternator plug
 

EdGs

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Hey guys, sorry I wasn't clear.

The battery DOES NOT drop below 11v when cranking so battery is fine.

I got the truck cranked and running right now, voltage on battery at first few seconds showed 14v but then quickly started dropping back to 12.5v
Now when I push down on the alternator plug (brown and red wire, voltage regulator) it starts very slowly charging while the alternator is whining, bur if I release pressure from the plug it stops charging. This plug doesn't seem to be grabbing onto the post like it should.

May have to replace it or zip tie it down?
Definately replace that, you shouldn't have to hold it. Go to a u-pull, and get one from a junker, just make sure it's in decent shape.
 
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PapaGoose

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Definately replace that, you shouldn't have to hold it. Go to a u-pull, and get one from a junker, just make sure it's in decent shape.
See that's what I was thinking...

When I first got the truck to crank just now after fixing the ground issue, the battery showed 14.09v so alt was charging, but as I was holding meter to it, it started to drop ending around 12.5v
I reached over and wiggled the plug/pushed down on it and it started climbing back up, but very very slowly as in going between 12.56v to 12.57v then back down then back up to 12.58v etc etc.
But now when I hold/move the plug (I messed around with the latch on the plug to make it click into place which it finally did) it doesn't change the voltage and after having it completely unplugged and cranking up the truck battery voltage was sitting at 11.93v, same thing..wiggle/push on the plug and it slowly went up to 12.3v but no further, though was not dropping either.

I'm wondering if the PCM/voltage reg is either not getting a good connection via the plug, or if it's just not charging it up to the 14v like I'm used to seeing?

I've tried the jumper from battery positive to the brown (pcm wire) on that plug with 0 change to voltage on battery however again...the battery showed the 14v when the truck first cranked up (has not gone back up to that 14v a single time since even when starting the truck again)
But the battery still stays well above 10-11v on start. The battery was load tested at the inspection station (guys there are very good and I trust them and their equipment) showing a stable 12v at 800-1000cca but did not jump up with the alternator which led me to replace the alternator first
 

heliodoc

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As far as the plug to the alternator is concerned try this. Find the male pins. With some small needle nose or hemostat pliers twist the pin about 15 degrees. Sometimes aftermarket pin sizes can be different sized or even worn.
 

REDNECK28871

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Placing a battery on a concrete floor does not draw power out of it. That was only true about a hundred years ago ehrn they had the old tar style cases.
 

Dusty

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Placing a battery on a concrete floor does not draw power out of it. That was only true about a hundred years ago ehrn they had the old tar style cases.
Redneck is correct. However, there are other effects potentially more detrimental. Battery info:


Regards,
Dusty
2019 Ram 1500 Billet Silver Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 3 June 2018. Now at 79001 miles
 

TomB 1269

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These trucks utilize the PCM to regulate the alternator output. As someone said earlier pulling wires while running can cause bad JU JU. I think it bit you. If all else is good you most likely fried the PCM regulator, and if so the battery light will come on even if the alternator is putting out voltage/current.

I have seen that before when my brother welded on his jeep and did not disconnect / isolate his PCM. He ended up having to put in a switch and large capacitor to discharge to... It was purely an off-road jeep at the time.
 
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