Bottom Line Up Front: Trying to hunt down the cause for my truck's misbehavior. Starting the truck brings the dreaded starter solenoid. Not convinced it's the starter, battery, ignition switch, or something more electrically elusive.

Earlier last week, the first freezing day of the season came upon us, and lo and behold, the truck wouldn't start. No indications of any charging problems or battery problems leading up to this. I am, however, chasing an elusive coolant leak (more on why I mention that in a minute).

On that Tuesday, the most obvious symptom is that I could turn the key to start and I can hear the starter solenoid chatter. Checked the battery, which read 12.4 volts. After a couple of attempts at starting, I could tell I was draining the battery. That said, in that process, I noted that when the key was in the Run position, it seemed like there was just enough play in the key position such that I would get abnormal instrument panel indications - indicator lights and gages behaving erratically, in particular. This was also intermittent; I wasn't able to replicate this every time.

Not having much time to mess any more with it during the week, I started troubleshooting it again yesterday. Just for giggles and grins, I put attempted to start, and got the same indications UNTIL, about 3 seconds in, just as I released the key, it sounded like the truck turned over very briefly. Surprised by this, I attempted to start again and it the engine fired immediately. I let the engine run for about 15 minutes, then stopped the engine, and immediately restarted. I let it run for another minute, and then stopped the engine again. Ten minutes later, I tried again, and was unable to start the engine - same symptoms as before.

Thinking it was a possibly a bad starter solenoid, I obtained a new starter and installed it this morning. No change; if anything, the truck started behaving like it had low voltage - relays start chattering, dim lights, etc. I took the battery to get it tested afterwards, and after spending 90 minutes on the wham-o-dyne testing machine, the battery came back in spec (despite its age - January 2016).

Cleaned some terminals, reinstalled the battery, and no change.

I've checked all fuses in the distribution box under the hood, with good visual and electrical continuity checks.

So, thinking out loud, here's where I think, moving forward to isolate the problem:
- Check/replace the starter solenoid relay.
- Check/replace ignition switch.

If those don't do the trick, them I think I'm into:
- Checking ground connections (not sure where to start there)
- Battery replacement
- Checking compression (or, really, checking to see coolant where it shouldn't be - see thread here.)

I'm leaning towards an electrical issue, given how I was able to suddenly start, the unable to start the engine on Saturday. That said, I'd appreciate any sage wisdom of the collective that I should also be considering and would be truly grateful.

 

Step A: Properly load test the battery with a carbon pile or similar. I have no idea what a wham-o-dyne is but load testing should not take 90 minutes. Or maybe you can borrow a battery from a buddy to test with.
Step B: Check all battery/alternator wiring and grounds.
Which lights get dim ? Things like dome lights or exterior lights don't go through the ignition switch so if they get dim I'd rule out the ignition switch for now.

 

The usual live spam of a battery is 5 years. I have had ones fail sooner. You didn't mention anything about if it's charging. A weak battery can still show 12 volts until you put a load on it. I too never heard of a "wham-o-dyne testing machine". take it to an autozone or anyone that will test it for free. And make sure ti's charged before you do!

 

Lol...I didn't even realize I had typed out wham-o-dyne...that's what I get for typing what I was thinking.

To be more specific re: battery testing, I took it to my local Advance Auto Parts, where they first used their mobile tester, noted that the voltage was 12.2V (after I had attempted to crank the truck several times unsuccessfully) and the CCA came back as 612 CCA (rated for 650). The agreed to place my battery on their machine in the back part of the store - not sure if it's a battery charger/conditioner/tester/whatever; after 90 minutes they pulled the battery off the machine, ran it through their mobile tester again, and noted 12.7V and 610 CCA.

To the question, "which lights get dim" - everything goes very dim - dome light, instrument panel (accompanied by erratic reading). Have not tried starting with the headlights on, but would assume the same behavior.

To the question re: charging, up this point, the voltmeter on the instrument panel consistently read 14V while the truck was running, with most transits between 45-60 minutes twice a day. No charging system light ever illuminated.

To the point: "A weak battery can still show 12 volts until you put a load on it." - agreed. My assumption that this was part of the procedure performed at Advance Auto Parts may be in error.

Thanks for the comments so far - much appreciated.

 

Another thing you can do is connect a voltmeter directly to the battery and see how much the voltage drops when trying to crank.

I'm still leaning towards an issue with the battery wiring/grounds. High resistance causes little voltage drop with light load (interior lights, PCM) but a lot of drop when the bad connection is carrying high current (starting). You can check the ground connection by using a jumper cable between battery negative and the engine block. If it doesn't make a difference check the positive wiring to the starter and the PDC.

 

Update: After your responses, I elected to change my troubleshooting plan.
- Checked ground connections - everything looked as it should. No sign of damage, corrosion, etc.
- Replaced the battery. Strong engine start.

Voltmeter showed 14V across the battery (instrument panel meter showed slightly higher). Parked for a few minutes with the engine off. Started again with no issues.

What did I learn here:
- A variety of symptoms may present themselves because of low battery voltage.
- A battery test at Advance Auto isn't the same as a load test.
- I gained experience on changing out the starter in a 99 Ram 1500 5.2 - 15 minute job.

May my life be a lesson to others. Thanks for the help!