I have a 2003 4.7 L 1500 and I just recently replaced the starter and installed a block heater but still have a problem. It has been -20 the last few weeks and my original starter began acting up. I can turn my key, cycle the computer, but when I went to crank, the starter would engage for a quick second then disengage. Eventually I could get it to start after messing with it for 10 minutes in the cold. After putting up with this for a while I replaced the starter thinking that the cold killed it. While doing so I pulled the battery to check the charge on it and everything checked out.

After replacing the starter I thought the problem would be solved but I went to go crank it the next morning I had the same issue. (One fact I forgot to mention earlier, if I start it once in the day, it will not have the issue for 8-9 hours later) Thinking this issue might be caused by the extreme cold, I installed a lower radiator hose block heater. The next morning, same problem! The key turns, lights come on, gauges cycle I go to turn the key and hear the starter go then after half second it pulls out.(I cannot keep running the starter after this either, I have to reset the computer before trying again).
I hope you guys have some ideas for something I might be getting wrong. Help is much appreciated. If any of you guys would be interested in watching a video of the problem so you can hear it, email me at seekellbeast@gmail.com and I can get a video sent as I am new and don’t know how to post one. Thank you!

I’ll look into how to do that. Thanks! How would you best go about checking the computer side of it? I’m going to look up the solenoid/relay part.

I’ll check into that. We don’t think it’s the battery because we tested that earlier but if I can get it started today, I’ll take it to oriellys and have them test it with a load. What do you mean by starter ring? The teeth on the starter and the flywheel?

Also as an update: last night I was able to replace the 2nd starter with another one from Oriellys. Now with a total of 3 starters, all of them having the same problem I definitely think it is something else, electrical (either in the battery or wiring) or on the computer or ignition.

Thank you snow beast! I think the starter relay was the issue. I will update you guys tomorrow to help anyone else with this issue out. I replaced it for $10. Put the key in and held it on the forward position and I could actually hear it continue to spin. So pretty cheap and simple fix.

alright another update. Today even after replacing the solenoid relay yesterday when I went to start it in the morning it was very chuggy and didn’t start. So I hooked up our Dodge Durango battery to it and tried starting it (thinking it might be the battery) and nothing changed. This evening I tinkered with it a little bit and we eliminated the ignition wire and the solenoid relay by directly wiring the battery to the ignition switch on the starter. I just held the wires together with the key in the on position and it started up fine. So tomorrow I will see if when it doesn’t start the problem is somewhere in the wiring or computer of the ignition or relay by doing that again.