Replacing the Starter in an '06 4.0L engine. What am I in for?

I think my starter is dying. It doesn't like cool, or rainy days. I'll hop in the truck, turn the key, and get nothing. I'll pull the keys out, and try again, until eventually it fires. I'm not sure if these trucks have a separate solenoid or if it's integrated with the starter, but that's where I'm leaning. I had the truck throw a P0345 code a few weeks ago, when the problem initially surfaced, and that leads me to the starter. It's not the remote start that I have installed, as that was serviced when the code first showed up. I haven't had the code show up again, but I'll get a delay sometimes, where I turn the key, and it takes a second or two before the starter cranks, or I'll get nothing at all, and I have to pull the key, and try, and try, until it fires.

It looks like, if I take the drivers' side wheel off, and pull the mud guard in the wheel well, that I'll have access to the starter, but do I need to replace the whole thing, or would a solenoid, that I don't know where it is, be the culprit?

 

Replace as a whole or buy a rebuild kit.

 

It might also be the ignition switch itself. It might be the starter relay. It can be a bad battery connection (corroded/gunked up posts). A bad battery. A bad alternator that lets the battery charge drop too low. Or a bad cable from battery to starter (acid can get into cable and turn bright copper to a green powdery mess). Or of course the starter itself. There are several ways to diagnose. The simplest is piece by piece. IE a good heavy-duty cable from battery to starter bypassing the existing cable. A "delay" really sounds like a connection problem. That goo stuff greatly increases resistance, which greatly reduces available current to starter, and the starter has a huge current appetite.

If you want to just replace and test, I'd get prices for everything and start with the cheapest thing (probably the starter relay).

Good luck. Sometimes these can be tricky to isolate.

 

Thanks for the detailed reply. I just took a look, and there was some corrosion on the cable where it connects to the starter. And the end of the cable, down by the starter is turning green. I have a starter, but now I'm thinking it may just be corrosion. I guess the truck is almost 10 years old, so stuff like this is to be expected. I have 90 days to return the starter, but we have some weather coming which caused this to show up coming later this week. So if cleaning the cable and post don't work, I might replace the cable first, and take the starter back.

 

I was helping someone with a similar problem once and we were just getting clicks from the solenoid. But as I watched, I noticed a little steam from around the battery. Turned out to be the positive battery direct to starter cable, and the corrosion was bad. And wet. The steam was the moisture boiling off due to the high resistance, high current, high resulting temp in the cable. Some of those are easy to replace, a few are well beyond PITA. Ford makes quite a production of this on sn95 style mustangs. It is a complete mini-harness that only Ford sells. Don't need to say more...

 

Apparently, for our trucks, it's a fusible link wire. The original is encased in a massive engine harness, but I can just replace, and cut the originals off. $5 fix, if that's what it is. Thanks Robert.