Well, I got the truck back today. The mechanic said it started right up both Monday morning and Tuesday morning (today). This is encouraging because the temps were in the low 40's on Monday and Tue mornings. Without fail, since the weather cooled, the starter would fail to engage below 51 degrees. The next few mornings be the acid test.

As you may recall, the new mechanic said he found a wire that was almost completely broken. Only a small portion of the wire was intact. Well, I asked to see the wire. Come to find out, it was the terminal (stake on type) on the wire coming from the ignition key to the solenoid, not the wire itself. He cut it off, installed a new terminal and the starter has engaged correctly ever since. This tells me that one of several things was going on. The terminal had been flexed one time too many and developed a crack in it. When temps cooled down enough, too little electricity could flow to the solenoid to engage the starter. Or, the terminal got damaged during removal and remounting during the pigtail installation. If that is the case, it is my opinion that a poor connection existed originally at that solenoid terminal. Unfortunately, I have no way of knowing.

It appears the PATS system (expensive repair) does not appear to be the culprit, good news indeed.

 

Got the truck back today. It started both Monday and Tuesday morning with the temperature in the low 40's. It appears the "almost" broken wire was the culprit. The next few mornings will be the acid test. Thank goodness it was not an expensive PATS system problem (I hope).

 

Crap! The no start problem returned this AM with the colder temps (30 degrees). I waited for the temp to warm up to 52 degrees and the truck started right up. It was 3:30 PM. I drove it until the engine came up to temp before parking it. Tonight at 8:30, the starter failed to engage again. It had cooled down enough for the no start condition to return.

Now that I have learned the problem is triggered by cold temps, I began experimenting. Several days ago, I placed a trouble light w 75 watt bulb next to the starter and left it there overnight. I wanted to find out if keeping the starter/solenoid warm made a difference. It did not. So, tonight I placed a small portable electric heater inside the cab with the heating element aimed directly at the passenger side kick panel that contains the fuse panel. After 12 minutes, the starter engaged and she fired right up. What is in that fuse panel cavity that could cause this problem? Someone told me that the starter relay is in there, but I cannot confirm the truck even has a starter relay. Auto Zone, Advance Auto Parts, NAPA and O'reilly's do not list a starter relay for the truck. Does this mean it has no starter relay?

Any ideas/suggestions?

 

Further information. I got a Service Engine Light immediately after All Tune & Lube changed my tranny fluid. I accused them of doing something that caused the light. They investigated. With the engine running, the mechanic pulled on the fuse panel cover to look for a blown fuse and the engine stopped. He restarted the engine and pulled on a fuse ro remove it and the engine stopped again. It had our attention by that time, so we started the engine again and he pushed on the fuse box housing ever so lightly with the tip of his finger. Yep, the engine stopped. Just touching the wiring harness also caused the engine to stop.

Now I understood something was wrong inside the fuse panel and it made sense why the starter would not work when temps were low enough. I had the fuse panel (computerized power distribution module)replaced. Since then, the problem has not returned, but because the outside temperature has not dipped below 30 degrees F., the jury is still out. However, starting at 38 degrees is a significant imporvement over 50 degrees experienced earlier, so improvement has been seen.

The weather forecaster is predicting 26 degrees on Saturday, so that will be a very good test. I'm keeping my fingers crossed hoping the starter operates Sat AM. This weird crap is getting old.

 

Your thread has been interesting to read, problems like this, well to an old guy, its better than sex.

Years back I found a crimp on a terminal for the ground wre affecting several engine sensors. The terminal was crimped on securely to the wire but the insulation wasn't stripped back al all. The crimp pierced the insulation to make electrical contact but as the wire or insulation got colder the intermittent connection became evident. If you haven't yet, I suggest pulling down that fuse block to expose the back side where the wires attach and inspect every wire there. Good luck and keep us posted.

 

Yeah, things like this are interesting, but only if they are happening to someone else! Better than sex? Yikes! I'm older than most, but not quite there yet.

I closely examined the old fuse panel after we replaced it. There are/were no connections on the back. All wires coming in to the panel were in two wrist sized bundles of wires. Each bundle had its own gang plug which plugged into the side of the fuse panel, so the back was just smooth plastic. The inside of the thing, just behind the fuses themselves, had its own mini computer on one side of the box while a stack of 4 printed circuit boards were on the other side. Each board was separated from the other by approximately 1/8". It does not take much imagination to envision a hairline fracture in one of the soldered circuits that could easily cause the expanding & shrinking problem resulting in the no start condition. If it were in another, non critical circuit like the radio for instance, I doubt I would even look for it, let alone find and fix it.

Tomorrow morning will be a very good test. It is supposed to be about 28 degrees. I went outside a few minutes ago to test it and the starter engaged perfectly. The temperature was 36 degrees. I am cautiously optomistic.

 

Went outside at 7:00 AM Saturday while the temp was 28 degrees and the starter engaged perfectly. HOORAY!!!!!!!!!!!!!!

I sure hope it does not fail again when the temp drops under 20 degrees. That would be a bummer.

 

Final post on this issue. I went outside this morning when the temp was 14 degrees. The starter engaged perfectly. Problem solved.

Thanks, guys, for all the feed back during this trying process.

 

... well now are you bored with not having to work on the truck?? lol..

Good work man.. it takes a trooper to get through wiring gremilins