Truck stalls when hot

[Yeti_Owner]

Now it is stalling when I get out and shut the door just like the door is the off switch. I think I'm gonna have to get up close and personal with the wire harness. I'm so ready for a new truck lol

I can almost assure you it's either going to be a bad ground, or a voltage issue.

 

[EDGECRUSHER]

yeah it's gotta be! I've looked at the ground to the intake off the battery and the one on the firewall connecting the head to the frame and they all looked "intact". My truck is actually very clean for it's age. It hardly gets driven. Yet I'm gonna screw those grounds off, clean em up and prolly add some extras too.
Alternator seems to be keeping the battery up good but I guess I should check the output voltage. The coolant gauge that reads half of the temp it used to might also be a sign the voltage is whacky and maybe not the sender's fault at all.

Gotta love chasing electrical trouble. Takes forever, but then usually when you find the culprit you're like 'no wonder!'.lol

 

[Yeti_Owner]

Not as hard as you think. Before you yank them, get a multimeter. Put the negative lead on the negative terminal of the battery, set the multimeter to resistance, and test both ends of each ground. They should read pretty close to zero. The one that reads above 10 ohms or so (just a ballpark) is the one with a bad connection, or if it reads "infinite", its disconnected or broken.

If that sucker's reading 1/2 less than it used to, I'm now 99% percent sure it's a ground or voltage issue, probably the one right next to it on the t-stat housing. The temp sensor for the gauge is nothing more complex than a "thermistor". It is a variable resistor that changes it's resistance with the temperature. The colder it is, the higher the resistance. Lower voltage or a bad ground on the motor (which can be translated as "higher resistance=colder gauge reading, and I'm 99% sure you'll find) will cause exactly what you are seeing.

 

[EDGECRUSHER]

I added a 6ga ground from the frame to the ground point on the intake and one that runs from the same point on the frame to the firewall stud. No improvement. Next I'm gonna add one between that shared frame ground and run it to the block on one of the mechanical fuel pump bockoff bolts to better ground the block. I didn't meter the battery ground because it appeared to be in such good condition but I think I'll do that this time too.

After I had warmed it up and run it down the street and came back into my drive way it was surging in PARK. It didn't stall but then it was late and I didn't give it time too. Transmission still seems to want to lockup too easily. For example, put it into drive and you'd better have a good hold on that brake because it wants to pull!
Is there something I can do to check whether the the torque convertor is releasing? A TC problem doesn't explain surges/stalling from opening doors/hood. I keep going around in circles. lol I bet a brick would tell the story quickly.

I'm running out of tricks. I think it may be going in for a diagnostic if this doesn't help.

 

[Joey223]

I know it was a while ago, but did you figure out the problem? My truck is having similar issues, and I've replaced about everything you did.

 

[EDGECRUSHER]

I know it was a while ago, but did you figure out the problem? My truck is having similar issues, and I've replaced about everything you did.

I'm glad you asked because I hate leaving threads unfinished. Not to mention I had totally forgot I had this problem and had to read back through to try to remember what happened. The great thing was it was a crazy fix.

Something told me to tear into my glove box and have a look at my computer - maybe to replace it? I checked the computer and one of the connectors had worked loose. It had enough contact to run most of the time but if you slammed the door or the hood while it was idling it would jarr the connector enough to kill the engine before making contact again. I was very relieved to find such an easy fix in the end even though it took a very long time to find.

Chances are this isn't your problem, but you might as well check it out. You never know. Better get wiggling.

Good luck!