2005 F150 V8 triton: Background, I use a phone charger and Garmin GPS unit that are plugged into the dashboard lighter receptacle. That is not switched so I need to remember to pull the plug when I turn off the motor. I forgot recently and the battery died. I had problems with my battery charger but did get the motor running by jumping from my car battery.

I went to get gas and run the motor to be sure the battery was charged, I got to the gas station pump when the battery light, check engine light, and a wrench symbol light come on in the instrument panel, and a "check gauges" note showed in the monitor window. Not sure the engine would start if I turned it off, I came back home with not filling the tank. The lights went out after a little while. They came back on, and I pulled the plug to the two units mentioned above and the lights went out again. I stopped at an Advance Auto and they checked the alternator and battery and all looked real good.

I noticed a headlight bulb was out while there. I came back home and the lights mentioned above came on. I have a couple testers that plug in the code reader port and they both said "no codes". I cleared them anyway.

What could be causing this? It did not a happen before this time of forgetting the plug. I forgot to mention that one time when the lights were on I noticed all gauges were working fine except the temperature gauge, it stayed as far low as possible, when the warning lights went out, it worked fine.

I understand the computer needs to relearn some memory when power is off for a while, could that be the case here? It would be wonderful, if it was that easy. I had to worry with my car also today so did not have a lot of time to check much.

Two questions here, what could be causing this, and if the caution lights are somewhat intermittent will it hurt to drive it?

 

No mention of how old the battery is.....

 

Not sure that matters a whole lot, itI was checked yesterday and showed good. Of courses, the newer it is the better you would expect. I brought this truck August t 2018, do not recall getting a new battery but I may have.

Anyway, hoping for the best today, I drove to the same gas station I went to yesterday and no warning lights came on. I drove down with no heat, no lights, the cigarette lighter plug unplugged. On the way back home I plugged in the cigarette lighter accessories, no warning lights. After a bit I turned on the heat and defrost, no warning lights. Then when closer home turned on headlights., no warning lights.


checked recently, no date on the battery

 

I was just thinking that if the battery was old and worn out that it would cause the dead battery syndrome in the morning. Cell phone chargers don't kill batteries. You didn't mention the battery was newer or that it was tested (properly) the day before in your original writeup. Figured it was good to ask if you were troubleshooting a truck problem that would likely be a bad battery.

 

I have never had the battery light, CEL and wrench icon light up when my battery went dead. Might be something wrong with your alternator.

 

was thinking alt also... do you know how to use a multi meter Jay ?

 

Apparently it may be be a transient problem. Maybe the computer needed to relearn something due to power drain . It has not shown any lights since then. I'll keep an eye on it.

 

got you...