Gsmblue Posted August 9, 2019 Share Posted August 9, 2019 It had to happen. Been having a great run of form from the F150. Parked it at the airport on Sunday for a work trip, got back yesterday. Dead battery... Wife picked me up, brought the jumpstart box and all I got was rapid clicking from the solenoid. So we left the truck there and went home. It is only 25 mins away. Going back today with jump cables and a spare solenoid and I think I have a starter laying around, prob pack that just in case. Very frustrating as I am not sure what could have caused the draw and I am going to have to hunt down what is happening. There was nothing obviously left on and this has not happened before! Everything had been going so well with Eunice, but now I have to do a complete troubleshooting of the electrical system. I am thinking of starting with: Solenoid continuity check Alternator voltage check Alternator AC voltage check parasitic draw check (voltage drop on fuses) As always, all and any advice is welcome, as are witty anecdotes! Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 9, 2019 Share Posted August 9, 2019 A clicking start relay indicates that the battery is so low that the starter draw drops the voltage below the pull-in value for the relay. So it drops out and then comes back in as the draw goes away and the voltage comes back. I'd put checking the relay/solenoid on the back burner. I think the problem is one of: The battery has a shorted cell The alternator/regulator is bad and not charging Something is draining the battery. It could be the diode bridge is blown in the alternator and allowing current to flow in the "off" state. Or it might be something else that has failed. If you have a fully charged battery you can swap out and it'll probably run to get home. That'll allow you to check the alternator's output, both DC awa AC, although finding ripple on a charged battery may not be easy. And, you can test for parasitic draw. Link to comment Share on other sites More sharing options...
grumpin Posted August 9, 2019 Share Posted August 9, 2019 A clicking start relay indicates that the battery is so low that the starter draw drops the voltage below the pull-in value for the relay. So it drops out and then comes back in as the draw goes away and the voltage comes back. I'd put checking the relay/solenoid on the back burner. I think the problem is one of: The battery has a shorted cell The alternator/regulator is bad and not charging Something is draining the battery. It could be the diode bridge is blown in the alternator and allowing current to flow in the "off" state. Or it might be something else that has failed. If you have a fully charged battery you can swap out and it'll probably run to get home. That'll allow you to check the alternator's output, both DC awa AC, although finding ripple on a charged battery may not be easy. And, you can test for parasitic draw. I agree with Gary, my first thought was the condition of the battery. Link to comment Share on other sites More sharing options...
Gsmblue Posted August 9, 2019 Author Share Posted August 9, 2019 I agree with Gary, my first thought was the condition of the battery. Thank you gentlemen. the battery is about 18months old and is fully discharged at this time. Need to work out how it got to that state I guess. I will pack the multimeter and see if the alternator is giving any charge and whether it has an AC ripple. Good reminder, I need a decent multimeter... Looks like I will be heading out to it in about an hour, so I will report back later... Link to comment Share on other sites More sharing options...
1986F150Six Posted August 9, 2019 Share Posted August 9, 2019 Thank you gentlemen. the battery is about 18months old and is fully discharged at this time. Need to work out how it got to that state I guess. I will pack the multimeter and see if the alternator is giving any charge and whether it has an AC ripple. Good reminder, I need a decent multimeter... Looks like I will be heading out to it in about an hour, so I will report back later... Have you recently added anything [i.e. stereo amplifier] to you truck? Link to comment Share on other sites More sharing options...
Gsmblue Posted August 9, 2019 Author Share Posted August 9, 2019 Thank you gentlemen. the battery is about 18months old and is fully discharged at this time. Need to work out how it got to that state I guess. I will pack the multimeter and see if the alternator is giving any charge and whether it has an AC ripple. Good reminder, I need a decent multimeter... Looks like I will be heading out to it in about an hour, so I will report back later... Another thought, there is an external voltage regulator, could that be a gremlin source here? Link to comment Share on other sites More sharing options...
Gsmblue Posted August 9, 2019 Author Share Posted August 9, 2019 Have you recently added anything [i.e. stereo amplifier] to you truck? That is a great question. Nothing has been changed on this truck for a very long time. I froze the build last fall :) That is partly why I am frustrated. I have been running the AC a lot recently so that may have put a higher draw on the alternator maybe? I have visions of swapping the alternator out in the parking lot with y wife helping me! lol! Link to comment Share on other sites More sharing options...
1986F150Six Posted August 9, 2019 Share Posted August 9, 2019 Have you recently added anything [i.e. stereo amplifier] to you truck? That is a great question. Nothing has been changed on this truck for a very long time. I froze the build last fall :) That is partly why I am frustrated. I have been running the AC a lot recently so that may have put a higher draw on the alternator maybe? I have visions of swapping the alternator out in the parking lot with y wife helping me! lol! Is it possible the brake light switch is defective or the dome light was "on"? Link to comment Share on other sites More sharing options...
Gary Lewis Posted August 9, 2019 Share Posted August 9, 2019 Is it possible the brake light switch is defective or the dome light was "on"? Reminds me of two things. First, my grandtwins' other grandfather texted me the other day as the Subie's battery was dead. What could it be. My answer: Your grandkids have not met a button they did not push, and they FREQUENTLY play with the dome light switches. He texted back "That was it." And, I'm working a text string in the background. Bruno has a dome light that's on dimly. What could it be? A door pin switch is stuck almost closed? Must be the season? Link to comment Share on other sites More sharing options...
Gsmblue Posted August 9, 2019 Author Share Posted August 9, 2019 Is it possible the brake light switch is defective or the dome light was "on"? Reminds me of two things. First, my grandtwins' other grandfather texted me the other day as the Subie's battery was dead. What could it be. My answer: Your grandkids have not met a button they did not push, and they FREQUENTLY play with the dome light switches. He texted back "That was it." And, I'm working a text string in the background. Bruno has a dome light that's on dimly. What could it be? A door pin switch is stuck almost closed? Must be the season? Yes and yes. Anything and everything is possible at this point! Waiting for my wife to get back so we can go out and start trouble shooting. She is running late.... Link to comment Share on other sites More sharing options...
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