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Hello, my name is William and I recently got my old '84 F250 running a couple months ago, but ran into a problem. I looked through some of the forums, and saw one that seemed close, posted by slurpee. However, I'm not sure my problem is the same. Engine temperature seems to have no bearing at all.
I was driving on the freeway, and turned the lights on and my engine and all power in the cab immediately died. I attempted to restart the engine and got nothing. Except for the glowplugs (which were hardwired to a button in the cab), the brake lights and the emergency flashers, nothing electrical worked.
Both batteries are at 12.5V, so that ruled out my thought that the alternator was bad. Battery terminals are secure, belts are not loose, all of the fuses are good, all connections to the starter and starter relay are tight. I traced down all of the wires I thought were associated with power and see no evident wear that would ground.
I searched on-line and do not see any references to any other fuses like a master fuse, so I don't know what else to look for. I had a mobile mechanic look at it and he didn't have a clue. Any recommendations on what to look for next? The good news is I moved out to Virginia a couple of weeks ago, and this didn't happen during my road trip! Thanks.
Have you checked the fusible link located on the battery terminal stud of the remote starter solenoid (passenger fender)? Maybe the fusible link has partially failed making a connection for low power demands and failing when more demand is placed on it. The Orange wire feeds the headlights, and some of the circuits in the fuse box, the Red wire (link) feeds some of the exterior lighting circuits - but if you losing all power I would first suspect the connection at the solenoid stud is corroded or loose.
If you can get the problem to occur in your driveway, you can easily probe the wires to determine where the power is lost.
If it isn't one of the fusible links then check the grounds. There is one from the battery to the engine and on to the frame. And there should be one from the rear of the engine to the cab near the windshield wiper motor.
If not the grounds then check the integrity of each cable, both positive and negative, from the battery. Sometimes the connection to the battery is good but the cable to the connector is bad. I recently had that where every once in a while the engine would crank slowly. But everything looked good. Until one day I had the hood up when it happened and smoke curled up from the positive battery cable at the battery end. Turned out the cable-to-terminal connection was poor.
Thats what it sounds like, ford needs body grounds, and alot of them, thats why they come right off the battery to the fender, clean and tighten all your main battery cables anyway, even if they look good, it's the inside that makes the connection not the outside, Again check all fuse links, a slight tug on them will show a bad one. but since your losing everything, battery connections, grounds and do it right. Of you will be stuck on your next trip.
Both batteries are at 12.5V, so that ruled out my thought that the alternator was bad. Battery terminals are secure, belts are not loose, all of the fuses are good, all connections to the starter and starter relay are tight. I traced down all of the wires I thought were associated with power and see no evident wear that would ground.
If my battery was at 12.5v when running I would buy me a new alternator, because my battery in all my cars is above 13.8v when running(even with full headlights and air condition blower active).
If my battery was at 12.5v when running I would buy me a new alternator, because my battery in all my cars is above 13.8v when running(even with full headlights and air condition blower active).
The truck was not running, and even though the batteries had 12.5 nothing worked, except the glow plugs, when he gets it running than he can check bat voltage
I had a similar incident with my '84 F-150 and it turned out that one of the spade connectors inside a 4 prong plug had corroded away. Of course it was the connector for the large main power wire, the one with the fusible link. Connected the wires outside the plug and away we went.
If at any time I turn off my car, or my car dies, and i see a 12.5 volts on my multimeter from my car battery, either my alternator or my battery is toast. I bet alternator is toast.
Patrick, check your math. 12.5 is 80% of 15.625 and that would already run into overcharging with a running engine.
Read carefully. The engine was not running. 12.5 V on a resting battery would be normal in anyone's book.
Also note fusible links are either intact or open. Your statements about voltage and current are incorrect and misleading. Such conditions would indicate a resistive state which is extremely unlikely.
OP did not specify, but his profile says 84 F250 and glow plugs indicate diesel, so we are likely dealing with a 6.9 IDI. Mechanical injection, so we don't have any ECU concerns. Everything died when he turned his lights on which strongly suggests the primary fusible link at the starter relay. Also would suggest a short circuit in his headlight circuits. Grounds are important, but not likely in this case. His add on glow plug wiring works and there are at least 2 factory ground paths for everything else. Having both fail simultaneously would be extremely unlikely and would also have affected the glow plugs which likely ground to the engine block.
4 pin plug mentioned sounds promising. Would this be the dreaded alternator plug?
About troubleshooting this problem... I always go for simple things first. Which having said that might seem like the first thing would be fusible link. But I trust fusible links more than battery, and more than alternators.
Then since his battery was weak (12.5 volts after being in a running car is at most 80% charged) since ??bad alternator?? he couldn't even crank/restart the engine. My thoughts are glow plugs can "work" even if the battery is 75% gone.
and after typing so much, without a reply from original poster i am going to leave this thread until we get more info. like a load test on the batteries..
Diesel engines with mechanical injection shut off by fuel starvation. This is accomplished on a 6.9 IDI with a fuel shut off solenoid located on the injector pump. +12V is required to keep the fuel running. Remove the power, solenoid closes valve and engine shuts down. No ECU required.
Your battery charts provide, at best, a guesstimate of the charge remaining in a battery. They are not designed to provide any valid info as to the state of the charging system. 80% charge in a battery could be normal depending on what loads were present prior to the condition reported by the OP. You may also notice that 12.5V or 80% is well within the green zones on your charts. Green = good.
How do I know this? I am a retired railroad signal supervisor. It was my business for many years to ensure battery systems remained in top notch operating condition in order to operate safety critical track equipment including railroad public grade crossings. If I did not do my job properly, people could die. I take it seriously.
On fusible links, you must understand that the purpose of a fusible link is to open in the event of excessive current demand. This is accomplished by designing a weak spot into the current path, i.e. the fusible link. It is nothing more than a piece of wire, smaller in gauge than the circuit it is designed to protect. It has metallurgy that promotes the wire to melt quickly and disconnect the power. It is covered in rubber insulation to contain this meltdown and reduce the chance of fire. The wire does not "fail partially".
I continue to post to correct the spread of misinformation.
I have to agree 100% with not enough trucks.
There is a big difference between a standby deep cycle battery and a starting battery.
12.5x volts is all that will be seen -or wanted- in an 'at rest' automotive battery.
A fusible link is just that. (a fuse)
It either is, or it isn't.
There may be a loose or corroded conection that will not pass enough current when called upon.
If a fusible link is blown no electrons will flow in that circuit.
08-14-2014, 08:21 AM
