Truck: 1985 Ford F-250 XLT with 460 (7.5l) Big Block engine (replaced at some point, 14,000 on this rebuilt engine).

Problem:

Started as a starting issue. I would be able to start and drive fine. Then, unexpectedly, with no previous symptoms of a problem, I would go out to the truck, turn the key and lose all power to the point that no lights would come on and the starter didn't even click. After a few minutes of sitting it would get enough of a charge to turn the lights on, but turning the key made it go out again. We looked for an ignition issue, but after a jump it would be fine. This happened maybe three times, but then stopped happening.

Now the battery, which was purchased new in January, is being drained. When this first started, I charged it at Les Schwab and it was fine, but drained again within a couple days. Took it to a local parts shop; an alternator test showed no output from the alternator at the battery. Voltage at the battery was around 12v, and testing on leads on alternator showed only slightly higher, but less than 13v. So I replaced the alternator and external regulator. Went to WalMart where i got the battery and had them test/charge it again, and it tested fine. But the batter drained within 24 hours. This last time it drained was while I was driving; i lost all accessories and only dim running/head-lights, but the truck engine was running fine on the alternator.

Possible Solutions:

I have not changed out the starter relay, and it looks pretty old. I don't see any corrosion on the wires from the alternator to the starter relay or to/from the regulator. I know from the Chilton electrical schematic that the alternator goes through the starter relay to get to the battery. With the first issue, where it basically discharged the battery from a full, no-starting-issues state, it screams starting relay or unintentional grounding. But perhaps it's the ignition box, which is another lead that passes through the starter relay.

Please give me your opinion of what the source of my frustration might be!

 

Voltage regulator perhaps?
Have you pulled fuses one by one while checking if the battery has a draw on it with the truck shut off?
My $0.02 worth.
Good luck - I hate electrical gremlins.

 

I had a bad "reman" alt on my diesel, put it on and went out thenext day to dead batteries, opened the hood and i could see those little heat waves coming off the alt, drained 2 1100ca batteries through it good thing it didn't start a fire. Check the regulator again, is it grounded correctly? There should be a ground wire going to the mounting screw. But keep in mind rebuilt alts can have issues

 

Are you sure they gave you the correct alternator? On my 86 the alt went bad and it had at least 6 different alternators that would fit (so the parts store said) Mine had the internal regulator & i bought a new harness as well. After about a week the alt stopped charging (again) so i grabbed an older alt and external regulator & harness from a junk yard and drove trouble free for the rest of the trucks life.

 

I have some troubleshooting help here;
Ford Truck Enthusiasts Forums - Grubbworm's Album: Troubleshooting help, for anyone that needs it.
You might want to try this 3-point voltmeter test first;







Let me know if any of this helps.

 

New so far:

Alternator (65 amp)
External regulator
Starter relay
Ground wire to alternator (which i found out was not there before)

And the drain continues

I had my neighbor grab a voltage meter for me (as I have to walk a quarter mile every time I need a part or tool). After replacing everything above and checking all wires for any corrosion or exposed wire, we did the neg-terminal-to-neg-wire test, with the positive still attached, and found a 10.3 volt drain, so a full battery drain from something. This with the fact that the battery still gets 12 volts but won't start. Dome light comes on fine when battery is attached. I have some looseness in the pos terminal, but it doesn't explain that much of a battery drain.

My next step is the fuse elimination process, but I will need to go get a wire scour pad (to clean the grounding site on the frame) and a better multimeter, as well as a new ignition connector - the slip-on connector on the last starter relay was smaller than the current starter relay's terminal, and shoving it on there didn't really work well, so I'm just replacing the connector altogether with an eye-style connector that attaches with a nut.

Haven't been able to jump the thing so I have no idea if my charging system works or not. Will check that too once it starts running.

I will post pics as I can. Thanks for all the help. I'm on the right track, but this is the tough stuff that just drives you batty.

 

Yep i hate electrical stuff, the only way you know its fixed is if it doesn't do it again.

 

I realized that the alternator never had a ground to the frame, no ground wire at all, so I never hooked one up. I made a ground wire and hooked it to the frame bolt, but the battery is too dead to test the charging system. Turns out as well that the "battery drain" the neighbor claims I had was volts, not amps. I had no amperage at all in the battery, though I'm getting 11.63 volts.

I tried jumping the battery, but it was so low it kept trying to start even when I turned the key off. I assume it had enough power to open the ignition circuit but not enough to close it.

Today I'm walking my battery down to get it charged, then I'll let you know if the battery is charging.

 

So a lot has happened since the last post. Charging the battery didn't allow any change in voltage; in fact, the voltage went from 12v even wiht the truck off to 11.86v with it running. So I took the alternator and the voltage regulator in to the parts store to test. Found out there's no test for the voltage regulator, but the alternator tested fine. Looked at the regulator closely, there was an imperfection, like a bump, on the epoxy on the inside cavity. The epoxy has to have an even surface to conduct correctly. I replaced the regulator and the voltage on the same alternator was perfect, 14.05v. So all well and done right?

Tonight I had the same issue as before where I tried to start the truck (after having driven it for a while). It bogged down to where the crank was turning really slow, then immediately sped back up to normal cranking speed, but then wouldn't stop turning, even though I turned the ignition off. This time, though, with a charged battery, it turned and turned, the engine popping and never really starting. I ran and popped the hood, saw smoke on the neg battery lead, and grabbed for the lead to yank it off. I burned my fingertips. Then ran and got the closest pliers I could find, got the nut off the lead. All that time as i touched the lead with the pliers it was sparking and sizzling. Once I finally got the lead wire off it flew off, having finally melted through between the wire harness and the battery lead. The wire started melting the plastic on the top of the battery where the wire was touching the surface of the battery. Needless to say, with no negative battery connector, it's dead in the driveway.

I looked elsewhere here and in Google searches, and everyone says the same thing: cheap aftermarket starter relay that probably welded the connections at some point where they never close the circuit to start. Some others point at a bad ignition switch spring under the dash, or a bad ignition starter switch at the ignition box side.

The cost of my starter relay: $6.99 at Cost Less Auto Parts here in Vancouver, WA. it's the only one they had. My old one I threw out, figuring it was too old, but it was Motorcraft, so I am kicking myself right now because it was probably fine and a better brand.

I don't have the money for another Motorcraft, which is probably about $40, so I will try another starter solenoid relay. Otherwise the charging system works.

It's possible the weld happened the first time it had issues starting then never stopping turning. At that point I was jumping it with another vehicle and the voltage regulator was the faulty one. Too much voltage could have sent too much amperage through the relay and welded it slightly. But the lack of amps in the battery stopped it from welding the rest of the way.

So it's back to the parts store, a new alternator, a new set of battery connectors and a look through the wires to make sure none are melted.

The gremlin will not take me alive. I will triumph, burnt finger by burnt finger.

 

Man, there's a good chance you're causing more damage than already exists....

It sounds like you have multiple problems but I shall address only the stuck starter motor here.

The starter motors are designed to operate in short bursts only, for a limited amount of time each time. The Owner's manual I think says no more than 45 seconds before letting it cool for 5 minutes.

This is kinda like a windshield washer pump, they're designed to work in short bursts and will burn out with continuous usage.

The voltage regulator controls only how much voltage is supplied to the battery from the alternator when the engine is running.

Your wires overheating and melting are a concern that you should fix. This is caused by heat, which is caused by a lot of amperage being drawn through too small of a conductor.

The throughput capacity of the circuit as a whole is effectively reduced when bad connections are introduced.

Same thing when the cables themselves get moisture in them, the copper inside turns green and corrodes and a white powder (resistance) develops between the strands.

Diagnosing your sticking starter

When the starter continues to operate with the key switch off, remove the small red/blue-stripe wire from the solenoid... if the starter keeps turnning, the problem exists between the battery <-> solenoid <-> starter ans is most likely a solenoid that welded itself together and sharply banging on it may free it up.

If the starter shuts off as soon as you pull that small wire, this indicates the problem exists between the solenoid and column-mounted ignition switch.

For these purposes, the only thing done by turning the key to START is to energize that red/blue-stripe wire, this causes the solenoid to close and connect the two fat cables together. (Some systems also utilize another small solenoid terminal to feed full battery voltage to the ignition system for start-up purposes.)

Someday I hope to find a burnt-up solenoid that provides for more dramatic pictures (I had one once but didn't photograph it) but, until I find one, here are some pictures of what happens to the insides of those solenoids, notice the pitting & black at the connection points:

 

Always buy an older style starter solenoid with the large posts that stick out the sides.

The newer end mounted style, have very small internal power contacts. The internal contacts are much smaller than the copper posts and the battery cables that connect to the solenoid. The small contacts will create an excessive voltage drop across the starter solenoid. Internally it looks like something that was designed to fail.

Here is a You Tube video that shows the insides of the newer relay.

Taking Apart A Ford Starter Solenoid



If you look at the photos shown above of the old style starter solenoid it has a large copper washer attached to the coil operated plunger. The plunger/washer is designed to rotate with each use so as not to wear the copper washer in one spot. Because of this rotation it is important to mount the relay vertically so the plunger is balanced.
In the old days I used to repair these by removing the copper battery cable studs and rotating them 180 deg. You can clean up the pitting on the large copper washer or just turn the washer over and thus double the life of the relay. Not to mention the old part was probably made better than the newer parts currently available at the parts store.

If you look closely at the first photo above, you will see where the other small terminal would be. When the large copper washer is pulled down, when the solenoid is energized, it hits the shoulder and thus provides battery voltage output to the small terminal to power the coil positive while the solenoid is engaged. On newer trucks this connection is not needed or used as the Key Switch provides this power source for the coil during cranking.

Also the “sticking relay” can be caused by the large copper washer hitting the power input shoulder connection on the inside of the relay.

Jim

 

Actually that smaller solenoid with the battery posts out the front is for the 4.9L 1980-1983, among other applications. I still have a motorcraft solenoid of this type on my truck.

You can replace it with this...

Starter Solenoid: Motorcraft: SW-1507-B: E7HZ-11450-A

I entered the part number: E7HZ11450A into www.partguyed.com and he has one cheaper than suggested retail. He's also a Ford Truck Enthusiast sponsor.