I have a 1978 F150 Ranger Explorer that was running when I bought it in June. Cranked reliably multiple times. Seemed like labored turning over at times, but nothing more than that. Starter was replaced not long ago by previous owner. Drove it fine several times. Got it home in the driveway one day and then all of sudden no turning over, no lights, no anything other than horn (Horn works as it is directly wired aftermarket to the battery.) While pushing it into the garage with my Jeep, the brake lights did come on just momentarily when the truck went over the lip into the garage (thinking maybe indication of a loose connection). I checked the battery and it read right at 12.75 - 13 V. Tried jumping the starter solenoid and nothing at all. Checked/wire brushed the ground connection from the frame to the engine block. Checked/wire brushed the connection from the engine block to the (-) wire that goes directly to the battery. Took a jumper cable and connected it to the terminal on the starter that is supplied from the wire coming from the starter solenoid. Then took the other end of the jumper cable and connected it to the red positive post and got nothing other than a little bit of crackling and smoking at the post. (Red wire runs to the solenoid). I am thinking maybe there is a bad ground somewhere or loose connection maybe? Any ideas of what it could be?

 

Hey Karina, seems you have covered bout all in checking why no crank, no any thing. You need to go over once more, the battery cables, solenoid and what happens to the battery voltage when you try to engage the starter. Seems your have a DVOM (volt meter)

1- Disconnect the cable to the starter at the solenoid. Test batt voltage pos to neg posts, NOT the terminals on the cables, post to post. Now test on cable term to cable term on the batt, should be the same as posts. Now leave neg lead of volt meter on batt, then hook the pos lead to the solenoid stud you removed the cable to starter from. Engage the solenoid with a jumper wire, pos side batt to the S term on solenoid. The solenoid should engage with a defined snap and the volt meter should read the same as batt voltage, possibly a tenth or two lower because of energizing the solenoid. All Good???

2- Hook up the cable to the starter. Voltmeter hooked up to battery again. Engage the solenoid with the jumper wire again, while watching the Voltmeter, the engine should crank over. If engine does NOT CRANK, look at the voltmeter reading. Does it take a nosedive or just lose a little voltage????

3- IF IT takes a nosedive, 1, The Starter motor has a dead short ( even if a recent rebuilt replacement). 2, The Starter may be jammed into the flywheel. Try turning the engine over by hand at the bolt in center of front damper, it should turn easy. If NO try turning engine backward. Still difficult, remove the starter and check again that engine turns free.
Very possible the incorrect starter may have been installed as there where different flywheels with different amounts of teeth.

A lot of writing, but not a lot of time checking all, a positive process of elimination of causes. Getting the engine cranking first, then after address any other maladies.

Cap

 

Thanks Cap! I will try all of your suggestions. Appreciate the help

 

Okay, so update:


1. Battery posts read 12.66 V. Battery terminals read 12.66 V.
Got a very defined snap every time I jumped it. Jumping and holding two leads was interesting. The reading across the solenoid was about 12.2-12.3 V with jumper wire engaged.
Then, hooked wire to starter back up. Tried jumping. NOTHING. No snap. Unhooked the wire again and repeated the first jumper test. Still nothing.
I guess the starter solenoid may be faulty?

I randomly tried turning the headlights on here and there before the solenoid test when I had been unhooking and rebooking the battery terminals earlier and twice they came on and stayed on. Tried cranking both of those time and “clunk”. But nothing else and headlights went out. Can that be a symptom of a bad starter solenoid?

 

Karina, "Jumping and holding two leads was interesting." LOL, your not a magician ?? Guess you need a helper.. With My DVOM,I have 2 sets of leads, one set probes, the other alligator clips ( the third and fourth hand helper ).

As the solenoid is case grounded, be sure where it bolts to the fender well is clean, no corrosion. DVOM, on Ohms, one probe neg batt term, other touch metal part of solenoid that is mounting bracket, not the bolt that holds it to the fender well. should be no resistance. if resistance, clean the mounting real well.

Does your truck have a ground wire from the engine to the firewall and it's intact, not broken, loose??

Disconnect the cable at the starter, attach to nothing, engage the solenoid, loud click?? If yes, voltmeter to battery neg and other lead to the cable disconnected from the starter, engage solenoid, ( loud click ), meter should read battery voltage ( may need 4 hands ). No click, solenoid is really suspect. If yes, remove the starter and on the ground with good booster cables test it, neg to starter case, pos to the stud cable goes on. Put the nut on the stud so you don't damage the threads when you touch the booster cable to it. Prob best pos booster on the nut and touch the neg booster to the case, starter should snap, jump and spin real strong. It should also thro the starter drive forward. If lazy and or no spin the starter may have a dead short in it.

You didn't say if you tried to turn the engine over by hand. If you Didn't, do it, before removing the starter.

 

Thanks, Cap!

 

Update:

I tried rotating the engine. It rotated CCW facing from front end with a breaker bar. Good bit of force to turn it, but turned no problem repeatedly.

Installed brand new starter solenoid and power wire brushed where it mounts and also the bolts. Hooked up battery. Tried lights only, success! Then turned key. Same result as always. “Tunk” then nothing. Headlights go out and won’t come back on.

Took starter off. Bench tested it with jumper cables. Spins like a champ. Put starter back on. Put jumper cables directly to starter just like bench test. Engine tries to turnover. So now starter solenoid and starter themselves are ruled out.

I also tried my Jeep battery in the truck just in case and I know it was good as I drove it earlier. Same result as always. “Tunk” then nothing.

Going to go get alternator tested just to help rule that out.

Trying to think of what else it could be at this point. Could it be the ignition, ignition control module, simply a short somewhere in the loom? Anything else?

I also forgot to mention that I proved continuity all the way from the firewall to the negative post on the battery with my multimeter by putting one lead on the firewall, and the other lead on the negative post. Meaning I have continuity from firewall through grounding strap through engine block through cable from block to negative post. I also proved continuity from the starter body all the way back to the negative post on the battery by putting one lead on the starter body and the other lead on the negative post.

The lights run just fine and continuously after I have let the battery rest unhooked for a while and then re-hook it up. As soon as I turn the key is when it “thinks” and throws it again. Then lights won’t come back on at all then until battery has been disconnected and then reconnected. I’m thinking maybe it could be ignition related?

I really appreciate all of your knowledge and insight into this!

 

This getting STUMPIER, how's that for a word.

Your battery cables, are they like OEM, meaning they Don't Have replacement terminals that clamp on the cable after cutting off the original terminal??

Don't remember if you ever answered this. With the voltmeter hooked to the battery, engage the starter, watching the volt meter. Does it lose a small amount of voltage or does the voltage take a nose dive, like to 9,8,7 volts.

Minor loss of voltage, battery cable(s) not covering the load. Big voltage loss, again, starter??? Was the starter installed by PO a rebuilt or just another starter put in?? If a rebuilt is there a tag or decal identifying it?? Make?? Part #??

Now this is going in a totally different direction. First, what engine are we dealing with, don't remember it being mentioned. 300-6, 351M-400-8?? Is it the stock engine to the Truck?? Standard or Automatic??
Your engine has a Dura-Spark II ignition system. The Control Module on the driver side fender well has a built in feature that retards the spark when cranking the engine. Possibly that may not be happening and kicking the engine back. SO, when you try to crank the engine, does it turn for a second or less, then complete stop, or just doesn't move at all with a thunk??

 

make sure you have good clean ground connections , if the main battery to motor and frame are dirty corroded they won't crank there also should be a ground from the block to body/frame that goes bad making for a no crank

 

Did not pay attention to "I tried rotating the engine. It rotated CCW facing from front end with a breaker bar. Good bit of force to turn it, but turned no problem repeatedly." ??

So you turned back against Normal Rotation. It is what you would do IF you had a Jammed starter. Did you try turning it CW , normal rotation FIRST ?? Most engines, you could turn the engine with just a little hand tension on the belt and turning using the fan with you other hand. Of course you can't do that with a free wheeling fan.

 

FTZ HAIC. Thanks for your comment. A reason I ask what the volt meter reads when trying to start. Does it draw WAY Down suggesting a badly worn, shorted or stuck Starter, or just show 1 to 2 volt drop suggesting something is NOT supplying the load such as cables, as you suggested or bad grounds.

 

Hey guys, this is Karina's husband now writing this. I just made my own profile but can't reply on here yet sadly. I was the one actually doing the dirty work for the above testing mentioned. Got it cranking on Saturday. It turns out it was the positive battery cable exactly as FTZ HAIC described. Once I put a brand new cable from Advance, it cranked right up no problem. I wish I had read FTZ HAIC's post BEFORE figuring it out separately. Frustrating that it was so simple but relieved it was such an easy and cheap fix.

I thought I had ruled out that cable, as I did the voltage test, looked at the cable surface that mates with the post and so on and thought it looked good, but it must have been corrosion that couldn't be seen like he said, maybe in the terminal. I cut the jacketing off before throwing the cable away and the wire underneath looked immaculate to me. This was a good lesson for me that voltage doesn't prove everything.

I still find it strange that part way through all of this, the lights would run just fine, turn key, then lights won't come back on at all. I get that the cable didn't have a good enough connection for the large current to start, but I find it most strange that trying to start with the key basically "threw" the lights out after that. I have never had something personally like that that I can remember. Either way, learned a lot more about electrical than I ever have. Tremendous thanks to iicap and everyone else for the help!

 

Not sure if the cables had been replaced or were stock. They definitely showed some age, but not sure if 43 years or not. They were OEM style, though, with wires soldered into the terminals and not clamped.

Thanks for the excellent advice. I had not tried the nosedive test and should have. I didn't do it at the time while trying to test it by myself since I couldn't hold the leads and start it at the same time while my wife wasn't available. I need to get some other alligator leads and so on like you mentioned before.

It is not the stock engine. It was replaced by a previous owner. It is either a 351M or 400. I need to pull a spark plug, I think, to definitively prove if a 351 or 400 but haven't yet. It is an automatic C6.