1978 F-250 rwd custom with a 460 and C6
Tried to start the vehicle the other day and got a no-start - a single click followed by nothing else. Since both the battery and starter solenoid were replaced in the last couple months I immediately assumed a faulty starter.

I removed the starter and bench tested it with a known good battery (also tested the battery and it was 12.8v). Absolutely nothing from the starter but some sparks. Pinion didn't move an inch. So, I replaced the starter with a remanufactured one. Installed the new starter and the same thing. Turn the key and click but nothing else...no-start situation again. I yanked the new starter off and bench tested it with a known good battery (reading 12.7v). Absolutely nothing on the bench but a couple sparks. The pinion gear spin a bit but very very slowly.

I brought both the new starter and the battery to the parts store and had them test both. The starter engaged and spun like a top on their machine. The battery tested absolutely fine too.

Am I going crazy here? I'm not sure why I can't get my starter motor to spin when plugged directly into a good 12v source. Negative to starter body, positive to positive connection on starter, like I've done on any other vehicle. Scratching my head. Looking for guidance.

 

NSS....remember the Neutral Safety Switch? Did you make sure it was in Park and try it, did you put it in Neutral and try it? The switch is down on the side of the transmission where the linkage attaches. But since you got at least one click, it could be your ignition switch.

 

Read and follow this post and it will point you to where the issue is.
https://www.ford-trucks.com/forums/1...w-starter.html

The other thing that new solenoid may be junk out of the box, the testing above will show it if so.
In the 80's truck area there is a on going post to track new bad solenoids.
I have fond after seeing a lot of posts of new solenoids going bad in a short time to get a good one.
If you check on line parts stores most list 2, a cheap and a more dollar one. Guess what you get what you pay for.
Also if you just walk in and ask for one they will give you the cheap one. You have to ASK for the better solenoid.

My 81 F100 would have the "clunk" once in a wile and if you kept trying it would start.
As part of my 4 year cab off frame rebuild all battery cables were replaced and run just like the factory with good connections.
I even pulled the old solenoid and cleaned the mounting as it needs a good ground to work and it was worst.
I got a top of the line NAPA solenoid. I asked for it and they were a little shocked and told me the price difference but I did not care.
It has been on almost a year and not a problem since.

So ASK for top of the line solenoid when replacing.
Good luck
Dave ----

 

A starter draws a whole lot of current. You must have a really tight connection. Jumper cables may not get there.

 

Are you sure you had the starter grounded properly? Put the cables on the starter first, then positive on positive post of battery and then if the starter is good, just touching the negative post should make it spin.

 

Did the parts store do a load test on the battery or just hook it to a meter? A battery can read good on voltage at rest but be junk under a load.

I just replaced what i though was a good battery because of that. I would charge it, it would take a charge and read high 12V, but I'd only get 1 or 2 starts out of it before it started cranking realllllllly slow and then I'd have to recharge it. So I started chasing what i thought were electrical gremlins killing it, because the truck sat alot... Redid all the battery connections and drivetrain grounds and started digging into the hacked under dash wiring and fuse box. I had to recharge the battery...again...so i dug out my old load tester, after I charged it, and although it was showing high 12V's at rest it would drop to around half capacity under load, then come back up slowly. I went and grabbed a new one and no problems since. Even the schmuck working at Wal-Mart was trying to tell me the battery was still good. I told him he could have it for the $12 core charge but he didn't bite...

 

We’re back with preliminary good news!

After painstakingly inspecting all the wiring for rodent damage or abrasion and deciphering the wiring diagrams we were able to locate on the internet, we still had a truck that most often would crank when the key was turned to START, but only for a moment. Maybe half a second.

We did find that disconnecting the BN-GN (see ckt diagram near top of this thread) wire that runs from the battery junction box to the solenoid on the starter, then putting the KEY to RUN and holding the BN-GN wire to +12V battery terminal would always start the motor. Then it ran as long as we wanted.

However, too many components are involved in the starter circuit to enable simple diagnostic efforts. The starting circuit involves:

CDIM (Circuit Deactivation Ignition Module
IGNITION SWITCH
OTIS DIODE (One Touch Ignition System)
PCM (Power Control Module)
BATTERY JUNCTION BOX (BJB)
STARTER MOTOR and SOLENOID
SMART JUNCTION BOX (SJB)

All of this was complicated by the fact that circuit diagram we had, post above, was WRONG.

We knew that OTIS was implicated in the problem but couldn’t figure out how.

Eventually we got smart and began proper diagnostic methods. To do this we:

1) Got a monthly DIY subscription to IDENTIFIX (correct circuit diagrams, detailed FORD diagnostics, etc.)
2) upgraded our OBDLink adapter to the newest Blue Tooth version
3) Updated FORSCAN to get all the body and engine proprietary system codes.

FORSCAN told us that truck had a bunch of codes set. Mostly related to effects of our DVM measurements throughout the truck. We cleared all of these. None of the codes gave us the diagnostic answer.

Then, we (my son, really) worked through the systematic FORD diagnostic routines within IDENTIFIX. Some of these involved using FORSCAN to run a built-in FORD diagnostic test. Other were DVM measurements while in START or RUN.

I won’t go into the details. We followed the FORD procedure in IDENTIFIX. 4 or 5 hours of careful measurements and….

BAD IGNITION SWITCH



FYI: for you OTIS aficionados. Three things will make OTIS stop cranking the engine.

1) the engine starts
2) The PCM times out (does not get signals indication the engine is running)
3) The ignition switch senses OFF

That is where we are at. I’ll up date when we put in a new switch.

 

How the hell is that of any use to the next person that comes along with the same questions you had? You're on a roll write it up !

 

I think AllenV posted in the wrong forum.

 

Thanks for the in-depth and detailed report Allen.
But are you sure you posted this to the correct thread?
This is the 73 to 79 forum, so not too many PCM, OBD, or any of the other stuff of what you speak matter here.
Still glad you’re narrowing it down though! :-)

 

I know this was you 1TonBasecamp .

 

Dang. Busted…🙄
But on the good side, I did get my post count up a couple on this slow Sunday.

 

I went thru 2 rebuilt starters in a very short time, gave up and bought a brand new one from rockauto.com
I'm about ready to do the same thing with the rebuilt alternator too.

 

You got to make sure you get the right reman. There is a 1/2" throw and 3/4" throw starter and both look the same. Some reman companies don't seem to differentiate between the two and either could be in the box.

 

Same starter, same battery, different test bench, Must have been your cables or cable ends.