How to diagnose when your IDI starter will not turn the engine over

[Big Bart]

How to diagnose a Ford IDI pickup that will not turn over or turn over correctly. (Van’s are similar.)



This tech article is to help those less familiar with how your starter system works. It will help you through a set of tests to help you figure out what to do when your truck will not turn over or turn over correctly. It may be easier to read the PDF attached below.



You may have –

• A dead or low set of batteries. (Your truck came with two batteries.)
• A dead starter.
• A bad ignition switch.
• A bad starter solenoid. (NOTE - Your truck has 2 of them! One on the fender well, one on the starter itself.)
• A wiring issue.
• Bad battery connections. (Corroded or loose.)
• Bad battery leads. (Corroded, broken, or cut. Rock auto sells them.)
• Bad neutral safety switch. (On an Auto it’s on the tranny, on a stick on the dash by the clutch pedal.)
• A bad wire going to or from any of the above.
• A blown fuse.

Section 1 - So where do you start? Let’s determine first if you have good batteries. You need good batteries to turn over a diesel engine.

• Test the batteries while hooked together in the truck with a voltmeter. You should have at least +12V. (Batteries should have 12.4-12.6 if they are charged.) If you do not have at least 12 volts put a battery charger on. If you have over 10 volts likely the truck should crank anyhow.
• If you cannot get the pair of batteries charged up to 12 volts or above, unhook the battery terminals on both batteries, charge, and retest each battery individually. If one is bad you will want to replace both of them. Putting in a great battery with a decent battery will take a toll on the great battery. Having two good batteries means fast starts VS having a problem again in 6-18 months when the other weak battery dies.

Section 2 – Testing the starter solenoid on the fender well.

• Ok you have at least 12 volts but your truck will not turn over. (FYI if stuck on the side of the road, you can use this trick.) Next you will want to take a jumper cable and jump from the one big post on the starter solenoid on the fender well to the other big post. (See pic below.) This will send current to activate the solenoid on the starter. (Per above your IDI has two starter solenoids. One on the fender well and one on the starter. The one on the fender well is sending power to activate the starter solenoid on the starter which turns the starter o.) You will see some sparks but this is normal.
• If the truck cranks over the next step is to test if the starter solenoid on the fender well works. Hook one end of a jumper cable to the positive post on a battery. Now remove the wire from the small post of the starter solenoid on the fender well, touch the other end of the jumper cable to only the small post sticking out of the solenoid. (See pic below.)
• If the starter solenoid does not click, make sure the metal part that holds the solenoid to the truck and the bolts that hold it on are making a good ground. It gets the ground from the hold down bracket. Unhook the positive battery terminals on both batteries, loosen the starter solenoid bolts, clean bolts and hold down, re-install, and hook the batteries back up.
• If after cleaning the solenoid ground and applying +12v to the small terminal, if the solenoid does not click and the truck does not crank over, replace the starter solenoid on the fender well.
• If the solenoid does click but nothing happens replace the starter solenoid on the fender well. (You know from above if you jumped the two big posts the truck started, thus the solenoid is not working inside.)

• If the truck does not crank over when you jump the two large posts on the starter solenoid –
• Check all the battery connections. (Remove and clean with a wire brush or sand paper.)
• Check that the battery cables are in good shape, you have good connections at each battery, the truck block ground is clean and tight, (Negative.), the battery lead to the starter is clean and tight (Positive), the starter solenoid on the fender well has clean connections, the starter solenoid on the starter has a clean connection to the positive cable, and the wire that feeds power between the two starter solenoids is in good shape and has clean tight connections.
• If none of that worked, pull the starter and have it tested at a parts store or Alternator/Generator/Starter rebuild shop. Most likely it is dead.
• If you need to replace the starter many here prefer the Powermaster Starter as it is gear reduction, spins the engine faster, is well built, and makes for better starts. Also know there are I believe 3 other different models of starters that will fit our truck. (A/C Delco, Ford Motorcraft, and Mitsubishi but others can weigh in if there are more.) So each is a different shape but all will work.

Section 3 – Testing the ignition switch and solenoid activation circuit

• So your tests showed that the starter solenoid on the fender well works and the truck will turn over. But when you use the key the truck still will not start. You will want to –
• Take the small wire off the starter solenoid on the fender well and hook a multimeter or test light to it. When you turn the key to start, that wire should be getting +12v and your meter should show +12v or the test light should light.
• If your starter solenoid is working and this wire is getting 12v your truck will be starting now. (But low voltage from the ignition switch, a bad connector, bad batteries, voltage drop, or a marginal solenoid could still be causing a no start problem. Not likely, but possible, so keep this in the back of your mind.)

• If this wire is not getting +12v then you have an issue from the fuse block to the starter solenoid.
• 
  
• Start by testing if you are getting +12v to the safety neutral switch with the key in the start position.
• On an auto it’s on the tranny.
• On a stick it is a switch on the clutch pedal. (As I recall, I do not have a stick.)
• Keep in mind many folks have replaced their auto with a ZF5 or other stick. So the wiring could be that of a Automatic and just jumpered under the truck by the tranny. Check for a good jumpered connection.
• You will have to refer to an electrical wiring chart for your specific year, tranny, and model. Or ask in a thread on this site.

• If no power -
• You have a fuse out.
• Your ignition switch is bad or out of adjustment. (Or the rod from the lock cylinder to the ignition switch is having an issue.) Test and adjust the ignition switch or replace if needed. (On steering column way down by brake pedal, not up in the steering column.) Test that you have power coming to the switch and out the start lead when the key is in the start position.

• If you have power into the neutral safety switch but not out of it in park/neutral on a auto, or with the clutch in on a stick, then adjust or replace the neutral safety switch. (I have an auto, but as I recall that is how the stick neutral safety works.)
• If you do have power into and out of the neutral safety switch, but not to the starter solenoid wire on the fender well. You will need to trace the wire for a break or issue between the neutral safety switch and the fender well.

Most common issues in order of frequency.

• Bad starter solenoid on the fender well. (These just wear out every so many years and start cycles.)
• Bad ignition switch. These trucks are old and the ignition switches are wearing out. If yours is replace it, many have had starters stay on and do a lot of damage to the electrical system. They could not hear the starter was engaged over the diesel clatter. Some even knew they were bad, then someone else drove the truck, left the key in start mode accidently, and smoked the electrical. The starter goes from sucking power to creating lots of power at higher rpms.
• Bad batteries and or cables.
• Bad starter
• Bad neutral safety or wiring.

 

[Cant Write]

Thanks for the PDF version!! I will print this and laminate it!! Although I have no troubles now, Murphy is always lurking!!

 

[Big Bart]

Thanks for the PDF version!! I will print this and laminate it!! Although I have no troubles now, Murphy is always lurking!!

You are welcome. Unfortunately when I cut and pasted the info into this thread it killed the indentations. So the PDF will be easier to read and follow.

I hope all is well and Wally is ready for some family fun this summer. IM if in Newport this year and you want to catch up. We just got my son’s 67 Galaxie running so now I will have time to do some work on the truck again and will do a couple more tech articles. Need to do the A/C, front brakes, pop test the injectors, and put in a headlight relay kit. I bought it all 1.5 years ago and got caught up in my sons project but time to get to it.

 

[Cant Write]

With fuel prices lately, Wally has been sitting in the shade!!! I need to go give him some love. I threw my back out mid-May and Wally was the only thing I could drive to the 3rd appt (could NOT drive or even sit to the first two) as it's auto and my other two rigs are standards.

Next Monday-Wednesday we are going to Boggy Draw down by Dolores CO, and over to Hovenweep National Monument. Kids want to take Wally and I got that good feeling all over . I bought a fuel filter that bypasses the fuel bowl on the bottom and may try to see if that O-ring is my culprit. Other than that I need to look at the connections from the tank to the mechanical lift pump. AC works killer though!!

Rain is finally coming this weekend, so I need to get ice/water barrier on my shed roof before I ruin 9 sheets of 5/8's OSB. Buddy dropped 6 dump-truck loads of free dirt so I can have a level concrete pad in front of my shed. So I have been leveling that as well. Also cut 4 cords of wood, letting it bake in the sun, and will start splitting here shortly.

What a sweet car for a son to have and drive to school!! What drivetrain combo is in it? I do not know fords but assume SBF/C4/3.*** gears.

Excited to read more articles from you as they are well laid out and easy to follow/understand!!. I am not sure when we are coming to Newport next, but you will be on my list, and hang longer this time, maybe some grilling, couple beverages, and some light-wrenching/checking of things.

and you just sparked a thought, I think my timing is too far advanced. Cause I can load it on a hill and I think it will start "timing knock" at certain foot positions on the throttle. Kind of like making a gas engine detonate.

I am in dire need of a turbo up here, once above 6000', climbing power drops hard, and I live at 7500'.

 

[Big Bart]

His car has a Ford FE 390 big block engine, C6 tranny (3 speed), and I think he has a 3.55 or so in the rear. He thinks he is getting a wopping 8mpg! Filled up my F-150 today, $6.89 for regular unleaded. So he will learn quick what the value of a dollar is!

Would love to hang out next trip if you can carve out time. Just ping me if you have time.

Did you end up buying a timing device? We could do a little timing set session here if you have not by the next trip. But yes if you get a lot of clatter when laying into it could be your timing is off. But also make sure your timing avance is not getting power once the truck is warm. (Other electrical connector on the IP, it is supposed to loose power when the engine hits around 120*.)

Hopefully your fuel system upgrades will get rid of the bucking. FYI I have not had it happen but folks here discuss injector knock so listen if it is clatter (Hammers) or knocking.(Like a rod knock.) Also try filling your fuel filter with ATF, run for 2 minutes or so to get it into the IP and injectors, shut off and let it sit overnight. Many suggest it cleaned up their IP and injectors. We used to do that for MBZ diesels back in the day. (Ran then for 20 minutes on ATF, did not let them sit overnight.)

FYI, I would have thrown my back out in Mid April when the dirt arrived! So you lasted longer than I! Just know you have been infected with O-L-D and you will never be the same. You can't shake it or cure it, so just embrace it!