Help! 78 II has no power to any electrical except headlights and taillights and hazards.

[JackH]

Background: Hello all, I just bought a 2.8L II in December and ran into some problems. First, i am on a military base so getting this fixed sooner rather than later would be ideal. I have already replaced the battery cables, starter solenoid, duraspark module, fuses, cap and rotor, and electrical ignition switch (the one at the bottom of steering column). The brown wire for the headlight/taillight circuit does what it's supposed to so.

The Problem: No crank from key, no dash lights, no turn signals, no horn, no radio, no open door buzzer, no wipers, no wiper fluid spray. The engine turns over remarkably well when jumped off of the positive side of the starter solenoid. there is no "gallop" but still doesn't fire off with starting fluid down the carb so is that possibly because the duraspark isn't allowing power to the coil or distributor? One thing i noticed is on the side of the 2700VV carb near the throttle cable there is an electrical thing that seems to move back and forth when i connect/ disconnect the battery or when i cycle the key from off to run. The picture attached has the piece circled in red. *note: the picture of the carb is from google not my actual car but the piece is the same.

Any and all help is greatly appreciated!!
-Jack H

 

[extra_stout]

Welcome to the forum!
We want to see pictures of the car too
You have a fuse box below the dash board on the driver side. I would start checking if you can measure voltage their. And if the contacts of the fuses are corroded or if this is a bigger problem.
I think your right, that your ignition is not working of this bigger electrical issue...
Here is a trouble shooting guide for the duraspark if you have voltage at the fuse box:

How to Troubleshoot a 1977 Ford Duraspark ll Ignition System

The Duraspark II ignition system debuted in 1976 with the intent to make substantial increases in secondary voltage and extend system maintenance intervals. Spark plug gaps were widened to take advantage of the heightened current and to prolong spark plug life. Special testers were devised at...

itstillruns.com

The electrical thing at the carb is as far as is understand just for adjustment of the idle speed. No need to mess with it right now.

 

[Mcmahst]

That electrical device on the carb is suppose to ensure the throttle plates close completely when you shut the car off, to prevent dieseling. Just info.

 

[LILCBRA]

Welcome to the group!

The best advice I can give right now is to ensure all connections are clean and are making good contact. Next suggestion is to check different circuits to make sure you're getting power when you're supposed to. A test light is a good start, but a good meter would be better. I used to have wiring diagrams but I don't know if I have them anymore. One of the repair manuals has them although I don't recall which one - I think it was the Haynes manual. I think it would help you quite a bit if you can get your hands on one.

Without knowing much more about your car, there's one situation that I've personally had that could be an issue. I had 2 full sets of harnesses when I put my car back together and ended up mismatching the engine and body harness. It's been probably 20 years now, but iirc it wouldn't turn over with the key. I chased my tail for quite a while til I swapped the engine harnesses and everything worked as it should. I can only assume that that's not what's happening in your case, but it IS something to keep in mind for future reference....

 

[extra_stout]

 

[85GTStangGuy]

That electrical device on the carb is suppose to ensure the throttle plates close completely when you shut the car off, to prevent dieseling. Just info.

It's not a "idle-kicker-upper" to raise the idle if the a/c is on??

 

[LILCBRA]

Had to get up from the couch (as you can see, my ankle is splinted, broke it on New Years Eve day). I had this Haynes manual in a box in my bedroom. It indeed has the wiring diagrams in it. It looks like it's broken down into 77 and 78 model years. I'm not sure if that means that they changed everything from 74-77 and 78 is unique or if they're all different from year to year.

 

[LILCBRA]

Ford Mustang II, 1974-78 (Haynes Repair Manuals) https://a.co/d/5n5I0cC

Used is ~$35 on Amazon if you don't have one. Hopefully it'd be intact. Otherwise your local library might be a good source.

 

[Mcmahst]

It’s probably close enough to figure out the problem. At least Ford usually keeps the same color/marking patterns from year to year. What have you discovered from the disgram?

 

[JackH]

Welcome to the forum!
We want to see pictures of the car too
You have a fuse box below the dash board on the driver side. I would start checking if you can measure voltage their. And if the contacts of the fuses are corroded or if this is a bigger problem.
I think your right, that your ignition is not working of this bigger electrical issue...
Here is a trouble shooting guide for the duraspark if you have voltage at the fuse box:

How to Troubleshoot a 1977 Ford Duraspark ll Ignition System

The Duraspark II ignition system debuted in 1976 with the intent to make substantial increases in secondary voltage and extend system maintenance intervals. Spark plug gaps were widened to take advantage of the heightened current and to prolong spark plug life. Special testers were devised at...

itstillruns.com

The electrical thing at the carb is as far as is understand just for adjustment of the idle speed. No need to mess with it right now.

Hey, thanks for the info. Ill take better pictures of the mustang after i can drive it to a wash. Ill check the fusebox although i replaced all of the fuses already. The link you sent seems like it might help a lot. I'll update tomorrow if anything changes for better or worse.

Thanks,
Jack H

 

[JackH]

Welcome to the group!

The best advice I can give right now is to ensure all connections are clean and are making good contact. Next suggestion is to check different circuits to make sure you're getting power when you're supposed to. A test light is a good start, but a good meter would be better. I used to have wiring diagrams but I don't know if I have them anymore. One of the repair manuals has them although I don't recall which one - I think it was the Haynes manual. I think it would help you quite a bit if you can get your hands on one.

Without knowing much more about your car, there's one situation that I've personally had that could be an issue. I had 2 full sets of harnesses when I put my car back together and ended up mismatching the engine and body harness. It's been probably 20 years now, but iirc it wouldn't turn over with the key. I chased my tail for quite a while til I swapped the engine harnesses and everything worked as it should. I can only assume that that's not what's happening in your case, but it IS something to keep in mind for future reference....

Hello, I appreciate your help! I'll check on everything tomorrow and update if any changes arise. I'll look into buying a repair manual as well. Also, I am stationed in San Diego but I used to live in Marietta and Kennesaw...we might've passed by each other before lol. Also, take care with your injury.

Thanks,
Jack H

 

[LILCBRA]

Hello, I appreciate your help! I'll check on everything tomorrow and update if any changes arise. I'll look into buying a repair manual as well. Also, I am stationed in San Diego but I used to live in Marietta and Kennesaw...we might've passed by each other before lol. Also, take care with your injury.

Thanks,
Jack H

I've only lived here about 10-1/2 years, but it is possible we've passed one another at some point. Went to MCRD San Diego and had MOS training at Coronado NAS in the 90s - good times!

 

[JackH]

Ok, here's a quick update: I looked at the link on troubleshooting a duraspark ignition system and decided to undertake that. I started by checking the distributor pickup coil and found it was nearly fused to the harness. After the coil part crumbled into pieces, I found that the three prongs seem very corroded. According to the article, resistance should be between 790-850 Ohms, mine was a constant 587 which means I have definitely discovered the (hopefully only) problem with the car's ignition. It may take me a little extra time to fix however, because one of the screws just stripped instantly - that was even with PB. I probably won't update again until I fix the listed problems so again I want to thank everyone for the helpful suggestions and the link to that article.

Thanks,
Jack H.

 

[JackH]

Update- I put in the new pick up coil and confirmed a good install by measuring resistance. Still no crank. I have everything working except the starter (lights, side markers, turn signals, hazards, windshield wipers/washer). Could this be a problem with the neutral safety switch? I located it and it doesn't look terrible but I also don't have tail or reverse lights which I have heard are a symptom along with no crank. One more thing is that I tested the starter wire coming from the ignition switch and in the start position, I was getting 4.09 volts. does this wire work on less volts or should it be getting 12 as well? When I jumped the little "S" post that it goes to on the solenoid from the battery, it made the solenoid actuate so I think this ignition switch starter wire may be an additional if not the only problem. Any advice or experiences with this would help.

*Parts replaced are: Solenoid, Battery Cables, Cap + Rotor, Pickup coil, ignition coil, battery, ignition switch, and duraspark module. I'm replacing the solenoid to starter cable tomorrow morning if all goes to plan.

Thanks,
Jack H

 

[2Blue2]

At this point the no crank is the issue, right?
Solenoid jumping will turn engine over, right?

the issue should lie with ignition switch or neutral safety

tested the starter wire coming from the ignition switch and in the start position, I was getting 4.09 volts.

this seems low = high resistance in one or the other?

Did ya try cranking in neutral?
How long has this car sat before your purchase?

*Parts replaced are: Solenoid, Battery Cables, Cap + Rotor, Pickup coil, ignition coil, battery, ignition switch, and duraspark module. I'm replacing the solenoid to starter cable tomorrow morning if all goes to plan.

The only ones for no crank are solenoid and ignition switch

oh and check the engine block to ground strap.

 

[JackH]

At this point the no crank is the issue, right?
Solenoid jumping will turn engine over, right?

the issue should lie with ignition switch or neutral safety


this seems low = high resistance in one or the other?

Did ya try cranking in neutral?
How long has this car sat before your purchase?


The only ones for no crank are solenoid and ignition switch

oh and check the engine block to ground strap.

No crank is my main issue, I've tried cranking in all gears and got nothing. The starter used to turn engine over when jumped from relay but now it seems I burned up the starter cable...
She's been sitting for around 20 years and based on the clues left behind it was serviced at a quick oil change place at 48k miles and parked at 51k in 2003. I guess it would have to be that they threw the neutral safety switch and figured it wasn't worth fixing. I'll try to test it and see if the connector is the culprit or the switch.

 

[Potomus Pete]

Sounds good at 51K. Cant wait to see it. All 78's are good

 

[LILCBRA]

If I understood correctly, you have all of your lights and stuff now? If not, it's possible that the fusible link before the fuse block is fried.... if you have a meter with sharp electrodes you could probe through the wire sheathing on either side of the link to test continuity. I believe the link is located in the harnesss on the driver side somewhere near the brake booster, it's a heavy gage yellow wire and should be pretty easy to figure out what it is once you find it.

As for the NSS circuit, if you've gotten the Haynes manual the NSS is on page 304. I believe you can just jumper the wires at the NSS to disable it. It appears it's a red with light blue wire.

This wire also goes to the Duraspark box and is the trigger wire for the solenoid:

As far as the NSS is concerned, I think the best approach would be to test the trigger wire at the solenoid when you turn the key, then jumper the NSS and test again to see if that is indeed the issue. If it were me and the NSS is the culprit, I'd just leave it disabled.

EDIT: Reread the thread, updated my thoughts....

 

[JackH]

If I understood correctly, you have all of your lights and stuff now? If not, it's possible that the fusible link before the fuse block is fried.... if you have a meter with sharp electrodes you could probe through the wire sheathing on either side of the link to test continuity. I believe the link is located in the harnesss on the driver side somewhere near the brake booster, it's a heavy gage yellow wire and should be pretty easy to figure out what it is once you find it.

As for the NSS circuit, if you've gotten the Haynes manual the NSS is on page 304. I believe you can just jumper the wires at the NSS to disable it. It appears it's a red with light blue wire.

This wire also goes to the Duraspark box and is the trigger wire for the solenoid:

As far as the NSS is concerned, I think the best approach would be to test the trigger wire at the solenoid when you turn the key, then jumper the NSS and test again to see if that is indeed the issue. If it were me and the NSS is the culprit, I'd just leave it disabled.

EDIT: Reread the thread, updated my thoughts....

Yeah I have all my lights and signals and everything. I guess that The NSS is probably the issue then because my solenoid does not actuate when cranking. I can do a little mechanical work but electrical is totally out of my realm of experience and knowledge, when you say jumper the cables do you mean just strip both of them and tie them together? I agree if this does fix the problem just to leave it bypassed because a new switch is like $67 lol.

 

[JackH]

Sounds good at 51K. Cant wait to see it. All 78's are good

I'll post some pictures in the proper forum once I get everything situated with it. Eventually I may start a build thread...just maybe get 2" drop spindles and new suspension components and nice wheels. Appreciate it.