'68 Will Not Start - No Lights, Not Cranking

[68Blue302Coupe]

Good afternoon all,

I was hoping someone had some advice on some electrical issues my '68 is having. I realize diagnosing anything electrical at a distance is tough, but I would appreciate any suggestions or tips.

I am wrapping up part one of a multi-year restoration project on my '68 coupe. The car was an I6 with a C4 transmission, and I have replaced that with a 302 and a 4 speed top loader along with a 8" rear, disc brakes, seats from a '99, new wheels, and extensive sheet metal work to replace rusted floors and front frame rails.

I just finished the last steps installing the 302 and tried to fire it up yesterday but got nothing. I was not terribly surprised since I had to basically disassemble most of the car for the metal work and engine / trans conversion.

Here is what is going on:

- No headlights, dash lights, turn signals, or cranking. No noise coming from the starter solenoid. Just nothing.

- My dome light and wind shield wipers do work... strangely.

What I have done so far:

- Charged battery, but it has been sitting for about 6-7 years, although was pretty new and had almost no miles when I parked the car and started the restoration.

- Cleaned the terminals on the starter solenoid and the cable ends running to it. Used some light sand paper and steel wool to remove any dirt. Solenoid was replaced about 10 years ago and has fairly low miles.

- Cleaned the terminals on the volt. regulator and the cable ends running to it. Sanded back the mounting surface on the engine bay to that it had clean metal to ground to.

- Checked fuses and non are broken, but the fuse box terminals (where the fuses go) looks pretty rusty.

- Checked that the headlight harness is connected (it is). Those wires look pretty rough though....

- All battery and ground cables are new. I have the battery grounding at the engine block, and the engine-firewall ground connected to the back of the head. I sanded away the paint on the block where the cables connect, but should probably check that again.

- Using a test light, I have power at both terminals on the coil. Is this normal? Also have power at the positive side of the solenoid.

Complicating matters, I have an old Jacobs electronic ignition system on the car, and a newly installed Pertronix Ignitor in the distributor. I **think** I have this hooked up correctly, but it was a little guess work. The Jacobs system is grounded properly, from what I can tell. The Jacbos worked fine about 7 years ago....

I also just replaced the firewall insulation and have to unbolt the fuse box from the firewall. Could I have done anything then that would cause this? Does the fuse box ground to the firewall (i.e. need some kind of metal/metal contact like the voltage regulator)?

I am not really experienced with the electrics on these cars, and I don't own (or know how to use) a volt meter. I do have a test light. Does anyone have any advice on how to diagnose this problem? I'm flying blind right now.

Thank you for any help!!

 

[68Blue302Coupe]

I just read something about a neutral start switch on cars that were automatics. When I did the conversion, I removed the auto shifter (of course). Should the wiring for this switch be grounded or something? Could that be causing my problems?

 

[hungrymonkey]

neutral safety switch will cause the car not to start. But the headlights have me thinking there is either a bad ground connection or bad fuse/frangible link.

 

[hungrymonkey]

this is how I bypassed the neutral safety switch on my 67. Should be similiar to a 68. Worth a try to see if it will crank.

 

[68Blue302Coupe]

Update:

I'll try that nuetral safety bypass next, thanks for the photos!

I just came back from the auto parts store, and the battery was indeed bad, was not holding a charge. I replaced the battery but same result, would still not crank. I also tried bridging the positive battery cable and the first terminal on the solendoid and it did crank over. So I can probably eliminate at least the starter and battery from my list, and maybe the solenoid (right?).

I think the problem could be somewhere in the mess of the Jacobs and Pertronix systems. Does anyone know if I can bypass the Jacobs computer / ignition controller, and just hook up the pertronix directly to the (separate) Jacobs coil. I was thinking that I could try to use it as a regular coil, eliminating the ignition controler as a variable. If it fires, then its the controler causing the problem? The Jacobs coil is simillar to other high output coils, has a positive and negative terminal, and also has a ground wire.

 

[hungrymonkey]

If the starter is not turning over the engine, and the headlights are still not functioning. I will bet that its not the coil causing the problems.

Try bypassing the solenoid with a screw driver and see if it cranks. Also, recheck the ground from the battery to the block. Make sure it has a solid connection.

 

[68Blue302Coupe]

Hi,

Thanks for helping me with this. I did bypass the solenoid terminals with a screwdriver and it did crank over. So I was thinking that, since I got it to crank that way, I could eliminate the solenoid and starter from my suspect list.

I'll check the grounds again. There's the one from the battery to the engine bock, the one from the block to the firewall--any other major grounds I should check?

 

[hungrymonkey]

Those are the ones that will cause your problems.

you might want to see if the power wire to the ignition switch is hooked to the solenoid and is providing power at the switch.

you should be getting constant power to the switch.

 

[68Blue302Coupe]

Update:

Jumping that neutral safety switch had some impact. Now I get a single, loud click from the starter solenoid when I turn the key, but the engine will not crank. My lights are working now, too, so there is progress.

I tried bridging the battery cable / starter solenoid and now the engine will not crank, just gives me that single loud click from the solenoid. Maybe I fried it when I bridged the battery cable / terminal?

I also manually turned the crank, just to make sure the engine could turn, and it was fine.

 

[68Blue302Coupe]

You might want to see if the power wire to the ignition switch is hooked to the solenoid and is providing power at the switch. You should be getting constant power to the switch.

I am not sure I follow--is this one of the wires that connect at the "I" or "S" threaded terminal?

 

[hungrymonkey]

There should be a wire leading from the + side of the solenoid, or + on the battery going to the ignition switch. Then from the ignition switch to the solenoid.

here is a diagram of a 66. Which is fairly similiar.

http://www.allfordmustangs.com/foru...questions-starter-ignition-68-66ignit_web.jpg


here is a downloadable diagram for a 68.

http://www.fourchisholms.com/mustangs/obj/68mwd.zip


The diagram for the 66 is a bit easier to read than the 68 one. You should have constant power to one side of the ignition switch. put your test light on it and see.

 

[hungrymonkey]

Update:


I tried bridging the battery cable / starter solenoid and now the engine will not crank, just gives me that single loud click from the solenoid. Maybe I fried it when I bridged the battery cable / terminal?

.

From my experience, this is almost always due to a poor connection from the big leads off of the battery. Usually it is the ground wire that is the culprit. Either from corrosion or a sketchy connection.

There is enough to take the load of the lights, but as soon as you use the starter it fails.

fwiw, I have only fried solenoids with the circuit closed. It will constantly click and eventually start smoking.

 

[68Blue302Coupe]

I read something about the starter grounding out on the headers and suspect this may be the problem. All the battery cables are new, I'm getting power to the ignition wire on the solenoid, and I replaced the solenoid yesterday just for good measure.

I went to remove the starter yesterday to inspect it and noticed that it was touching the headers. It looked like the post where the ground wire attaches was also touching the header (which is uncoated/unpainted). Would this cause the starter to not turn, i.e. "ground out"? I am not familliar with this, as I assumed that the starter was ground to the engine anyways. If so, is there any way to wrap some insulation around the header or am I looking at needing a mini-starter?

 

[hungrymonkey]

stick something non conductive between that and the header. See if it changes anything.

If it is making contact, it will eventually eat through any type of wrap you put on there. either way it needs to be fixed before the starter or the headers get ruined. You can hillbilly fix it with a BFH, or get a mini starter.

 

[68Blue302Coupe]

Got it started last night! The threaded starter cable terminal was in contact with the headers and was grounding out the starter. I cut 1/2 of the terminal off (still plenty left to hold the battery neg. cable) and reinstalled. The starter overall clears the Tri-Ys by about 1/2 an inch max, but its not touching now. Still, I'm going to look for a mini starter soon and or wrap the headers. First time starting the engine in 6 years!!!

 

[hungrymonkey]

working on a cooked engine bay with that. Glad you figured out the problem.

 

[stonecoldtx]

Got it started last night! The threaded starter cable terminal was in contact with the headers and was grounding out the starter. I cut 1/2 of the terminal off (still plenty left to hold the battery neg. cable) and reinstalled. The starter overall clears the Tri-Ys by about 1/2 an inch max, but its not touching now. Still, I'm going to look for a mini starter soon and or wrap the headers. First time starting the engine in 6 years!!!

It is possible that you have a misconception of what cables are positive and negative.

For the record, the positive side goes to the solenoid on the fender apron, and the negative side goes to the engine block.

The cable that goes from the solenoid to the starter is ALSO a positive cable (not a negative cable), but is only active when the starter solenoid is engaged, and provides a direct voltage flow from the battery to the starter at that time.