• Hello there guest and Welcome to The #1 Classic Mustang forum!
    To gain full access you must Register. Registration is free and it takes only a few moments to complete.
    Already a member? Login here then!

Won't start after wiring harness replacement LONG

LNimoy

Member
My 1966 basically stock 289 4V coupe suffered a severe underdash wiring harness failure 3 years ago.
2 years ago I purchased a harness from Midlife. (Exceptional man to deal with.)
Due to back and hip issues I was not able to install it until mid July of this year.
I have checked everything under the dash and "believe" everything is hooked up properly.
I went to attempt the initial startup last weekend and encountered a few problems.
#1, The engine did not crank over when the ignition switch was turned to the start position.
#2. The carb was overflowing fuel through the secondary vent tube.
I removed the carb, Holley 80457, removed both bowls and cleaned everything out with carb cleaner.
I adjusted the float level on the secondaries and reinstalled the carb with a new intake manifold gasket.
I replaced the fuel filter. I installed new points, condenser, cap, rotor, plugs and wires.
Battery has a full charge. New battery terminal ends. Engine to chassis ground is good.
I jumped the starter by crossing the battery side of the solenoid to the S terminal.
The car eventually started but was running extremely rough. It back fired through the card once before starting.
It continued to run rough and was around 1500 RPM.s. It would not idle.
I hooked up my timing light (inductive pickup) and the timing was jumping all over, by 20 degrees or so.
I pulled the #1 plug and brought the engine to TDC on the compression stroke and it was on TDC on the balancer with the pointer.
Removed the cap and insured that the rotor was pointing to the #1 plug. Verified the correct timing order and all plug wires are correct.
I put the #1 plug into the wire and held it to the shock tower while turning it over via the solenoid. It had a weak spark.
Also, the brand new plug seemed to be carbon fouled. I cleaned it, but not the others yet.
Reinstalled the plug and started it again. My timing light didn't seem to be firing all the time.
I tried to adjust the timing but it was still all over the place. I couldn't get it within 5 degrees of spec.
I don't know if that is a symptom of my problem, or my timing light is bad. I will be borrowing one from a friend this week.
I hooked up my dwell meter, but the car wouldn't start again. Dwell showed 30 degrees while cranking it over.
I don't know if you can check dwell this way, just cranking, but I did anyway.
After days on the internet, this is my plan in no particular order.
Triple check my underdash wiring.
Check resistance on the PINK wire. (I only have an analog multimeter.)
Check the resistance on my coil for specs .7 to 1.7 OHMs on the primary side and 7,500 to 10,500 on the secondary.
Check voltage at the coil when the key is ON, 6 - 12 volts depending on the points being opened or closed.
I can remove the cap and open and close the points by moving the rotor on and off the distributor lobe..
Check resistance and continuity on the wire from the S post of the solenoid to the distributor.
Check my ignition switch for 12 Volts on the center post with the switch ON. I am sure this is fine as I can jump the Solenoid.
Check ignition switch for proper voltage in ON and START positions using the picture below.
I'll take the wire from the S terminal off the Solenoid and check for 12 Volts in the START position.
Verify that my Neutral Safety Switch is hooked up and test it at my ignition switch. (Anyone know the easiest way to do this?).
Remove and clean all my plugs. Bring to TDC on compression. Verify rotor positioned to #1 wire on cap.
Hook up borrowed timing light and dwell meter. Attempt to start.
Questions.
Have I missed anything?
Will a dwell meter show dwell angle while the engine is just cranking?
Can a carburetor that may not be 100% perfect affect timing that much? ( I am ordering a complete rebuild kit this week).
Any specific wire(s) under the dash that I should look for that would cause no voltage to the S post on the Solenoid?
I've been focusing the ignition switch as the cause of this problem.
Sorry for such a long post.
Thank you for any and all help.

John
 

Attachments

  • Ignition Wiring (1).jpg
    Ignition Wiring (1).jpg
    278.7 KB · Views: 8

B67FSTB

The NorCal dude from Belgium
Seems you know your sh.tt.
One thing comes to my mind.
Did you check ground from battery to chassis. Normally it goes with a thick cable to the engine and with a small cable from the engine to the firewall.
Checking ground cables is the first thing to do.
Operating voltage of the ignition is around 10volts. During starter operation the coil gets it voltage from the s terminal of the starter solenoid. When it runs, the coil gets its voltage from ignition switch through the pink resistor wire. Thereby 10 volts.
TDC and distributor check.
Check if there is no vacuum leak around the carb and intake.
FWIW. B.


Verstuurd vanaf mijn SM-A605FN met Tapatalk
 

LNimoy

Member
Bruno,

Thanks for the compliment, but I really don't know much about the electrical side and only 60 percent on everything else.
That is why I read on here almost daily, but don't post answers to questions..
I'll check the grounds to the chassis again. The one from the head to the firewall is good.
I'll hopefully resolve any vacuum leaks when I rebuild the carb. I do have a new gasket for the carb to manifold installed Friday.
Thank you for the info on the voltage.
I plan to compile a list of things to check if I get responses to my issues.
I have to be careful and plan my work. Every 15 minutes bent over the engine or under the dash requires 15 minutes of back stretching.
Thanks for the reply.
 

Horseplay

I Don't Care. Do you?
Donator
The old service tech in me is trying to read between the lines to flesh out your situation a bit more. Everyone always dives in too deep at first when problems are typically staring you right in the face if you take a few minutes to simply review how things went off course in the beginning. My first question is typically, "What did you do right before it stopped working", whenever someone calls me to help diagnose something. IN your case we know all was good pre-wiring meltdown. Did you ever figure out the cause of that failure? Just age or did something in particular cause that damage that may have hurt what is ailing it now?

Correct to assume the car hasn't seen any attention in terms of getting it running in about three years? Are you dealing with fuel that is of that vintage or did you flush everything? Modern gas isn't great to begin with and left to age, it gets nasty. Could easily explain poor running and such. Your timing light could be what's malfunctioning and you are simply fighting to fire crappy fuel.

I think you are likely on to something suspecting the neutral safety wiring. Easiest explanation for the lack of a key start functioning if you are sure you have everything under-dash connected properly. I don't have a schematic in front of me but should be easy enough to identify the two wires running to it and simply connecting them to bypass it for a quick test.

I'd take another look at the new points. I've heard of all kinds of issues with the quality of such anymore. Bad right out of the box. Breaking upon first minutes of use, etc. That fits a bit with the crazy timing stuff you describe. I can't think of another reason to explain it provided all you state you checked and verified.

Just a few things to consider.
 

Midlife

Well-Known Member
Staff member
Moderator
I'll only comment on the no-start condition. If I were you, I'd focus on that problem first.
I believe you said you get 12V at the unplugged S wire when the key is in CRANK position; is that correct? If correct, and the starter won't crank, you have a bad battery or a bad starter solenoid. If you don't get 12V at the unplugged S wire, your NSS wiring has a break in it somewhere or your NSS switch is not adjusted correctly, or you have a bad ignition switch.
 

LNimoy

Member
Terry,

Thanks for the reply. I agree with you on diving in too deep. The more I read, the more I get confused.
In answer to your questions. Yes, I do know what caused the original harness meltdown.
Two of the clips that held the harness up under the dash broke and the harness was resting on the wiper motor.
The last time I drove the car was the first time I drove it in the rain and used the wipers. (20 years).
The wiper arms scissored through the harness. There is a long thread I posted here 2+ years ago.
I got a new harness from Midlife.

I did siphon the gas out and cranked it over emptying the fuel line at the gas filter before attempting any startup.
I added 5 gallons of fresh fuel and stabilizer before installing the points, plugs etc.
I do believe my timing light may be an issue. It has a plug that goes into a socket on the handle but it doesn't seem to always seat tightly.
I'll be borrowing a known good one on Tuesday. Do you know if you can check the dwell angle while it is cranking over?

I have verified the under hood wiring of the NSS and will check the under dash connector again. I have all the diagrams and
wire numbers and schematics for the car. I struggle understanding then at times. I take them literally.

The points look good, I was concerned about the condenser more than the points. The old points also looked good and were fairly new.

Stumped as to why the Solenoid doesn't engage the starter. (Ignition switch bad?).

When I turn the key, I do hear the voltage regulator engage and disengage when I turn it off.
I found out about that reading in another former on a 10 year old thread.

I have found some info on testing the ignition switch and solenoid. I'll be doing that tomorrow.

Thanks for your reply.

John
 

LNimoy

Member
I'll only comment on the no-start condition. If I were you, I'd focus on that problem first.
I believe you said you get 12V at the unplugged S wire when the key is in CRANK position; is that correct? If correct, and the starter won't crank, you have a bad battery or a bad starter solenoid. If you don't get 12V at the unplugged S wire, your NSS wiring has a break in it somewhere or your NSS switch is not adjusted correctly, or you have a bad ignition switch.
Randy,

Thanks for the reply. I'll take your advice and work on the no-start first.
I have not checked voltage at the S wire unplugged yet. It's now on top of my list for tomorrow.
I believe that my battery is good because when I short battery side to the S side of the solenoid it cranks over fine. quick and steady.
I don't think the NSS is not adjusted. It hasn't been touched and worked fine for 20 years.
I can see the two wires under the hood for it are connected, going to check the under dash wires again tomorrow.
I am going to make up some male/female spade wires about 3 feet long and attach them to my starter switch and the hard plug on the back of it.
This way I can extend it and hold it in my lap while testing it in RUN and CRANK positions.
As for the solenoid, it exhibited this same symptom with the old switch. I replaced it last week with no change.
I realize that the new one may also be bad. I'll focus on the NSS wiring and the solenoid tomorrow.
I believe that the no start problem lies there.

Thank you.
John
 

Midlife

Well-Known Member
Staff member
Moderator
What you might be hearing is the starter solenoid trying to be engaged rather than the voltage regulator. The starter solenoid, if not enough voltage/current is available, will simply click when you turn the key on. I've never heard of anyone hearing the voltage regulator turn on/off, but it is possible.

Just because the NSS switch was working before doesn't mean it is still aligned. Since you have new wiring, make sure your NSS harness is properly attached to the underdash harness inside the passenger compartment. There's a blue/red wire female bullet nearby that can be confused with the red/blue wire.
 

LNimoy

Member
Randy

Thanks. I never heard about the VR clicking either until I ran across a thread on another forum. Since there is no sound from the stater when turning the key to Start. We heard a very slight click near the front driver side fender. If you hold your finger on the cover of the VR you can feel it. Turn the key to Run, and you can feel it again. Something about energizing the alternator before starting.
I will check the NSS adjustment to be sure. If it is out of adjustment, would putting the tranny in N and turning the key to Start "bypass" the switch?
I haven't checked the backup lights yet. If the NSS is good and aligned, they should come on with key in Run position and tranny in R, correct? I am leaning towards under dash wire as that was where the most work was done.
Thanks for the info on the wire colors under the dash.

John
 

LNimoy

Member
What you might be hearing is the starter solenoid trying to be engaged rather than the voltage regulator. The starter solenoid, if not enough voltage/current is available, will simply click when you turn the key on. I've never heard of anyone hearing the voltage regulator turn on/off, but it is possible.

Just because the NSS switch was working before doesn't mean it is still aligned. Since you have new wiring, make sure your NSS harness is properly attached to the underdash harness inside the passenger compartment. There's a blue/red wire female bullet nearby that can be confused with the red/blue wire.
Check this from VMF 2001.

 

Mach1 Driver

Well-Known Member
It doesn't take a lot to get an engine to run. All the basic systems needed are shown below. It sounds like it cranks so you can eliminate the neutral safety switch, solenoid and starter. All you really need is the coil, points, condenser, distributor, plugs and wires. If you jump directly from the battery to the coil as shown in red, you will bypass everything else. Use a screwdriver to jump from the solenoid "S" terminal to the solenoid front battery lug, the car will crank and the engine will start. This is how any self-respecting car thief would hot-wire the car. It applies 12v to the coil and the points/coil won't last forever this way, but it will definitely get the car running.

Forget about the wiring problems and concentrate on the basics. Set the points with a feeler gauge- get it close and it will run. Triple check that you have the plug wires connected correctly. There is a way to roughly set the timing before starting the engine- I'll find that and post it later. I think the problem is the carburetor and fuel. Rebuild the carb. If the fuel is bad and the tank contaminated you can run the car off a small elevated gas container (like an IV drip). You don't even need the fuel pump- plug the line and bypass everything that could cause you problems. Once the engine is running you can figure out the electrical problems- you just don't need that now.
1659352923593.png
 
Last edited:

Mach1 Driver

Well-Known Member
Setting timing BEFORE starting new engine


Method One
by barnett468
On new engines, fill the fuel bowls with gas, and set the timing before starting the engine:

1. First mark the end of the pointer then the damper with white out where you want the timing to be.
2. Remove all the plug wires except for number 1 (so it won’t start).
3. Connect the timing light and jump the solenoid to see where the timing is.
4. With the engine off, rotate the distributor to get the timing closer so you don't have to keep spinning the engine while trying to set it.
5. Once it is set, this is good enough to start the engine. Replace the plug wires.
6. After starting, run the engine up to around 2200 rpm and maintain that rpm for a few minutes.
7. Then rotate the distributor until it makes the most rpm. This reduces the chance that it will get hot during break in.
8. Reset the rpm to around 2200 and let it run for 20 minutes.
9. Reset to correct idle rpm and timing.

Method Two
from video Timing the Ford 289 Engine
1. Disconnect the coil wire from the distributor and ground it.
2. Connect your test light to the coil- distributor lead (points side).
3. Place your engine on the desired BTDC mark on the balancer. Make sure you're on the compression stroke.
4. Connect the test light to battery+. This should turn your test light on BRIGHTLY. If not, rotate the distributor counter-clockwise until the light comes on BRIGHT.
5. Rotate the distributor clockwise until the moment the test light goes DIM. Tighten the distributor hold down. Remove the test light and hook everything back up.
 

Mach1 Driver

Well-Known Member
Once you get the engine running we can tackle the electrical problems. This link will take you to a couple of documents you may find useful. Most people have never seen an actual Schematic, because Ford never released any- all they publish are Wire Diagrams. If you don't have a good wire diagram, get one- a Ford authorized and verified wire diagram. I used the free one on Average Joe Restorations (it's an Osborne copy). I backward engineered from the wire diagram to the schematic. Engineers start with the schematic and make the wire diagram from that. The schematic simplifies each circuit and shows the internal switching of components so you can see at a glance how it works. It doesn't usually show wire colors, plugs and other trivia- you still need the wire diagram to wire the car.
 
Last edited:

LNimoy

Member
UPDATE:

Thank you all for the replies.
I spent time Sunday and Monday checking whatever I could that did not require an extra set of hands.
Bench test coil - within specs.
Check voltage at ignition switch - uh oh.
In response to Midlife, quadruple checked the underdash wiring. Specifically a red/blue and blue/red wire being very close to each other.
Bam - NSS plugged into wrong wire. Ignition switch now cranks engine over.
Now, why is the car not starting.
A friend comes over today with his timing light. It exhibits the same symptoms as mine. Timing all over the place while cranking.
I went over everything that I did, he verified everything and pondered for a moment.
Removed a plug and tested the spark while cranking. Weak spark. Too weak he said. Get a new coil.
Put in the new coil (what a chore that was), car starts right up. Check dwell, check timing, all good.
As a bonus, my timing light is good. The coil was not "HOT" enough to fire either timing light. So much for the bench testing.
Engine purrrs. Starts instantly. Smooth as silk.
Moral: Keep It Simple Stupid.
I got lost on looking at all the problems. Focus on one.
All the replies put me in position for a quick resolution when a new timing light came into play.
I assumed my old light was bad. I thought ignition switch was bad.
Focus on one issue when you have multiple.
Checked all my lights. Seems I may have missed the B/U light connection.
Need to wait for my son to crawl up under the dashboard.
Thank you all again.

John
 
Last edited:

Midlife

Well-Known Member
Staff member
Moderator
Check voltage at ignition switch - uh oh.
In response to Midlife, quadruple checked the underdash wiring. Specifically a red/blue and blue/red wire being very close to each other.
Bam - NSS plugged into wrong wire. Ignition switch now cranks engine over.
Well, the more I thought of this, the stranger it became at least for a 1966. There are 2 female plugs in this area: a red/blue for NSS and a blue/red for PRNDL lamp (fused hot when key is in ACC or run). If you plugged the NSS input line into the PRDNL bullet, and if the tranny was in P or N, then the starter would crank whenever the key was in ACC or RUN. Since you don't describe this condition, either the tranny NSS switch was not in Park/Neutral or the fuse for the heater and PRNDL lamp has blown.
Does your heater motor still work?

There are two other female plugs in that area: a black/blue wired one and a green/yellow one. If you plugged in your male bullet of the NSS input line into the green/yellow one, the starter would immediately crank (that line is fused BATT hot). If plugged into the black/blue female bullet, the starter would crank whenever the doors opened.

For a 1965, the PRDNL lead is controlled by dash lamp power. Your starter would crank whenever you pulled the headlight switch out, regardless of key position.

You also mention that the backup lights aren't working. That also suggests a misaligned NSS switch or a blown ACC fuse.
 
Last edited:

LNimoy

Member
Well, the more I thought of this, the stranger it became at least for a 1966. There are 2 female plugs in this area: a red/blue for NSS and a blue/red for PRNDL lamp (fused hot when key is in ACC or run). If you plugged the NSS input line into the PRDNL bullet, and if the tranny was in P or N, then the starter would crank whenever the key was in ACC or RUN. Since you don't describe this condition, either the tranny NSS switch was not in Park/Neutral or the fuse for the heater and PRNDL lamp has blown.
Does your heater motor still work?

There are two other female plugs in that area: a black/blue wired one and a green/yellow one. If you plugged in your male bullet of the NSS input line into the green/yellow one, the starter would immediately crank (that line is fused BATT hot). If plugged into the black/blue female bullet, the starter would crank whenever the doors opened.

For a 1965, the PRDNL lead is controlled by dash lamp power. Your starter would crank whenever you pulled the headlight switch out, regardless of key position.

You also mention that the backup lights aren't working. That also suggests a misaligned NSS switch or a blown ACC fuse.
Randy,

Thanks for the reply. I probably used the wrong words when describing what I found.

Because of my back issues, I can't lie down under the dash for any period of time. I had to wait until my son was available to assist me. I had him checking the connections as I was reading them off to him. In a previous response you alerted me to the fact that there was a red/blue plug in close proximity to the blue/red plug up under the dash.

When checking all the plugs, I was calling out the connections to him and he would check them. The PRNDL (blue/red) was hooked up to the proper wire. Sometime later, when I called out the red/blue for the NSS, he verified it, but he was actually looking at the blue/red for the PRNDL again.

When you mentioned the other wire in proximity, I had him dig back up in there looking for it. He found it and the corresponding plug, plugged it in and the backup lights came on when tested.

The PRNDL light is also functioning properly.

Without your response mentioning that, I don't know how much longer it would have taken me to find it.

Thank you,
John
 
Top