Hey guys I have been trying to track down a low voltage or maybe amperage situation to the S terminal on my starter solenoid. When I turn the key to the start position it gets about 9 volts but it starts out low and climbs to that over a few seconds. The solenoid wont kick in and barley even makes a click just a slight kind of ping sound. If I cross the battery lead to the S term. it kicks

how do these diagrams overlay? how do I follow a wire through the fuse box?

Does the red wire feed power through the ignition switch to the purple S terminal wire? Or does the switch simply close to complete the circuit?

Do these two halves overlay or are the both one side of the fusebox?

Is the power fed from the red wire to the orange wire and across a fuse to the Purple S terminal circuit here? Or does it go to the horn relay first? If so what route does it take?
solid every time. I know all the power to the car comes to the solenoid first through the Bat. cable. Then travels on the red wire that is on the same large solenoid terminal to the fuse box and to the horn relay. OK Can someone here tell me
1) Does power go through the fuse box to the ignition switch?
2) Does power go to the horn relay first then to the fuse box, then through the ignition switch?
I can follow the schematic fairly easily until I get to the fuse box. how do these diagrams coincide? is each picture one half of the fuse panel? How can I follow a wire through?
I have seen similar threads but none can tell me the exact route of power from the solenoid through the primary starting circuit on the purple wire back to the S terminal.
3) does the purple wire get fed from the ignition switch? if so what color feeds it?I am including some pics and a little coloring project. As you can see I have lots of questions and I have been racking my week brain over this. Maybe someone can help me connect the dots here. Much appreciated. By the way my wiring harness is only a couple years old and it a lectric limited accurate repro and matches the schematic. I'm sure some of you guys know this like the back of your hand and many confused forum members could benefit greatly from this info.
Thanks reading this far and of course any info and or discussion is alway much appreciated. Thanks 69roadster

 

There should be a solid 12 vdc going to the starter solenoid and then being transferred to the starter via its power stud. If the starter is not getting full 'juice', the positive battery cable is definitely suspect....but the ground cable from the right front frame over to the right motor mount bolt and then to the starter housing needs to be intact also. If the ground wire is bad, not enough current can pass thru to the starter (due to added resistance in the cable/connections) and voltage will read low.

Make sure these cables are in good condition EXTERNALLY and INTERNALLY. You need to peel back the insulation at the end terminals to be certain the wire has integrity as well as the terminal and the connections.

 

Thanks 7t1 vette. I have new pos. battery cable. Starter works fine when I cross the large terminal to the S terminal. Low power at purple S wire even tried grounding directly to battery neg. With jumper cable. Problem is somewhere in the primary side. Secondary all good.😉

 

You didn't mention anything about the main grounding cable between frame and right motor mount...OR whether that same motor mount bolt retained the front starter mount that is the path by which the starter connects to electrical ground.

 

The power comes from a fusible link to the ignition switch- I'd check power there first(see below)


Then I'd look at the neutral (auto) or clutch safety switch as next the culprit.




Clutch safety switch and wiring-

 

7T1Vette, funny you mention that ground. It is all there including the starter brace. However, I did not replace it along with the battery cables. I probably should just to make sure everything is updated.

 

OK Richard 454, Thank you for that little bit there. I have bypassed that clutch safety switch to try and troubleshoot that. I have the column out now waiting on a new ignition switch. in the mean time while its out I can trace out the circuits and see if maybe that fusible link is going. Thanks again a couple of key answers here. No pun intended. Gonna get back to work on it over the weekend. good stuff ,thanks again.

 

You are changing the ignition switch, at the bottom of the column, not the key switch, right?

Basic schematic:

 

Yep, Have new switch coming from lectric.

 

Peterbuilt, I like this little diagram. Its nice and simple. I was wondering if where the purple wire passes through the firewall is through the fuse box? Also does the ignition fuse actually protect the ignition circuit or is it there just for accessories. I guess I'm gonna get out there and do some continuity checking today. What I want to do is load the circuit and check for voltage drop. Just gotta figure out what wires it is first right. I am narrowing it down.

 

Yes- he purple wire goes through the firewall at the bulkhead connector behind the fusebox-

Looking into the passenger cabin from the engine side- purple wire comes through on the top left side

 

Just replace that main engine grounding wire while you are waiting for other parts. If that cable is original to the factory build, it likely NEEDS replacement anyway. Forty-plus years of service in that environment will age any copper conductor significantly. Give that poor starter a break!!

 

The C2 cars had service bulletin to address the ignition switch contacts degrading and dropping voltage to the starter solenoid and failing to start. The fix was a second solenoid which gets activated by the degrading ignition switch and applies full battery voltage to the starter solenoid. It doesn't replace the starter solenoid but ensures it gets full voltage to operate the starter solenoid and kick out the bendix gear. I don't know if that service bulletin applies to a '69 car.

My guess it's easier to install an extra solenoid then to replace that switch inside the steering column.

 

THEN IT WILL BE LIKE A FORD !!!

 

Haha, right. I am trying to keep or return the car to original. That is however a good fix for the situation. Well after some trial and more error. With help from the diagrams sent by Richard 454 I was able to trace the primary starting circuit out. 71 definitely different than 69. I got out my old harness and figured it all out. Well Also managed to break the pot metal track inside the column from twisting too hard on the key. So, I broke down the column to replace the little rack. This took some time. But I noticed that when I pulled on the ignition switch actuator rod the starter would crank perfectly every time! This lends credence to Cardo0's post. The more I pulled the more juice I got on the meter. Maybe that little rack was already failing or maybe the ignition switch is wearing out or both. The switch is original. Either way they are both getting replaced. Also ordered the ground cable to the motor mount and other ground straps. OK once again waiting on parts. Thanks again for all your input it definitely helps me to keep my diagnosis on the rails

 

FYI there are some really good YouTube videos for the C3 ignition switch replacement. And some not so good videos of this but it's worth the time it takes to sort out the best and the worst. I liked the one by Astrial Auto Repairs the best.

Well the difference between a chevy ignition switch added solenoid and a Ford starter solenoid is the Ford actually moves the bendix gear where the Chevy added solenoid only boosts the voltage to full battery voltage to the starter solenoid which now doesn't see a voltage drop across the ignition switch contacts. Yes I can't stand it when others install an additional solenoid when they have an hot soak problem or an actual bad solenoid/starter. You can read posts by some bozos that can't even explain how to wire a added solenoid but swear it works because that's what Ford uses.

 

Yea, I have seen some of those vids where they add one in and call it "The fix". Well I've got my column out already and taken apart so I might as well replace the switch. Also having my original wiring harness has helped me a lot with finding witch wires go where. This problem has bee n getting gradually worse. Parts will arrive next week. I will update on what happens. Thanks again for your help.

 

Well Gents, I finally got all the parts and the time to get things back together. After all is said and done, my suspicion is that the ignition switch was worn and slowly losing contact in the start position. After pulling out and tearing down the column to replace the switch and the broken ignition rack. everything works just fine. This was not easy but I had no choice. Also learned alot about how this ignition system works. Thanks again for all you input and advice.

 

Thx for the follow up. Its nice to hear how things worked out.