70 fastback: Good battery, but nothing happens.

hankmeister · Mar 4, 2024

1970 351C, 4 speed.
Was a random occurrence previously. I could be rolling up to a stop light, put in the clutch, and it'd die. But then after a few seconds, it'd start again. Or I'd be driving along, and all of a sudden the alternator gauge would bury out to the positive. But now the car does nothing when I attempt to start. No starter engage/crank, no solenoid click, nothing. AFAIK there is no clutch/neutral safety switch, and I've owned the car 40+ years.

The battery is new/good. When I open the door, turn on the lights, turn the key to "start" position, basically engage anything electric, the alternator gauge bottoms out to the negative side. Haven't tried jumping the solenoid yet to see if it cranks then. Have had some other issues, such as my horn & hazard lights blew a fuse, so I think I may have a short somewhere in the steering column. (When I replaced the fuse, the flashers worked - but when I wiggled the steering wheel into the "lock" position, it blew the fuse again). The last time I drove the car - about 4 weeks ago - it happened but restarted, but the alternator gauge bottomed out on the high side (charging) for the entire drive.

Any thoughts greatly appreciated.

Hank

Noobz347 · Mar 4, 2024

It sounds like the ignition switch. From what I've seen so far, they're a pain to get hold of for a '70.

AeroCoupe · Mar 5, 2024

DC has them stock.

Ignition Switch Housing for 1968-70 Ford Trucks and Cars | Dennis Carpenter Ford Restorations

Ignition Switch Housing Ford Trucks Cars 1968 1969 1970 Thunderbird Maverick Econoline Falcon Fairlane D1AZ11572C

www.dennis-carpenter.com

I believe 1971 is when they changed from the dash mounted switch to the column mounted switch.

70mstang · Mar 7, 2024

I'd pull the steering wheel off and examine everything inside of the column for dirty or burned connections. I think there were just 2 or 3 short screws holding most of the electronics in there, this connector is a good place to look too.

manicmechanic007 · Mar 9, 2024

Check your fuse links by the starter relay
That power to the ignition switch comes from there
If your alternator pegged you may have burnt a fuse link
Are you still running an old-points style regulator for your alternator?

Mcmahst · Mar 10, 2024

Well, on a 70, there are three electrical things going on in the steering column. Horn, emergency flashers, and turn signal. Both the horn and emergency flashers use direct battery power (there on all the time) and any short in those could result in a dead battery. I would start there, pulling the steering wheel and examine the turn signal/emergency flasher switch. You can also see if the horn copper buttons are in place. Usually when those go bad, you get an audio signal. I would also check to see if the voltage regulator is bad, especially if you have an original pints style version. Here is a simple Reg test process I stole from Bigb427 @ VMF:

1) engine off, test battery voltage.
2) engine running at 1500 - 2000RPM battery voltage should be at least 1 volt higher than step 1, but not higher than 14.7 volts.
3) If step 2 is ok, then look for a drain on your battery, or the battery itself might be deffective
4) If step 2 is lower than you have a bad alternator or regulator. If step 2 is higher than 14.7 you have a bad regulator
5) If step 2 was lower full field the alternator by jumping the "A" & "F" terminals in the wire harness that plugs into the voltage regualtor. See pic: http://thelincolnmarkviiclub.org/Gallery/albums/album92/VR_illistrated.sized.jpg The markings "A" & "F" might be different. This is ok, the position is what is important.
6) If full field voltage tested at battery is still not at least 1 volt higher than step 1 alternator is bad. If it is now more than 1 volt higher regulator is bad.
Things to add: unplugging the regulator with the engine running will not harm anything other than discharging the battery.
Disconnecting the battery with the engine running may indeed harm the alternator - do not do this.

Let us know what you find and good luck.

hankmeister · Mar 12, 2024

Noobz347 said:
It sounds like the ignition switch. From what I've seen so far, they're a pain to get hold of for a '70.

Thanks Noobz - one of the avenues I'd planned on trying. Hoping to give an update as things progress!

best
H

hankmeister · Mar 12, 2024

70mstang said:
I'd pull the steering wheel off and examine everything inside of the column for dirty or burned connections. I think there were just 2 or 3 short screws holding most of the electronics in there, this connector is a good place to look too.

Had the steering wheel off to swap out the turn signal / emer flash assembly (turn signals worked, flashers didn't, turn sig stalk wouldn't "snap out" after the turn). Everything seemed to look ok, but could only see so much.... And other than the turn signal stalk returning to center after the swap, no other change.

best
H

hankmeister · Mar 12, 2024

manicmechanic007 said:
Check your fuse links by the starter relay
That power to the ignition switch comes from there
If your alternator pegged you may have burnt a fuse link
Are you still running an old-points style regulator for your alternator?

Everything under the hood looks okay, but we're dealing with a 55 year old harness (give or take), so something under wrap might be wonky.

I replaced the volt regulator with a Marti repo that I ordered a while back and just hadn't installed yet. The old regulator cover popped off in my hand upon removal, so I'm pretty sure some moisture got in and caused some corrosion. Got her started and driven after the swap, seemed to cure the high/low pegging of the alternator gauge.

best
H

hankmeister · Mar 12, 2024

Mcmahst said:
Well, on a 70, there are three electrical things going on in the steering column. Horn, emergency flashers, and turn signal. Both the horn and emergency flashers use direct battery power (there on all the time) and any short in those could result in a dead battery. I would start there, pulling the steering wheel and examine the turn signal/emergency flasher switch. You can also see if the horn copper buttons are in place. Usually when those go bad, you get an audio signal. I would also check to see if the voltage regulator is bad, especially if you have an original pints style version. Here is a simple Reg test process I stole from Bigb427 @ VMF:

1) engine off, test battery voltage.
2) engine running at 1500 - 2000RPM battery voltage should be at least 1 volt higher than step 1, but not higher than 14.7 volts.
3) If step 2 is ok, then look for a drain on your battery, or the battery itself might be deffective
4) If step 2 is lower than you have a bad alternator or regulator. If step 2 is higher than 14.7 you have a bad regulator
5) If step 2 was lower full field the alternator by jumping the "A" & "F" terminals in the wire harness that plugs into the voltage regualtor. See pic: http://thelincolnmarkviiclub.org/Gallery/albums/album92/VR_illistrated.sized.jpg The markings "A" & "F" might be different. This is ok, the position is what is important.
6) If full field voltage tested at battery is still not at least 1 volt higher than step 1 alternator is bad. If it is now more than 1 volt higher regulator is bad.
Things to add: unplugging the regulator with the engine running will not harm anything other than discharging the battery.
Disconnecting the battery with the engine running may indeed harm the alternator - do not do this.

Let us know what you find and good luck.

Swapped out the regulator, that seemed to fix the pegging issue.

There's no horn/flashers at all, so somewhere in that harness there's a short. I did swap out the appropriate fuse for them, and they worked until I wiggled the steering wheel into lock position, which blew the fuse again. (As mentioned in original post) So I'm hoping/thinking as mentioned above the ignition switch (age unknown, but not the original) has reached it's effective lifespan, and swapping that out will remedy things. If not, then it's the dreadful task of tracing wires from A to B to C, and finding the short.

MANY thanks to all for tips & suggestions. Greatly appreciated!

H

Mcmahst · Mar 13, 2024

I wonder if the power to the horn button is grounding out on the column. Those two little copper, spring loaded buttons, can come out of their holders and arc as you pull the wiring. That might explain your issue. You might pull the steering wheel, replace the fuse, wait until dark, pull the wiring, and see if you can see arcing in that area. Just an idea to explore.

manicmechanic007 · Mar 14, 2024

Are you are still fighting this issue of "got nothing" after the amp gauge pegged?

hankmeister · Mar 21, 2024

manicmechanic007 said:
Are you are still fighting this issue of "got nothing" after the amp gauge pegged?

Didn't happen on last drive after changing the regulator (2 weeks ago or so) but it was intermittent anyways. One drive yes, 2 or 3 more drives no, then would happen randomly again.

H

70 fastback: Good battery, but nothing happens.

hankmeister

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