Short Circuit During Key Accessory Position

John,

The collective here would like to have more information, please.

1.  How did you determine that there was (is) a high current draw?  Did you use a DC ammeter (clamp type or other) to determine the load?

2.  Have you tried removing Fuse #10 to see if the high current draw stops? Unless someone has made modifications,  Fuse #10 controls all of the accessory loads, which are the headlight door motor, heater / AC fan, and the AC temp switch.

Note that the accessory circuit is also energized when the ignition key is in the run position.  

John

Have you checked the grounds for continuity? 1. under the dash and 2. the ground strap body to ZF / engine.

...Before the Starter MOTOR, There is the Starter SOLINOID, Energized by the RED? wire from the Start Position of the Starter Switch. Could this be 'Chaffing' to Ground...or Just Shorted Internally?? 'Some' cars have a 'By-pass' (of the Ballast Resister) That provides +12 Volts, from the 'Activated/Energized' Post on the Solenoid, to the + Side of the Coil...ONLY upon Starting!

Good-Luck!

MJ

Thanks for all the info here.

I determined the high current draw by measuring the voltage on the firewall solenoid +12V switch terminal.  It dropped to 7Vdc when switched while the main battery was at 12.9Vdc. 

I haven't pulled Fuse #10 but will try that today and report back.

I'm using the MSD ready to run distributor and coil, so the ballast resistor is eliminated.  I do have the pink wire from the old ballast resistor connected to the (+) side of the coil.  Maybe this is one issue?  However, when the car does start 50% of the time it appears to be running just fine.

I also replaced the OE firewall solenoid with one from the local auto parts store.  I could reinstall the OE Solenoid and see if that changes anything.

I should have mentioned I have the dash out since I'm updating the entire car where I can.  I have check the ZF Ground Strap and that is good but I'm not sure where the dash ground strap is and I bet that is not connected since I pulled everything out during the original tear down.

Any ideas on where the dash ground strap would be?

Thanks,

John

Way up under the dash (or where the dash would be) on the driver side. Its the other side of the ground post in the front trunk.

The harness ground stud is actually closer to the drivers side cowl drain tube , behind the tach.

The battery ground post is just a bolt welded to the body by the heater box.

I know the front truck ground lug is good on the trunk side but haven't checked the inside by the heater box.  I bet the ground harness isn't connected on the dash side since everything was apart for the rebuild.

I will check it out.

Thanks,

John

I check the dash ground and it is good and tight, I never removed it doing disassembly of the dash.

I removed the starter solenoid wire from the firewall solenoid and everything worked as it should.  When I connect it back up to the solenoid the battery drops to 3V when cranking.  So I either have a bad battery or my new DB Electrical starter must be bound up on the flywheel.  I did install a 0.100" shim to see if that would help but the same results.

I will have the battery tested tomorrow and go from there.  If the battery is good then I still don't have the starter positioned correctly.

The first two gear reduction starters burnt up because they were till engaged when the engine was running during cam break in.

Any thoughts on the starter?

Thanks,

John

...I was once sold the Wrong starter motor for My 351 Cleveland. It tore itself apart. It turned out it was for a 351 Cleaveland with a AUTOMATIC Transmission (Flex-Plate). I had NO Clue! I was in Las Vegas when the starter burned out. 'It' would Start and Got Me Home...but disintegrated the Nose Piece! LOOK at It VERY carefully and Compare with a known Correct Starter! It's all about the Bendix/Gear Position and Length of Throw.

Because the Position of the (Automatic Trans) Flex-Plate Ring-Gear is CLOSER to the Starter Drive Gear...than it is on the 'Correct' FLYWHEEL, the Gear and Bendix, Never did Completely Disengage!!! Sounds like Your Problem. I did Not discover the discrepancy until I was back Home and replaced the starter!

Again...Good-Luck

MJ

Sounds like you have an inherent clearance issue between starter and flywheel. You do have the correct short nose starter #3223 for the manual 164 tooth flywheel? (the 157 tooth version is longer snout). Although not associated with the clearance, the PMGR starter also requires some wiring modification.

I will pull the starter again today and compare to my stock core that I kept.  The DB Electric starter is the one that was recommended by many on this forum so I believe it to be correct but will double check.

I do have the wiring connected the same as Joules' diagram above.

Thanks,

John

I was going to offer a word of caution about the starter possibly staying engaged. Reading further I can see you are familiar with that workflow!

BTW an engaged starter sure sounds a lot like an exhaust leak at idle. A buddy successfully convinced me that's what mine was. Potentially your key is staying stuck in the start position? Or the starter is wired up incorrectly. Or it's the wrong part and does not fit.

Good luck

Good point on the key possibly being stuck. I will be sure check that as well.

Thanks,

John

I removed the starter again and left it connected as it would be in the car.  I used jumper cable to ground the starter to the car chassis.

Also had the auto parts store confirm my battery was good.

Starter spun over with no issues at all while lying on the ground.   So, I added another shim and installed the starter again.  It turned over fine for 5 or 6 tries.  I will try it some more today to see if the issue is solved.

At this point I have 2 shims for a total of 0.200" of spacing on the DB Electric starter.  I did compare it to my original Motorcraft starter and there is about 0.100 of difference when the Bendix gear is fully extended.  The DB Bendix does extend slightly further than my OE version.

Hopefully this my issue and I can move on to the next gremlin.

Thanks,
John

#2551

Hi John,

Yes, the engine does have the spacer installed between the engine and bell housing.  I'm going to try turning the engine over more this evening and see if the starter shims have solved it.

Thanks,
John

why not go to your local parts store and buy a rebuilt ford starter for $50 and install it.  There is something fundamentally wrong with the concept of shimming the DB starter.  If you search this forum, there are multiple threads on installing the DB successfully and no shims were needed.  You either have the wrong starter or something else is not correct.

Ok, seems I've been chasing the rabbit down the wrong hole.  I've confirmed the issues is not my starter and have figured out how to reset the problem when it happens.

1. The first time the problem happens it is always in the "Start" position.

2.  Turn the key off and back to the "Run" position all the dash light are out and the 12V switch is at 7Vdc.  All power is dead and when turning the key to the "Start" position, nothing happens, dead silence.

3.  Unhook the battery and everything is back to normal, engine turns over and starts just fine.

I'm starting to wonder if the key switch may have a short to ground or maybe there is a bad relay in the system?

Last time this happened I pulled Fuse #10 but nothing changed and all 12V switched power was dead.

Any thoughts?

Thanks,

John

John,

Are you still using the Veglia ammeter?  If so, that may be the source of your problem.  They are notorious for having loose connection problems.  

John

a simple test to eliminate that as the problem is disconnect both leads from the ammeter and simply bolt them together.  Make sure you cover them with rubber as they not ground out.  

I did reinstall the ammeter.  Now that you mention it, I didn't have this issue when I had it bypassed, connected and insulated like panterapatt mentioned above.

I will bypass it again and see if the issue goes away.

The plan is to run a volt meter that I have from Hall Pantera, just haven't got that far yet.

Thanks,

John

It  may be in your well used 52-yr old ignition switch. Pantera ignition switches are in 2 parts- the electrical section and a separate part for the mechanical . You can work on or replace either separately if necessary.

I have a short too. Mine is in run and on fuse 10. I pulled everything apart and can't find it. Answering BW's caution, the ignition switch is new and was eliminated as the issue.

I have added accessories to the car and have not eliminated the possibility that I just have more then 30 amps on that fuse now.

I share your frustration. This is a tough one to diagnose. The obvious answers aren't working. There should be another circuit that handles the accessories in the run position.

Good Morning, I'm back at it again after the car starting flawlessly many times last weekend.  Went to start it yesterday and 12V drops to 6V in the Run position and engine won't crank.  Basically, get a single-clicking sound like the solenoid is stuck.

I removed the key switch cover and used a multi meter to confirm the key switch is working and there are no shorts to ground.  Key switch seems to function in all positions as it should.

However, I separated the harness above the steering column because I found that the two large Red wires read  7 ohms to ground.  I suppose if one wire goes to the firewall solenoid then I could be reading the solenoid wire resistors to ground. 

My next step is to remove Fuse #10 thru #14 and see if the low resistance reading goes away.

Any thoughts?  This is a 72 pre L for reference.

Thanks,

John

#2551

what is the condition of your battery?   could be bad?

I had the local auto parts store do a check on the battery a couple weeks ago and it was good.  I'm going to go back and check all my high current connections, including the ammeter and see if that helps.

Thanks,

John

Where do you find a new one of these?  4 wire terminal?

“ terminal strip block”

make sure you get the style that compress the wire instead of the style that accepts ring terminals

Larry

Thanks I will try that search phrase. My original looks a bit smashed but working condition. A new one is good piece of mind and it will be the best looking thing under the dash.