Author Topic: Ground points for 68  (Read 4592 times)

Offline ruppstang

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Re: Ground points for 68
« Reply #15 on: October 16, 2016, 12:34:52 PM »
I would run a temporary wire from the hot side of the solenoid to the coil and go for a drive and see what happens. You will have to remove it to stop the engine.

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Re: Ground points for 68
« Reply #16 on: October 16, 2016, 01:00:42 PM »
I had to do a bit of wiring for the Pertronix II so I didn't lose the tach feed and had a constant 12V hot.  I was wondering if he had a Pertronix. If the tach fails or is intermittent in operation it cuts the feed to the coil as well.

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Offline 68 S Code

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Re: Ground points for 68
« Reply #17 on: October 16, 2016, 04:05:42 PM »
No factory Tach but i am unsure of the underdash wiring harness as i did install a tilt column from a 68 GT Fastback i once had back in the late 80's. i remember grabbing all the tilt components and don't remember if it was a sub harness or the entire dash harness. That car did have a tach and AC which my vert did not.

Yes still running points. That was going to be a future question though. Distributor is going back to Tim O'Connor in the next two weeks because something not right with mechanical and vacuum advance numbers. How have people faired with the Petronix upgrade?

Offline ruppstang

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Re: Ground points for 68
« Reply #18 on: October 16, 2016, 04:19:57 PM »
It could possibly be connected to the tilt. The ignition circuit runs through the tilt wiring so when the wheel is tilted it will not start. The test I suggested above will by pass all of that.

Offline carlite65

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Re: Ground points for 68
« Reply #19 on: October 16, 2016, 05:13:33 PM »
No factory Tach but i am unsure of the underdash wiring harness as i did install a tilt column from a 68 GT Fastback i once had back in the late 80's. i remember grabbing all the tilt components and don't remember if it was a sub harness or the entire dash harness. That car did have a tach and AC which my vert did not.

Yes still running points. That was going to be a future question though. Distributor is going back to Tim O'Connor in the next two weeks because something not right with mechanical and vacuum advance numbers. How have people faired with the Petronix upgrade?

good luck with tim. his website says closed until further notice. been that way for several months now.
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Offline 68 S Code

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Re: Ground points for 68
« Reply #20 on: October 16, 2016, 05:36:28 PM »
I'm already in line with a dual vacuum advance unit for a while now. He told me to send it in but i was hoping to add another 250 miles to break the motor in before winter and the distributor pull.

Well I pulled the cluster. i can see the tiny screw at the ring from small gauge black wire being grounded to the LH steel vertical brace. Just picked up some star washers so will get that one. The ring is clean as is the paint off the brace. But I'll give it a go.

Don't really know where to look for that other grounding ring for the main harness though. Lots of harness in the way. Hints or picture would be great.

Offline 68 S Code

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Re: Ground points for 68
« Reply #21 on: October 16, 2016, 06:00:20 PM »
Regarding the jumper wire that could be an issue. The wire from ignition switch to coil is actually only supposed to be 6 volts due to an inline resistor. Trying to feed the coil with 12v directly  probably not a good idea. However when i bought the MSD coil the directions mentioned a 0.8 ohm resistor so I bought it and installed it on my temp apron coil bracket. When i got stuck on Weds my son thought of the direct feed. He didn't want to leave it out on the street all night. So we grabbed a jumper wire and some of the wiring I had made for the resistor earlier this year. We wired 12 v from the battery to the resistor and a jumper from the other side of the resistor to the coil. It started but died like before. All we noticed is that the resistor got pretty hot. My big format wiring schematic shows the inline resistor. That very well could be the problem but just looking at the bowl of spaghetti under the dash difficult to spot it.

Regarding the tilt column i don't have any of the tilt electrical components, vacuum pump etc installed. i just use the manual tilt feature and not the swing away as it wasn't important to me. i now have someone who could get the swing-a-way restored and working but first i need to make the car dependable. The tilt column shouldn't have anything to do with ignition. The turn signal switch could be my issue with turnsignals but it doesn't make sense why the brake lights would be affected as they dont have anything to do with that switch. There is a Black with green stripe wire i believe 465 (?) which could affect almost everything according to the schematic.
« Last Edit: October 16, 2016, 06:08:54 PM by 68 S Code »

Offline ruppstang

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Re: Ground points for 68
« Reply #22 on: October 16, 2016, 06:59:52 PM »
The jumper wire with 12V will work just fine to test, in fact when you have a original points system when you have the key turned to start there is 12V to the coil the help with a hotter start. Then when you return the key to on it goes through the ballast resistor to save wear on the points.

Offline 67350#1242

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Re: Ground points for 68
« Reply #23 on: October 16, 2016, 09:14:03 PM »
Sounds like you may have more than one electrical problem.  Don't discount TS switch relating to brake lights, the wiring does pass through the TS.   At the TS plug, look for orange/blue (RH tail light)  and Green/orange (LH tail light). 

Often times can be the TS connector itself and not the switch.   I had intermittent brake light problems that turned out to be the crimp connections on the wires at the TS switch plug.   You have to pull the wires from the plug with special tool and recrimp and/or solder them to repair.  Usually wiggling the connector will cause problem to come and go if connections are flakey.

I don't think the brake light issue is related to the ignition problem.  I would try wiggling wiring and connections while the engine is running to try to isolate the trouble.   Have you checked the engine gauge harness plug that runs out to the coil?  This harness carries power from the pink resistor wire to the coil.
Just some thoughts - Kurt.
67 Coupe SJ 11/16/66
67 GT350 SJ 2/01/67

Offline 68 S Code

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Re: Ground points for 68
« Reply #24 on: October 16, 2016, 10:16:28 PM »
Good points by both of you. What i can say is that this NOS switch crimped connectors didn't want to seat as nicely as the original or even the Scott Drake repop. The repop failed on the turn signal cam almost immediately and never cancelled from the start. That's why i went with the NOS unit at great expense. Not sure why the pins didn't want to seat but ultimmately had to lightly adjust the tabs with an exacto knife blade.

Well with the cluster out I started to look around and noticed that the connectors between harnesses in lower LH side of dash were not seated all that great. Flat black, red block and black block just not driven home tight. Couldn't do much by hand so took some channel lock pliers opened up all the way and carefully made a solid full connection. I saw the pink wire at one of these blocks. Im hoping this is going to make a difference.  If the main harness ground is that tiny black wire with a internal star loop going to the LH side dash brace i got that one. Any more I should be looking for for the dash harnesses? I'm hoping tightening up the connector blocks is going to make a difference. The flat one seemed to have an 1/8" gap. Saw a lot of pins semi exposed.

The turn signal switch may need some additional work but I want to test it with the connectors fixed. Can i drive around without the cluster back in place?.

1967 eight barrel

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Re: Ground points for 68
« Reply #25 on: October 17, 2016, 12:26:40 AM »
As far as the intermittent ignition problems, it wouldn't be ground related. Have you bothered to change the condenser?  It may be breaking down internally after it gets hot. I did see a vehicle like this too that the neutral safety switch caused a similar issue.  I have noted that I have seen the feed to the coil as low as 5.3V with the key in the run position.
P.S. How did you relocate the coil to the right apron? I'd put things back here they belong, check voltage. If that is good, change the condenser. See what happens.

Offline midlife

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Re: Ground points for 68
« Reply #26 on: October 17, 2016, 08:11:54 AM »
Good points by both of you. What i can say is that this NOS switch crimped connectors didn't want to seat as nicely as the original or even the Scott Drake repop. The repop failed on the turn signal cam almost immediately and never cancelled from the start. That's why i went with the NOS unit at great expense. Not sure why the pins didn't want to seat but ultimmately had to lightly adjust the tabs with an exacto knife blade.

Well with the cluster out I started to look around and noticed that the connectors between harnesses in lower LH side of dash were not seated all that great. Flat black, red block and black block just not driven home tight. Couldn't do much by hand so took some channel lock pliers opened up all the way and carefully made a solid full connection. I saw the pink wire at one of these blocks. Im hoping this is going to make a difference.  If the main harness ground is that tiny black wire with a internal star loop going to the LH side dash brace i got that one. Any more I should be looking for for the dash harnesses? I'm hoping tightening up the connector blocks is going to make a difference. The flat one seemed to have an 1/8" gap. Saw a lot of pins semi exposed.

The turn signal switch may need some additional work but I want to test it with the connectors fixed. Can i drive around without the cluster back in place?.
Loosely mated connectors can be a problem.  You can drive without dash so long as you don't have a tach or bypass it if you do.  No other grounds in the dash area.
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Offline 68 S Code

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Re: Ground points for 68
« Reply #27 on: October 17, 2016, 09:58:07 AM »
8 Barrel yes I did swap out the condenser already as that was mentioned by a local mechanic. Neutral safety switch may be original or a very old (25 year old) replacement. The coil was relocated using a bracket off a Miata. Initially i thought that the engine was really hot before breaking in the motor and heating up the coil. Just wanted to take that out of the mix. Having temporarily installed a real temp gauge the coolant temp stays in the 180-195 range with a slight spike to 205 if i get stuck in traffic or a RR crossing. Once moving it drops down. Once I take her out and if the problem seems solved I will reinstall the coil to the intake. I hate that I had to pull so much stuff like the original smog system to get even this far. Trying to set timing with the original smog pump in place is impossible.

Offline 67gtasanjose

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Re: Ground points for 68
« Reply #28 on: October 17, 2016, 11:08:08 AM »
WOW! This seemed like something so easy to find when I first started reading this thread. Maybe try to KISS it. (K.eep I.t S.imple S-code)

The Neutral safety switch has NOTHING to do with the ignition system wiring at all! It only is a part of the STARTER circuit & Reverse light circuit. You can leave this idea out of the hunt.

I am with Marty on this one. If the wiring issue persists AFTER the squeezing of those connectors AND the checking of the under hood connection of the engine feed harness, try using a ballast resister off of a 1960's chrysler product and simply Hot Wire the ignition system between a direct connection at the battery and on the "+" (POS) post of the coil (by-pass the car's harnesses completely)and quit chasing your tail.

ONCE the car either stays running OR the car continues to stall out, THEN you can search in the correct area of the trouble.
« Last Edit: October 17, 2016, 11:10:42 AM by 67gtasanjose »
Richard Urch

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2005 (04/05) GT Premium Convertible, Windveil Blue, Parchment Top w/Med. Parchment interior,  Roush Body Appointments

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Re: Ground points for 68
« Reply #29 on: October 17, 2016, 01:40:41 PM »
Rich,
The NS switch does interrupt the ability to start the vehicle. I assumed it cut the power from the solenoid as well. I've never had a Ford with an automatic transmission with the exception of a '66 Tbird.  However, a ground isn't the likely culprit for intermittent operation.

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