Cranks but won't start. Unplug ground at field spade on Alternator and it starts?
- Thread starter 340sFastback
- Start date
-
340sFastback
Well-Known Member
Dale Davies
Well-Known Member
Starters draw down the battery voltage during cranking to about 8 volts. The points ignition systems were designed to function on about 8 volts, so that during cranking you had full spark. That is why Mopar vehicles are famous for their ballast resistor. The run position of the ignition switch supplies voltage to the one end of the ballast, while the other end supplies the 8 volts to the coil + terminal. The start terminal has a wire that supplies cranking battery voltage to the coil + terminal.
Supplying the coil with running battery voltage would burn the points quickly.
Mopar coils have two primary terminals, 1 + and 1 - that goes to the distributor.
Some use a different coil (Ford) that had a ballast resistor built in and 3 primary terminals, 1 + batt, 1 - to the distributor and 1 start that gets volts from the start terminal on the ignition switch or from the starter.
Do you have 8 volts at your coil while cranking? Is there continuity in the wire from the ignition switch start terminal to the coil? Strange it worked for 2 weeks and then pooped the bed.
340sFastback
Well-Known Member
I reported voltage readings at coil in post #19. It appears I have a voltage drop issue and its 100 degrees in garage so haven't tracked it down yet.
67Dart273
Well-Known Member
Either none of this is true or VERY poorly explained.
The entire purpose of IGN2 is to supply starting voltage in the form of full battery voltage to the coil during cranking. AND THAT VOLTAGE is supposed to be 10-10.5 or more during cranking, NOT 8V. In fact, coil voltage through the ballast, if it were supplied that way during cranking would normally be much LOWER than 8V perhaps as low as FOUR volts
You are right about one thing. An old Mopar SHOULD start IF the cranking voltage was as low as 8V say "winter" or with a low battery. But it might not start easily, and I would not depend on that
340sFastback
Well-Known Member
The 7 year old battery that was in car when this first began was 10.5 volts when cranking. Bought new battery and its 11 volts when cranking and 12.5 volts at rest. Hopefully I can get back out in garage soon to insure during cranking where is that voltage drop to coil happening. Most likely at bulk head connector but need to measure along path of circuit to find where that drop occurs. Full battery voltage should go through bulk head and back out via Ign 2 circuit and its not. But got stumped on 'I Got Zero Ohms cant be wiring' mind set and thinking like that isn't gonna get the car fixed....
Last edited:
Swinger 340
Well-Known Member
Just a thought. Years ago, my Dodge van would start, then when I released the key, the motor would stop. Ballast was the fix.
340sFastback
Well-Known Member
Decided to pull bulk head connectors off and inspect. Also pulled fusable link connector at firewall apart. All looks clean no signs of corrosion or connector melting ect.
New engine headlight M&H harnesses around 2009 or so. At that time bulk head was sprayed with electrical contact cleaner and packed with dielectric grease. Car driven around 5k miles since and kept in garage. Hood to cowl seal in place to keep water off firewall when washing car ect...
New engine headlight M&H harnesses around 2009 or so. At that time bulk head was sprayed with electrical contact cleaner and packed with dielectric grease. Car driven around 5k miles since and kept in garage. Hood to cowl seal in place to keep water off firewall when washing car ect...
340sFastback
Well-Known Member
This is a no start when cranking so its a different problem then what you had. I wish it was an easy common problem like you had with your van.
340sFastback
Well-Known Member
Voltage test of Unilite power wire:
1) Cranking engine, everything hooked up: 1.3 volts (no start)
2) Cranking engine, voltage regulator Ign 1 OR field wire disconnected: 10 volts (starts)
3) Cranking engine, voltage regulator and field connected, black battery wire at alternator disconnected, no start
So when voltage regulator Ign 1 and field wires are hooked up voltage at Unilite is at 1.3 volts no start. But disconnect voltage regulator OR field wire and Unilite voltages goes to 10 volts and it starts?
A new auto parts store voltage regulator installed and no difference from other voltage regulator. Swapped on old alternator which worked no difference.
Disconnected field wire at alternator and voltage regulator, ran a jumper wire between the two, no start.
1) Cranking engine, everything hooked up: 1.3 volts (no start)
2) Cranking engine, voltage regulator Ign 1 OR field wire disconnected: 10 volts (starts)
3) Cranking engine, voltage regulator and field connected, black battery wire at alternator disconnected, no start
So when voltage regulator Ign 1 and field wires are hooked up voltage at Unilite is at 1.3 volts no start. But disconnect voltage regulator OR field wire and Unilite voltages goes to 10 volts and it starts?
A new auto parts store voltage regulator installed and no difference from other voltage regulator. Swapped on old alternator which worked no difference.
Disconnected field wire at alternator and voltage regulator, ran a jumper wire between the two, no start.
Last edited:
340sFastback
Well-Known Member
Voltage test after I plugged bulkhead back in:
Battery: 12.4 volts at rest
Battery while cranking: 10.5 volts
Coil + side while cranking: 9 volts
Red bulkhead wire, inside car, at rest: 12.3 volts
Red bulkhead wire, inside car, cranking: 10.3 volts
Brown Ign 2 wire at bulkhead, inside car, cranking, 9.3 volts
All the above with Voltage Regulator and field wire connected, cranks, starter sounds very strong, no start, sounds like zero spark.
Battery: 12.4 volts at rest
Battery while cranking: 10.5 volts
Coil + side while cranking: 9 volts
Red bulkhead wire, inside car, at rest: 12.3 volts
Red bulkhead wire, inside car, cranking: 10.3 volts
Brown Ign 2 wire at bulkhead, inside car, cranking, 9.3 volts
All the above with Voltage Regulator and field wire connected, cranks, starter sounds very strong, no start, sounds like zero spark.
67Dart273
Well-Known Member
Do you have a multimeter with a 10-20A ammeter scale, and know how to use it? Try unhooking that field circuit, then insert your meter and see what that circuit is drawing, both, with key in "run" and with key in "crank"'
Explain the "unilite power wire?" Where does it get power?
I've heard some pushback on unilite, seems like they might be failure prone.
Explain the "unilite power wire?" Where does it get power?
I've heard some pushback on unilite, seems like they might be failure prone.
340sFastback
Well-Known Member
Yep well aware of all the bitching moaning whining complaining all over the internet Unilites are trash junk useless garbage. My Unilte been on there since 2009 and up till now not a single issue. Put one on my buddies 350 chevy 20 years back never a problem.
I updated the diagram several post back that shows Unilite wired in. Been like that since 2009. Checked Unilite ground zero ohms to neg battery.
Looks like my meter goes to 10 amps.
mopar head
Well-Known Member
Still have your old dist.? At this point I`d be trying another to put the unilite out of the equation.
Nevermind you say it works , but an alternator issue.
Nevermind you say it works , but an alternator issue.
340sFastback
Well-Known Member
While I went into house cause its 100 degrees in garage I left battery on 2 amp charge for 4 or 5 hours.
Field current readings:
Key in run: 1.4 amps
Cranking: 1.12 amps
All the sudden car now starts? And starts every time?
Unhooked amp and hooked field wire in engine harness back up. Starts every time and sounds like strong healthy start.
Some more voltage tests:
Volt drop at Ign 1 at VR, disconnected at ballast and VR, engine off .2 volts and spec is .55 volts or less.
Carb stud to neg battery terminal, engine running: .05 volts
VR body to neg bat terminal, engine running: .05 volts
Alternator to positive battery volt drop, engine running: 1.5 volts
Alternator battery stud, engine running: 15.6 volts
Battery engine running: 14.2 volts
Battery after taking for short drive, engine off: 13 volts. Banged some gears light throttle car seems to run really good. Amp meter shows it was charging, meter steady while driving, and was reducing amount of charge as I drove
Last edited:
mopar head
Well-Known Member
Intermittent stuff will drive you crazy. I`d rather have something fail completely, than worrying if it`s going to leave you stranded down the road.
Good luck.
Good luck.
340sFastback
Well-Known Member
Yeah I make sure towing insurance card with phone number and charged cell phone.
340sFastback
Well-Known Member
Yep, you will never know if you fixed it till it never happens again!
For a week it consistently didn't start and now it consistently starts this evening so who knows? I'll take it for a few more drives this week and if it keeps behaving go ahead and make the 1 1/2 hour drive to Carlisle? Live life dangerously?? Haven't been flat bedded home yet but I am working on it.....
You stated this:
"This was the voltage regulator that had been on there for 20 years that died 3 weeks back and was replaced by the mechanical one from Napa:
https://shop.advanceautoparts.com/p...gulator-raa1052/12450617-P?selectedStore=2623
The local parts store says they can have one this afternoon."
As I'm reading through this long thread of troubleshooting, it appears to me that it all your problems started after putting in the new voltage regulator.
I would try putting in the NEW voltage regulator that matches the one that went Bad.
"This was the voltage regulator that had been on there for 20 years that died 3 weeks back and was replaced by the mechanical one from Napa:
https://shop.advanceautoparts.com/p...gulator-raa1052/12450617-P?selectedStore=2623
The local parts store says they can have one this afternoon."
As I'm reading through this long thread of troubleshooting, it appears to me that it all your problems started after putting in the new voltage regulator.
I would try putting in the NEW voltage regulator that matches the one that went Bad.
340sFastback
Well-Known Member
The no start issue comes back if battery voltage drops from car sitting over night with voltage at 12.6 volts. Battery is new. If I charge battery get it to 13 volts or more car will start.
I had parts store order another one like I had but what cane in box was old style regulator. Put that on no difference. I do have a new Standard VR128 that just came too.
There is no sense in throwing parts at it if I am seeing a 1 volt drop in Ign2 circuit and a 1.5 volt drop from alternator output to battery engine running. The cars wiring bad connection issues needs to be tracked down and fixed.
Two evenings ago I went to start car. Sounded like no spark issue then it sparked in Start position. Saw Amp Meter swing all the over to Charge shake around a bit then quickly move toward center. Battery was 14 volts before starting car. Drove car for 50 minutes AC and radio on. Amp Meter very slight lean to charge, needle still in the white gauge center, and stable at idle and cruising. Came home, shut car off, and car fired right back up. Came back out next morning battery 12.8 volts or so strong crank no start.
340sFastback
Well-Known Member
If I run jumper from battery to Ign2 at ballast I measure 3.4 amps in field circuit with alternator pulley stationary.
Haven't tracked down the Ign 2 one volt drop. One volt drop at VR Ign 1 key in Run ballast disconnected engine off. 1.5 volt drop between alternator output and battery + engine running. Based on old threads I found these readings all point to a wiring issue, dirty/loose connections restricting current flow. So I need to track down and fix those issues so I can get the voltage drops down to an acceptable level.
Last edited:
340sFastback
Well-Known Member
Female red wire battery bulkhead terminal had corrosion. First picture was after I sprayed contact cleaner on it and used needle nose vice grips to push a male Packard 56 terminal in and out at which time terminal pushed into car cause tab on terminal not bent up enough to hold it in housing. That red wire female terminal was not fully seated in firewall housing when no start issue occured. But seating it a week or so ago did not fix it apparently due to corrosion.
Sprayed contact cleaner on all female connectors, moved spade terminal in/out sprayed some more, used miniature wire brush got them shiny.
Engine harnesses are M&H put on around 2009 or so. Used miniature wire brush to get male connectors shiny even though already clean.
Last edited:
67Dart273
Well-Known Member
It would be better to replace those terminals. Some of the supply sources have changed/ dried up so you will have to search. "Packard 56" and various. Be CAREFUL that the terminal has the tension area wrapped around the sides as exactly in your photo. There are some different ones that bend over the top and they will not fit some Mopar connector shells
I know Mattox has done some posts on this.
The other thing is, if you get this finally settled down, working, but still have some voltage drop in the IGN1 "run" circuit, that will cause overcharging as the VR sense will be low
One way around that is to electrically break the "run" IGN1 coming out into the bay, use the end from the switch to fire a relay, and supply the relay contact power from say, the starter relay big stud, and then put all the underhood "run" loads on the switched contact.
I know Mattox has done some posts on this.
The other thing is, if you get this finally settled down, working, but still have some voltage drop in the IGN1 "run" circuit, that will cause overcharging as the VR sense will be low
One way around that is to electrically break the "run" IGN1 coming out into the bay, use the end from the switch to fire a relay, and supply the relay contact power from say, the starter relay big stud, and then put all the underhood "run" loads on the switched contact.
-
