Electrical gremlin. Dart won't start. Desperately seeking insight!

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Corrupt_Reverend

Corrupt_Reverend

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EDIT: this is a '72 dart 4-door

Okay, so this gremlin has popped up in the past, but never this persistently.

When it first happened, the can just wouldn't crank. So I popped the hood, jiggled some wires, and that was that. Started right up.

Then the car shut off a few times while driving down the road. No biggie, I pulled over, popped the hood, jiggled some wires and... it wouldn't start. Hmm. New fix: Open door, slam door shut, and bam! Started right up.

That was it for a couple months. If it stopped running, or just wouldn't start, I'd open the door or hood, close it hard, and it'd be fine. Still thinking it was just a loose wire somewhere, it wasn't a major concern.

Then it happened about a week ago. None of the above worked so in a last ditch effort, I moved the shifter from park, all the way to 1st and back to park. Tada! Started right up.

Now I've got a problem though. Nothing seems to be working. Er, at least none of my previous "remedies" are working. When I open the doors, the dome light turns on, and I have 12.58V at the battery. Yet, nothing happens when I turn the key. No click, no starter, no vroom to speak of.

I haven't had time to really get under the hood and troubleshoot yet but I'm guessing voltage regulator, a relay, or a fusible link? I dunno.

So my question to y'all is weather any of you have had this sort of issue and what your guesses are.

I won't be able to roll my sleeves up until Thursday and getting to work is a bit of a PITA now.

A million thanks to any and all who may share some wisdom (or even just guesses)

~Rev
 
Wait for 67DART273 or BillGrissom or any of the other electrical guru`s to post on this. They are a wealth of information and could explain it much better than myself.
 
The black plug that passes thru the firewall into the passenger compartment...
 
HemiTM said:
Sounds like the bulk head connector gremlin has found your car.
Click to expand...

inkjunkie said:
The black plug that passes thru the firewall into the passenger compartment...
Click to expand...

Yup. the huge big connector that passed all the wiring through the firewall to other circuits in the interior.

Start by reading this article for the hows and whys:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

Usable but not always complete electrical diagrams from MyMopar:

http://www.mymopar.com/index.php?pid=31

http://www.mymopar.com/downloads/1972/72DartA.JPG

http://www.mymopar.com/downloads/1972/72DartB.JPG

And you sir, are ONE lucky SOB, because you have a 72, you can download a 72 Chrysler shop manual right here

The thread:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download

Der linky:

[ame]http://www.abodyjoe.com/pictures/Misc.%20car%20info/1972%20Plymouth%20Chassis%20Serv%20Man.pdf[/ame]
 
I know someone who had a similar problem with a little Nissan p/u. I found remnant of a aftermarket security system still wired in under the dash.
 
Check the connectors for being plugged in all the way, and don't randomly pull at things.

I had an issue with my connector going from the ignition switch to the bulkhead. I found that the plug was worn out and would randomly lose contact which would shut the car off while driving down the road. It would also fail to start until I pushed the connector back together. I finally cut it off and rewired it, and all the problems went away.
 
IMAG0001-1.jpg
 
Playing with the shifter until the starter works is a classic sign of a mis-adjusted shift linkage or a bad neutral safety switch (nss) on the side of the tranny. Mis-adjusted is most likely. The factory manual will tell you how to adjust it, or just follow the shaft and look for an adjustable length piece and use common sense. You want the spring detents on the column to match the spring detents in the tranny's valve body.

Since it will also start in "N", you should always be able to move the column shifter around near there to find true "N" in the tranny and get it to start. All the NSS does is ground the wire from the starter relay coil. You can bypass it with a jumper wire, but not smart since it could then start in any gear and the car jump forward or back. A lot of gomers have been pinned to their garage wall fooling with that.
 
Oh, crap. I missed the part about starting in neutral. Either a misadjusted linkage, or a bad NSS.
 
Thanks for all the input folks. Luckily I've got tomorrow off from work so I'll be able to address this issue. I'll be sure to report back with my findings. :)

Thanks again!

~Rev
 
Alright. Was able to spend a little time checking things out today.

First thing I checked was the bulkhead connectors. I pulled all three and there was a bit of corrosion build-up. a few sprays of contact cleaner and some di-electric grease and that was taken care of... but still no start.

Okay, tested start relay. Works fine when jumped. Tried jumping with the key at "run" and while it would crank like a champ, still no start. Checked for spark while cranking. None.

Okay, so things are pointing toward something on the backside of the firewall. I was loosing light, so I just pushed the dart across the street and I'll do more work tomorrow. Just for ***** and gigles, I decided to turn the key after pushing it across the street... Vrooom!!! Damnitall.

I'm definitely thinking ignition switch of the wiring thereof. My logic is it started because of all the cranking/pushing on the steering wheel while getting it across the road.

I'll report back after poking around a bit more. First thing on tomorrow checklist is rnaz'z suggestion of the ign. switch plug.

~Rev
 
I would bet money on.................

poor connections in the bulkhead connector TOP of the list

MAYBE bad connections at the ignition switch connector second

Bad ignition switch next

Last is something like bad connections at the ammeter, or more rare a failed "in harness splice."

Read the MAD article I posted earlier for the hows and whys of this kind of trouble.

The circuit path for "ignition run" and there can be trouble ANYWHERE along the way AS WELL AS multiple problems

From the battery, -- fuse link -- bulkhead connector -- (big red main feed) -- to ammeter -- through ammeter -- to "in harness splice" -- (welded splice in the black ammeter lead, refer to the MAD article) -- to the ignition switch connector -- through the switch -- back out the switch connector (now on the "ignition run" dark blue wire) back through the bulkhead connector -- to the ignition and other points

On a 72, the minimum that the dark blue supplies is..............

cluster power to the gauges for warning lights and gauges,

out the bulkhead...............

supplies "ignition run" to the "switch" side of the ballast

field voltage to the alternator (light blue wire to field)

voltage to the voltage regulator IGN terminal

electric choke if used

Distributor retard, idle solenoid, and maybe another smog doo dad on some cars

This is EASY to check out. Turn the key to run, engine off. Check voltage at the blue field terminal of the alternator by "back probing" the field terminal as it's hooked up. Put your other probe on the battery positive post. You are hoping here for a very LOW voltage, the lower the better. Anything over .3V means you have a harness drop problem in the circuit path I outlined above.

Now just backtrack. Compare readings where the blue ign run comes out of the firewall, and the red in--feed.

Go inside the car and check at the ignition switch connector. If it's OK, but the readings on the engine side of the firewall are not, next get "down there" and backprobe the bulkhead connector. If it's "bad" (example) on the engine side of the dark blue wire, but the INSIDE of the bulkhead showls OK, then you know it's right there in the connector.
 
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