Question on power for a few minutes then none

-
SGBARRACUDA

SGBARRACUDA

ROY
Legendary Member
Joined
Dec 7, 2006
Messages
22,009
Reaction score
10,663
Location
PLANT CITY FL.
I'm helping a fellow out getting his 70 slant 6 Duster back to driving condition. He was diagnosed with Liver cancer and has less than 2 years to live. He wants to drive his Duster again that hasn't been road worthy in about a year and a half. I went to his house and fired up the car and it ran pretty well for about 5 minutes, then it died. Nothing in the car had power. lights ,dash, ignition , I mean stone dead. After about 5 minutes we had interior power again and it ran again for about one minute, then dead again. Yesterday before I had his Duster towed to my house. His grandson fired it up and the same thing happened again to him. While I was there I checked the obvious battery connections, Power wire at the relay but no luck. I'm going to put it on the lift and start going through the wiring.
But I'm thinking that more than likely he has a bad amp meter? Any other thoughts? This is a pro bono effort on my part. The man just wants to enjoy his Mopar while he can. It has a bad bearing in the 7 1/4 rear which is what I was going to fix for him. I have a wiring diagram for reference.
 
How about horn and lights; Those dead too?
If yes, then it's most likely in the battery feed circuit to the ammeter. Follow the big fat 12 ga. red wire from the starter relay to the fusible link at the bulkhead connector, to the bulkhead connector itself, out the other side to the ammeter gauge, through the gauge and off to the, No1 factory welded Splice.From there it splits several ways; to the fuse-box, the horn sw, the headlight sw, out to the VR,and to the Ig Sw.
In all likelyhood you will find the problem at the F-link or bulkhead connector, under the hood.
Occasionally a wire comes loose off the ammeter..
The #1 splice is the least likely problem area.

As you may know, the engine can continue to run, on alternator power alone, with the battery + cable removed from the battery.
And the engine will continue to run with the alternator out of the circuit,until the battery dies.. But if the engine is running, and the alternator circuit quits, and the battery connection becomes too poor to continue to run the ignition circuit, the engine will stall.The same can happen if the ground circuit fails.
 
No lift req'd to go through wiring diagnosis. Where power comes and goes with vibration and/or temp change.... connections. Check ground battery to block first. The positive connections at fusible link, bulkhead, etc... good luck
 
Roy, good on you for the help. I personally would be looking at the bulkhead connector. Corrosion there could cause the current flow to drop as it heats up, resistance increases with heat. Just a thought.
 
Firewall connector, fusible link, ignition switch connector. As the current flows through a bad connection heat builds up and expands the metal connector to the point of an open circuit. When it cools down it all works again. I had a headlight power feed terminal on an old 67 Mustang do this.
I would also eliminate the ammeter by moving wire over so both black and red are on one terminal.
 
RedFish said:
No lift req'd to go through wiring diagnosis. Where power comes and goes with vibration and/or temp change.... connections. Check ground battery to block first. The positive connections at fusible link, bulkhead, etc... good luck
Click to expand...

No the lift is to fix the rear end bearing issue and go through the brakes. Yes I'm going to start at the positive wire on the relay and work forward.
 
mderoy340 said:
Firewall connector, fusible link, ignition switch connector. As the current flows through a bad connection heat builds up and expands the metal connector to the point of an open circuit. When it cools down it all works again. I had a headlight power feed terminal on an old 67 Mustang do this.
I would also eliminate the ammeter by moving wire over so both black and red are on one terminal.
Click to expand...

My thought too. I'm going to connect the two wires together on the back of the ammeter.
 
Hey thanks to everyone for your input on this. I did notice on the wiring diagram that there is a circuit breaker on the hot wire before the amp gauge, maybe opening and resetting.
 
SGBARRACUDA said:
Hey thanks to everyone for your input on this. I did notice on the wiring diagram that there is a circuit breaker on the hot wire before the amp gauge, maybe opening and resetting.
Click to expand...

There is no circuit breaker in original cars in main power, except......."some years" etc have


breaker built into the headlight switch for those

built into the wiper switch I think only earlier years

if the car is a ragtop I believe the top circuit does have an added breaker for the top

The main feed through the bulkhead power is "somewhat" protectected by one time fuse links out in the engine bay

If you can, post a reference to what you are seeing. What diagram are you reading? Generally factory shop manuals are superior.

MyMopar has free service manuals you can download

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

Also on that site are wiring diagrams SOME of those are aftermarket and not always complete

http://www.mymopar.com/index.php?pid=18

Please be certain to read this MAD article. Even if you don't do the modification, this article points out the problems with wiring, mainly, bulkhead connector terminals, ammeter, etc, and in some cases the ignition switch for some problems

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

The diagram they post there on that page is an excellent simplified view of the main power distro in the car
 
The one I'm referring to is from www.classiccarwiring.com by John Anastasio
This one is actually for my 69 Dart but figured it would be similar.


67Dart273 said:
There is no circuit breaker in original cars in main power, except......."some years" etc have


breaker built into the headlight switch for those

built into the wiper switch I think only earlier years

The main feed through the bulkhead power is "somewhat" protectected by one time fuse links out in the engine bay

If you can, post a reference to what you are seeing. What diagram are you reading? Generally factory shop manuals are superior.

MyMopar has free service manuals you can download

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

Also on that site are wiring diagrams SOME of those are aftermarket and not always complete

http://www.mymopar.com/index.php?pid=18

Please be certain to read this MAD article. Even if you don't do the modification, this article points out the problems with wiring, mainly, bulkhead connector terminals, ammeter, etc, and in some cases the ignition switch for some problems

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

The diagram they post there on that page is an excellent simplified view of the main power distro in the car
Click to expand...
 
Trace the heavy red from the starter relay and the heavy black from the alternator back to the firewall connectors. Pull each connector off. I'd bet both are green. You can remove each by pushing on the side of the male connector to retract the hook that snaps it into place, remove the connector and inspect it. Sometimes you can wire brush it clean, grease it, bend the connector out and snap it back into place. Other times there's so much heat from the resistance that it actually melts the wire and the plug. In that case drill two holes in the firewall and bypass the connections thru the firewall. On the interior side the female connector has a little locking tab you can push down with a paper clip of small jewelers screw driver to remove the wire from the harness.
Every old Mopar I do I pull every single wire one at a time from both sides of the harness connectors, male and female, wire brush them with a dremel til they shine, grease them and snap back into place. Then pack the female connectors at the firewall harness with grease and reconnect the plugs. I imagine dielectric grease would be better, but I use wheel bearing grease that has no moly or anything metallic in it.
 
SGBARRACUDA said:
My thought too. I'm going to connect the two wires together on the back of the ammeter.
Click to expand...

That's a lotta work for number 3 in the order of problem likelyhood. But if you go this route, be sure to disconnect the battery, cuz the only fuse in that circuit is the fusible link, and it is pretty slow to puke, unless you connect the wire straight to ground; then it gets hot in a hurry and makes more work for you.Maybe a whole lotta more pro-bono work
 
Since the headlights did not work it is going to be:
- fusible link (they can and do get erratic)
- firewall connection
- ammeter
- welded splice

Good for you and for what you are doing there! That is very kind.
 
SGBARRACUDA said:
The one I'm referring to is from www.classiccarwiring.com by John Anastasio
This one is actually for my 69 Dart but figured it would be similar.
Click to expand...


That might be OK for an "easy quick" reference but not accurate

If you download this (copy and past into a browser URL)

mymopar.com/downloads/1970/70_Dart_Challenger_Wiring_Full.pdf

is essentially an excerpt from the full Mopar shop manual, except that it's just the wiring. There is one mistake for a few years there..........the horn wire (dark green / red) and the starter relay "start" wire (yellow) are shown incorrectly where they go through the bulkhead connector

Page "2" (8-85) of that document show the circuit breakers listed (factory)

Once again, the MAD ariticle I referenced gives a very good overview.

These are the aftermarket diagrams from MyMopar. Again, they leave some things out. These "can" be easier to follow

http://www.mymopar.com/downloads/1970/70DartA.JPG

http://www.mymopar.com/downloads/1970/70DartB.JPG
 
Thanks, I'll look into it tomorrow. I made some copies of these diagrams.


67Dart273 said:
That might be OK for an "easy quick" reference but not accurate

If you download this (copy and past into a browser URL)

mymopar.com/downloads/1970/70_Dart_Challenger_Wiring_Full.pdf

is essentially an excerpt from the full Mopar shop manual, except that it's just the wiring. There is one mistake for a few years there..........the horn wire (dark green / red) and the starter relay "start" wire (yellow) are shown incorrectly where they go through the bulkhead connector

Page "2" (8-85) of that document show the circuit breakers listed (factory)

Once again, the MAD ariticle I referenced gives a very good overview.

These are the aftermarket diagrams from MyMopar. Again, they leave some things out. These "can" be easier to follow

http://www.mymopar.com/downloads/1970/70DartA.JPG

http://www.mymopar.com/downloads/1970/70DartB.JPG
Click to expand...
 
Well I did fix the stalling issue. It was in the bulk head connector, clean the terminals and applied some dielectric grease and she is good to go! The poor guy loves this car and man is it a rust bucket. But I told him I would get it squared away on the mechanical side so he can drive it. On a good note the frame rails and all the safety issues are good. I'm rebuilding the rear end and brakes, other misc stuff. I'll get some pictures of it tomorrow and post them.
 
I've been working on the Duster and made some head way. Found the head light switch and dimmer switch ( both rusted up ) were bad and replaced those.But I'm in need of a cluster like the one pictured. This one is in very poor shape, corroded terminals , Rusted up ammeter gauge. Sorry about the pictures on the lift. I'll get a few of it when I get it on tires. So if anyone has a cluster let me know.---Thanks
 

Attachments

  • 71 duster cluster.jpg
    60.5 KB · Views: 111
  • 71 duster.jpg
    49.3 KB · Views: 133
  • 71 duster-2.jpg
    54.6 KB · Views: 116
  • 71 duster-3.jpg
    50.9 KB · Views: 121
Well Ed is able to drive his baby again. Took a couple of pictures of Ed's Duster before he came and picked it up.
 

Attachments

  • eds 71 Duster.jpg
    65.5 KB · Views: 97
  • eds 71 Duster-2.jpg
    63.7 KB · Views: 95
Rust bucket? Looks pretty decent from here.

Good karma heading your way for helping the man.
 
Good Man you are, to help out like that !! Payin it forward is always good !!
 
What's that odd green stuff under and all around it?
 
Trust me the pictures don't tell the true story. It is rusty but hey he was happy. That green stuff is fricky grass that should be dormant but thanks to the mild winter the stuff keeps growing!
 
You must log in or register to reply here.
-

Back
Top