1969 Dart - Fusable link HOTTT!!!

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bloozeman2002

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Hey guys, I have a 1969 Dart 318 2bbl. I have an intermittent electrical problem. The car would die out randomly. I would wiggle the wire to the ballast resistor and it would start. I changed out the ballast resistor and it seemed to run fine for a while, and then it started happening again. The connection to the ballast resistor was good, but now loose. When I wiggle the connection, I can hear a "click" when the connection is made (somewhere away from the BR). I tightened the spade connector to make the connection solid. I was checking other wiring near the connectors at the firewall and burnt my fingers on the connection for the fusable link. I turned the key off and let it cool. I noticed that some of the insulation around the connector for the fusable link was melted a bit. What would cause this to heat up like this?

Thanks in advance for any help!

Tom
 
That ballast resistor is bypassed with the key in start. When you release the key to run it drops the battery voltage to roughly half to allow the coil to run cooler.

If wiggling the lead changes the problem, change the resistor. Its a cheap troubleshoot and you should keep a spare in the car anyway.

The hot fuse link may not be related, but old harnesses have their problems. If you upgraded to the HO alternator, you will have problems at the firewall connector and or the ampmeter. Those are problem areas even with the single wire alternator

If that fuse link is in your power to the resistor, you've got an intermittent short that's drawing too hard thru the fuse link and you're moving the wire and removing the short when you wiggle the lead at the resistor.

Maybe.
 
Actually, if that short is in the power to the resistor, it would overheat the fuse link, and cause the car to die for lack of voltage to coil
 
There are two things that cause heat in this manner.................

loose connections, which heat up, and either something drawing too much current, or a short doing the same thing.

However, leaving the key on with engine off WILL cause the ballast to heat up.

I'd check ALL connections in the immediate area.........the ballast, the bulkhead connector, etc.

Read this article from MAD:

Even though it's centered on the ammeter, it also points up the problems with these cars, the bulhead connector, and their related connectors.

http://www.madelectrical.com/electricaltech/amp-gauges.shtml
 
Leaving the key.in "off" heats the ballast?

How does the engine shut off when you turn the key to off?
 
Replace the fuseable link & pigtail wires in/out of it then see what happens. You probably have deteriorated or damaged wire around the fuseable link inside the insulation & there's high resistance at that point. Cant hurt to replace it after all these years anyway.
 
Thanks for all of the info. I will replace the link first. My concern with doing so was that if there was another problem that I might ruin a new fusable link. Not an issue if the fusable link IS the issue! :)

The connector is slightly deformed from the heat. I did order a new on from ebay. I think this one will be fine until then though.
 
You have a bad ground, a short or high resistance, probably in the wiring somewhere between the ignition switch and the ignition components or in the bulkhead connector. That's why the car cuts out. They key on (ACC) is providing 12V to whatever gets it. The ignition wires should only be hot when the key is in the start or run position. If you have resistance or a short, its going to take more voltage to get through whatever the problem is. That's the cause of the heat. I've seen many roasted connectors on old cars, especially Mopars.

I'd start looking at fuses, check/clean ground wires and look over whatever wiring you can with a fine tooth comb to check for cracked/chafed insulation and exposed wires. Also check for corrosion at the bulkhead connectors if you can, that's a common problem area. if you search, you'll find lots of stories about melted bulkhead connectors.

I also suggest to look into the voltage regulator. I had a '72 W100 that had one take a dump as I was sailing down the BQE one night. Truck just shut off while running - no power, no crank. The ballast wiring is spliced into the VR wire so that might be your problem. Might also be your click noise. Just a thought.
 
Hey guys, I am going to start working on this over the weekend. I have seen the schematics on changing the wiring when bypassing the amp gauge. The extra fusable link, and so on.. Can I take one terminal off the amp gauge, and stack it on the other, essentially bypassing the amp gauge, without making other changes? I'd like to just get her running...
 
The main reasons you sometimes need to bypass the ammeter is USUALLY not the ammeter itself, but rather poor connections in the bulkhead connector. You REALLY need to go clear through the system

The circuit path for example from battery to ignition is

battery -- starter relay stud -- fuse link -- bulkhead connector -- ammeter -- welded splice -- switch connector -- through the switch -- back out the switch connector (on dark blue ignition run) -- back through bulkhead -- and to ignition and regulator.

The above path does NOT describe the alternator charge line which is

alternator output -- bulkhead connector -- ammeter -- bulkhead connector -- fuse link -- starter relay stud -- battery.

So there is 2 VERY large current carrying terminals and 1 lesser terminal in the bulkhead subject to bad connections. This is not counting headlights low and high, which is two more, nor the left/ right turn which adds another two terminals.
 
bloozeman2002 said:
Hey guys, I am going to start working on this over the weekend. I have seen the schematics on changing the wiring when bypassing the amp gauge. The extra fusable link, and so on.. Can I take one terminal off the amp gauge, and stack it on the other, essentially bypassing the amp gauge, without making other changes? I'd like to just get her running...
Click to expand...

The idea is to remove the ammeter (weak link) from the circuit and splice the wires together - crimp, solder, heat shrink. That method would be the most robust. When wiring deteriorates, resistance goes up which requires more current to 'do work' (light bulbs, run accessories etc.) What happens is the alternator compensates by sending more current through the system. The design flaw is that everything passes through the ammeter. Often the gauge can't handle the extra load and subsequently gets roasted.

It sounded like you might have had an issue at the bulkhead connector which is theoretically what the ammeter bypass is supposed to help resolve. You're essentially reducing the main feed current flow through the connector and eliminating the connections where problems occur. That connector is a common area for corrosion and sees plenty of heat/vibration. It's a perfect environment for high resistance and shorts to occur. When you send enough current through high resistance stuff will start melting.

Did you check that area?
 
I apologize for my ignorance, or improper descriptions... I am really an amateur at this.

That bulkhead connector does look corroded at the connection that goes through to the ammeter. It has seen plenty of heat. It is slightly disfigured from heat. I do have to replace it. I have one on order, and I intend on correcting it.

That said..

A common change I have seen to the wiring is (as mentioned above) bypassing the ammeter. Thank you "67Dart273" for pointing out that it is usually not the ammeter itself. I thought that it was. I digress.. I was hoping to do a little of this at a time, maybe not a smart move? From what I have read, when bypassing the ammeter, guys were crimping and soldering the two leads together and then heat shrinking them. My thought, possibly flawed, was for a quick fix, I put both leads on the same terminal for the ammeter, essentially bypassing it. Current will not run through it then, right? I am guessing that this isn't as good of a connection as crimping and soldering, but is a bad connection? Still causing heat?

I have also seen where guys are drilling out that bulkhead connector, then running solid wire through it. This eliminates the factory connection at the bulkhead connector. This was going to be my second step, but would you guys advise against driving it before I complete this step?

I'm dying to drive it, and my free time to work on it is few and far between. I do not want to cause further issues though. Am I running a fire risk?

I hope I made sense!

Thanks!
 
So long as the eyelet connectors at the ammeter are not corroded internally AND THEY MIGHT BE, there is nothing wrong with hooking the eyelets to one stud.

The big problem remains "most of the time" to be the bulkhead connector terminals.
 
bloozeman2002 said:
I apologize for my ignorance, or improper descriptions... I am really an amateur at this.
Click to expand...

Don't sweat it, not everyone can be on the same level.

bloozeman2002 said:
That bulkhead connector does look corroded at the connection that goes through to the ammeter. It has seen plenty of heat. It is slightly disfigured from heat. I do have to replace it. I have one on order, and I intend on correcting it.
Click to expand...

The bulkhead connector is generally not a problem in and of itself. The issues occur when the circuits that pass through it and connect on the other side start to deteriorate. The spade terminals inside the bulkhead are not protected individually so they become the weak link. They pull apart, corrode, bend etc. If there is a short or resistance somewhere on either side, more current will pass through the connection than it was originally designed for. It may still sort of work but once the plastic housing that holds the spade terminal starts to melt, its basically junk and only a matter of time until it does real damage. That's when you get intermittent symptoms. It is definitely a good idea to replace it at this point. Really though, the only thing replacing the bulkhead does is allow you to start fresh and pack everything with dielectric grease. You still need to ensure all the circuits that pass through it are good or the same thing will happen. You need to look for chafing, corrosion, shorts etc. See which hole/holes are melted and use your wiring diagram to determine which circuit is in that position. Then you trace it on either side with a multi meter or at minimum a test light to find the problem. Then it will be fixed.


bloozeman2002 said:
A common change I have seen to the wiring is (as mentioned above) bypassing the ammeter. Thank you "67Dart273" for pointing out that it is usually not the ammeter itself. I thought that it was. I digress.. I was hoping to do a little of this at a time, maybe not a smart move? From what I have read, when bypassing the ammeter, guys were crimping and soldering the two leads together and then heat shrinking them. My thought, possibly flawed, was for a quick fix, I put both leads on the same terminal for the ammeter, essentially bypassing it. Current will not run through it then, right? I am guessing that this isn't as good of a connection as crimping and soldering, but is a bad connection? Still causing heat?
Click to expand...

It might work but you will be passing a lot of current through that little 1/4 stud behind the gauge and if you don't figure out why your bulkhead connector melted, you could melt your dash.

'Ol Dart273 is correct in saying that bypassing the ammeter does not solve any particular problem but prevents it from becoming a problem. Essentially, the entire electrical system is monitored by the ammeter which is a resistor. If current increases beyond the capacity of the resistor, you will melt it. Again, when currents deteriorate, resistance tends to go up which as always makes current go up. Basic Ohms Law.

bloozeman2002 said:
I have also seen where guys are drilling out that bulkhead connector, then running solid wire through it. This eliminates the factory connection at the bulkhead connector. This was going to be my second step, but would you guys advise against driving it before I complete this step?
Click to expand...

That's basically the Mad Electrical method. There's really no point in bypassing the ammeter if you're going to keep the connections in the bulkhead. Find the problem that's causing the extra current to pass through that circuit and fix it. That's what someone in a shop would have done way back when. To replace the bulkhead connector only or bypass the ammeter only is a waste, you would still have the same issue.

bloozeman2002 said:
I'm dying to drive it, and my free time to work on it is few and far between. I do not want to cause further issues though. Am I running a fire risk?
Click to expand...

Probably not likely but do you want to find out?
 
Thanks for all the help guys. I finally got to it this weekend. The connector at the firewall was the issue. The bottom right wire on the middle connector that goes to the ammeter was not getting a good connection (intermittant). The connector was disformed from heat, and the spade terminal was pushed in a bit. I believe that this was causing it to arc, and in turn, made heat. I cut the wire on each side of the terminal, and hard wired it and sent it through a gromet on the firewall. It starts much better, have driven it 75 miles with no cutting out, and the fusable link is cool to the touch.

SCORE!

I really appreciate all of you folks that took time to help me out.
 
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