My 70 Charger Dilemma.

[smithenhiven]

As some of you may recall, I bought a 70 Charger a couple months ago.  It was my dream come true, still is, despite my little predicament.

I was driving it the other day, and it just died out of nowhere, no warning at all, no sputtering or hesitations or anything, engine just cut out.  Thank god it was at low speed and still in a parking lot, so I just coasted to a stop, and put it in park.  Inside and outside lights still worked, so I figured I'd try starting it back up.  Cranked, but no fire.  Checked a few things and found it's not getting spark.  At that point, I decided to have the car towed to my trusted mechanic.

Few days go by, I get a phone call "bad news, seems your dash wiring is fried".  He's not really a wiring guru so he sent it back home to me, I didn't dig into it yet, but I'm guessing my car fell victim to the dreaded Amp gauge failure. I'm really pissed at myself for not tackling that issue ASAP, as I knew it was a potential ticking time bomb waiting to go off.  Thankfully there were no catastrophic failures resulting in a fire, and I'm thinking (hoping) a new dash harness will get it going again, but therein lies the dilemma.

To remove and replace the dash harness, one must remove the dash (correct???), and to remove the dash one must remove the windshield? 

My car has the original headliner and vinyl top, both of which need replaced, so if the windshield is out there's no better time to replace those right?  And if the vinyl top and trim is coming off, I might as well have the car repainted.  That's my problem, I'm not in a position to do a full resto on this car yet.  Since it's a really nice 20-footer, I was wanting to enjoy it "as-is" for the time being, and restore it down the road.

Has anyone had success of bringing their Charger back to life after dash wiring failures, without getting too invasive in removing everything previously mentioned?  Tomorrow I plan to tear into her a bit, remove the gauge cluster and what-not that's easily removable, and have a look to see if there's a run of wiring I can fix with the dash still in.  Maybe I'm just overthinking this issue, and it's not as bad as it appears *crosses-fingers*

[Kern Dog]

Usually if you can get the starter to spin by turning the key, the problem is not in the dash wiring.
If you need to replace the under dash wiring, it is accessible without pulling the dash frame or windshield. I did  some work on mine last Winter. After removal of the guage cluster, most of the wiring is in your face or at least within reach. There may be some retaining clips or straps that need to be removed, some that may not be visible at first glance.
Lets step back and look at the problem as if you first laid eyes on the car. Take a 3 foot section of "jumper" wire and attach one end to the POS side of the coil and the other end to the POS battery terminal. Now turn the key. If the car starts up and runs, the problem is somewhere under the hood and relatively simple.
You may need to remove the jumper wire to get the car to shut off afterwards.
I see that you do have some understanding of the Mopar Ammeter problem. These were okay when new but time and wear do have a negative effect on their reliability. Check out www.madelectrical.com for tips on how to bypass the ammeter and provide a safer alternative to power the inside of the car.

[GreenMachine]

As far as bypassing the ammeter, IMO usually all that really needs to be done is connect the alternator straight to the battery with a heavy gauge wire and leave everything else alone. You can do that from the output post on the alternator, or splice into the output wire at the bulkhead connector.  That will protect the bulkhead connector and dash harness from most of the charging current. Just like water flowing downhill, electric current will take the path of least resistance.  However the amp gauge won't read correctly. Also, One step better is to add relays for the headlights so all the current isn't flowing through the headlight switch and bulkhead connector.

To get back on the road, just cut out the melted wiring and splice in new, piece by piece. You'll probably have to remove the steering column. It's probably not very many and it's probably going to be around where the the welded splice is by the steering column. This is assuming your mechanics diagnosis is right.

I went though the same thing on the side of the road in my '70, 800 miles from home. I came prepared with a wiring kit I made up (spools of wire, dikes, crimper, zip ties, multi-meter, etc.). I was back on the road in an hour or 2. My Avatar pic was of that trip on my way back home a week later.

[DAY CLONA]

I get a phone call "bad news, seems your dash wiring is fried".  He's not really a wiring guru

I think this is your bigger problem? if he's no "guru"...second opinion if you yourself cannot diagnose the issue, it could be something as simple as the ignition switch harness pin connector under the column (common cause) that has burnt out preventing the car from being started, a loose bulkhead connector?, ballast resistor, etc, etc, etc, the list is endless if you don't know where to start...I find it hard to believe the entire under dash harness suddenly imploded...time to have someone competent in electrical service on an older vehicle at least look at the car  

[Brock Lee]

It died suddenly while driving. Then crank, but no fire..this may be a stupid question, but have you checked the ballast resistor?

[GreenMachine]

It died suddenly while driving. Then crank, but no fire..this may be a stupid question, but have you checked the ballast resistor?

A bad ballast resistor will cause the car to start while cranking, but dies when you let go of the key. But yeah, still worth checking, simple.

[JR]

I highly doubt the entire dash harness is fried.

Check the main power suppy circuit that runs from the starter relay-fusable link-bulkhead connector-ammeter-fuse box.

Id bet your problem is there, and the mechanic saw a burned wire on that circuit and went straight to "well, replace the whole harness".

Most mechanics would rather swap parts than repair something.


And worst case, if you ever do have to replace the dash harness, theres no need to pull the whole frame. All you have to do is pull the gauge cluster/glove box/dash trim.

[smithenhiven]

Thanks for all the tips, commemts and recommendations.  My guy did change out all the easily accessible items in the engine bay, such as: coil, ballast resistor, voltage reg, etc...  

Im gonna head out to the garage now to do a little digging myself.  Im no mechanic by any means, so we'll see if I cant find the problem.  I guess I feel a little more at ease after reading some of your guys' replies, here's to hoping its a simple and easy fix.

[myk]

Have an electrician go over the entire system.  Better yet, stop chasing your tail trying to patch together 50 year old wiring and rewire the whole car.  From a safety and performance point of view that's the prudent thing to do...

[crj1968]

I highly doubt the entire dash harness is fried.

Check the main power suppy circuit that runs from the starter relay-fusable link-bulkhead connector-ammeter-fuse box.

Id bet your problem is there, and the mechanic saw a burned wire on that circuit and went straight to "well, replace the whole harness".

This ^

I was really worried about my 70's dash wiring but when I got into it it all looked really good. I have bypassed the amp gauge.

A re-wire would be ideal (for me as well) as Myk points out, but in the meantime, that main circuit is the usual suspect.




 

[XH29N0G]

...
Im gonna head out to the garage now to do a little digging myself.  Im no mechanic by any means, so we'll see if I cant find the problem.  I guess I feel a little more at ease after reading some of your guys' replies, here's to hoping its a simple and easy fix.

We all have to start somewhere.  A number on here are mechanics and will provide fantastic step by step guidance.  Others, like me, are learning and slowly being self taught.  I think my work on the car I have has been one of the most satisfying things I have done.  It always has some issue, but it is always fixable, and each time, I learn more.  I found that buying a Factory Service Manual was one of the best things I did.  You can also find them online.  The manual has wiring diagrams, and if you look at them long enough, and trace out the wires, it is possible to figure out a lot about where connections are broken.  You will also need a multimeter (set to ohms) to check for continuity, or set to volts to check other things.  If you don't have one or haven't used one, I would look into that too.  It does not need to be an expensive one to do what we need.  Mine is probably a $20-$40 one from Home depot.  With this you should be able to diagnose. 

If you pull the instrument cluster, put a towel on the steering wheel column because it will scratch.  Also I always disconnect the battery when playing with wiring (actually whenever the car is off).

Good luck.

[Dino]

Even if it's something silly like a blown fusible link, and it just may be, I would advice to pull the instrument cluster to get a good look at the wiring behind it AND replace that stock voltage limiter with a solid state version from RTE. It'll ensure you'll never fry any of your gauges.

You have options regarding the ammeter. You can keep the stock one or buy a new one rated for 65 amps, bypass it completely by connecting the red and black wires, leave it and run a thick wire form the alternator to the starter relay to take the load off, or replace it with a volt meter. I did the latter and made it look like it belongs there.

Don't dread the worst just yet. If you didn't see smoke pouring out from the dash then it's probably not as bad as you think. And no you do not have to pull the dash to replace the wiring.

[b5blue]

I've a 70. Buy a new ignition switch and unplug yours. Look at the condition of the connector for it closely...is it melted around the big red wire? If not nasty plug in the new one and test without installing.

[BrianShaughnessy]

Certainly getting rid of ammeter is a good step.    Several guage resto shops will convert your ammeter to a voltmeter.

Another step to safeguard the ignition switch is to use that to run the turn on signal for a relay that carries the current for the ignition system.     A vender used to sell a pre-wired kit to do that which I installed on my '69 awhile back but they went under for some reason but I think one of the former partners runs Dixie resto now.   

As for stock ballasts...  eh...  I run an .8 ohm MSD.    Doesn't look stock... don't care.   It works.   Carrying a spare ecu in the trunk spares isn't a bad idea also.    They're all solid state more or less anymore.   

I would have a look at the bulkhead connectors tho...  it isn't hard for a wire to back out of the bulkhead connector.   It's only being held in by a small tang.

[69wannabe]

Get you a 70 model wiring diagram so you can see what you are working with. Wiring on these old cars isn't rocket science but I have had a few give me a fit or two. I am more used to the 68/69 wiring than the 70 and up with the switch in the column but still not a big difference I wouldn't think. Has your charger been converted to electronic ignition?? If so is it the mopar conversion? These orange boxes these days aren't as good as they used to be and seem to fail alot lately. And make sure if it does have an orange box on it that it is grounded good. Chased my tail for two days on a 70 cuda and the orange box had lost it's ground was all that was wrong with it.
Added a ground wire from one of the screws on the box to the engine and that fixed it. I could really use a new dash harness myself but I have a few donar harness's that I have kept mine going pretty good so i'm putting that off as long as possible!!! lol