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'71 R/T Rallye Dash Problem

Started by lumpy, June 09, 2007, 07:30:26 PM

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lumpy

I purchased this car recently, it is a '71 R/T and is 99% stock and untouched. When the previous owner purchased it, it had a bad fuseable link in the engine compartment. He replaced it and when he turned on the ignition it fried some wires underneath the dash. He said that he thought it was probably a bad altmeter, and it should have blown the fuseable link, but he installed the wrong link for this car. My goal right now is to get power to the car , so I can start it and move it under it's own power. Can this be done without replacing the under dash harness? I am attatching a pic of the damged wiring. Can this portion be purchased speratley, or do I have to buy a complete new harness? Can I disconnect the bad altmeter, and star the car? Any help would be appreciated.

lumpy

The only damaged wire is the center red wire. It is a heavier guage than the rest of them. He was able to shut off the power quickly, preventing any serious damage to the rest of the electrical system (I hope).

Charger1973

You know what.  My car had the same wiring issue.  It was like that when I got it though and I dont know why or when it happened.  But the plug was melted in the same spot and spliced together outside of the plug.  It runs fine now so I have no clue but I am interested to know what you find out. 

Nacho-RT74

tipical ::)

If you already cut the wires only solution is use separated plugs on every wire ( male-female ). On those days, the plugs where available at dealer but not actually... you would need to get the underdahs harness and ignition switchm or get terminals ( maybe Radio Shack have similars ) and reuse some donor plastic insulation

but as stated if you already cut, then just attach terminals ( male and female ) and plug them separtely. Now you have the chance to get better quality and amperage flow terminals.

before you make anything... check the short cause
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

lumpy

Thanks for responding. The rewiring won't be the problem, I just need to know what caused it. Any Ideas?

Nacho-RT74

of course just a short... where ? good question.

Once I got a short on alt brush isolator what broken and then blue wire on same plug got melted. Of course this blue wire is teh one that feeds the alt brush and everything on engine harness.

So if we think the short came on only the red wire, I don't think is located on engine bay even we never know and allways is something to check.

One way to analize where did happen is where start the melted area. the worst melted area is the first to got melted, of course because is the area that it was more time to the overheat and it means then started there. ( damn I'm starting to look like a firefighter LOL ).

It does look the red section more overheated/melted is the plug coming from the ignition key ( male ) ? red small wires says me that since those are the ones coming from ignition key buzzer sensor. On underdash harness they become black. I would start checking inside the column.

Once I was doing something ( dunno remember what, was long time ago ) and when I fit the column underdash, an connected the battery, I got ignition key in buzzer buzzing allways, and key wasn't inserted... after check everything notice one of the ingition key buzzer sensor ( switch ) was betwen bracket and column and cover got broken, making wires got exposed and grounded. I had to dissasembly and tape the exposed wire.

Recently I got ignition key buzzer sensor damaged and when I was replacing was very lazy to unjoin everything, so I tied the terminals to a nylon wire to  use this nylon to guide the new wires throught the column, pulling it. When I was pulling the new sensor wires they got stuck and then came with a piece of red wire cover cut by sensors terminals... DAMN!!! I unjoined and got the red wire exposed. I had to tape it...

These two experiences I have had is juts examples about what is posible to happen inside column. Probably some day in the past some of this stuff could happen to last owner or some "tech" and never got problem untill wires got moved inside and then grounded, making the short.

For a short on underdash you could make a continuity check, between red wire and body ground. If you get continuity, then short is somewhere in the car and not inside column. start unplugging plugs everywhere untill continuity come off, then would it mean THERE is the short. If you unplugg everything the short is underdash. Could it bee ammeter wires some loosen and making cluster ground.

Now you are on this deal, check for melted areas on bulkhead. Is a tipical area to get melted on red and black wires coming from batt and alt. They get melted by stress and overheat with time and overcharge at High RPMs when you don't have an good average load coming from alt. This is to prevent some future melt there. This does not mean the fail is there, is just a checking to know the health of this.

When checking the short by continuity test, be shure the fuse link wire is not grounded.

This time does look you have a big short so is not time to this check, but to know you have a consumption on car there is a way to know... unplugg the negative side of batt and insert a 12 volts bulb in serie between negative side  of battery and negative black  wire. Of course be sure you don't have anything working or key on ignition swtch. If you have ignition key courtesy light, wait untill come off. Be sure all doors closed. Probably if you have clock, will get a bulb light on pulse every minute or so. This is the electromechanic clock system. don't worry about that.

If you get the inserted bulb light on it does mean this two stuff:
-you have consumption somewhere that never comes off, or
-you have a small short that isn't able to blow a fuse or burn anything instantly, just with long time exposing.
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

lumpy

Thanks Nacho, I had to read that a few times, but I think it will help me track down the short. Anybody else have any experience with this type of problem? I would like to get as much info as possible before I start messing with it. Thanks

Nacho-RT74

sorry if there is some "languaje" missunderstood what makes harder to get... engilsh is not may nature languaje
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

hemihead

Seems to be the typical 3rd Gen problem.My 73 and my son's 73 both have had this problem plus I've seen a lot more of this through the years.
Lots of people talkin' , few of them know
Soul of a woman was created below
  Led Zeppelin

Nacho-RT74

That red wire is THE MAIN KEYED SOURCE on ALL THE CAR, except to the Ashtray, glove box, Map light, Dome light, courtesy light, brakes, hazzards and headlights/parking/cluster since all this stuff is direct batt... they go bad specially on A/C cars and low powered alts. Is the same fail located on bulhead that I have explained on several threads but this time just about Accesories and Run section of wiring. If you don't have a good average charging load, constant high peaks at high rpms will overheat everything.

Now, about this specific topic... does look ore a short than just the tipical overheat.

forgot to say lumpy, bad or "shorted" ammeter will frye even without a key, ammeter has power ALLWAYS. With just plug batt, the melt would start.

As stated, start from basic. Since the first and more badly damaged wire section does look the inside column wire section, start from there. anyway needs to be rewired.

Electric is a very patiente job and can be desesperately stuff if you don't get order on the check.
Venezuelan RT 74 400 4bbl, 727, 8.75 3.23 open. Now stroked with 440 crank and 3.55 SG. Here is the History and how is actually: http://www.dodgecharger.com/forum/index.php/topic,7603.0/all.html
http://www.dodgecharger.com/forum/index.php/topic,25060.0.html

Highway by the Sea

To Lumpy: I registered for this forum for the sole purpose of telling you this.  My Mopar car with identical wiring (73 plymouth satellite) had an "electrical problem" when I bought it.  This turned out to be the entire under hood wiring harness being FRIED TO PIECES!  I found out that someone had stupidly removed the main fusible link, and apparently the alternator grounded out on a piece of metal.  I ended up having to replace the entire wiring harness, because when my mechanic tried to re-insulate the damaged wires, my new electrical points FRIED, my battery "dropped" its cells, and my alternator got so hot that the internal workings melted and fused together.  I had to buy a new wiring harness from a well-known Mopar specialist in my city (only the third one that they had ever sold in ten years), and pay a vehicle wiring expert to rewire everything (including converting it to electrical ignition).  It was worth it!  The car runs great, and all its electrical components work now.  The point of this is to caution you not to just treat the symptom (aka fried wiring) instead of the disease (electrical short).  I hope this helps you.  I made a mistake allowing the first mechanic to attempt to fix the damaged wires, and nearly set my car on fire!  I hope to save you from the same fate.  Good luck!!!!  :2thumbs:

lumpy

Thanks for the info guys. I will start by looking in the steering  column and the ammeter.