harness fire...

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MoPowAR

MoPowAR

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So Im a brand new MOPAR guy, just bought my first one last week...74 Duster with a built 360!!!
Unfortunately it caught on fire on the drive home! Was driving back and stopped for gas, noticed smoke, opened hood, saw flames, put it out quick... it was small, engine bay side only, main power lead goin through the fire wall. Towed it home and replaced the engine harness, and the main bulk head connector, both sides..

Checked the dash harness, just the main power lead going to the amp gauge fried, replaced it.

just got a new ballast resistor, (it did the whole I'll only run with the key in the start position thing).

But I fear there is a short somewhere else. When I was trying to keep it running, i blew the fuse on the main power coming in (aftermarket fuse able link on engine bay side). from what ive seen here looks like it could be a worn/shorted run position contact on the ignition possibly too. havent opened up the ignition column to check yet though.

I am also trying to see if there is a better way to run the main "hot" line coming in through the fire wall to the main input on the harness, instead of going through the amp gauge on the cluster???
 
The cheap plastic insulation in ALL vehicles has a tendency to melt and weld other wires in the harness to adjacent wires. It can make a mess. I recomment you inspect the harnesses carefully, untape them if necessary to be sure there are none of this.

Old Mopars are TERRIBLY underfused. By that I mean "not well enough protected."

In my younger days, a young lady mashed up my 70 RR While it was in the shop, I had a loaner car that suffered a dead short in the alternator. I sat right there and watched the under-hood harness go psslsllfffffssssfffftttt!!! and then blow the fuse link.

Called the dealer. Said "send a wrecker, and another loaner car."

So they sent a pickup truck with a set of booster cables. Driver says "we're gonna need a tow truck and another loaner car!!"
 
so updates....

i had completely unwrapped the dash side harness and checked for melts/shorts in the system. no sign of damage (other than the fried amp gauge wire i replaced) then i wrapped it all back up. I havent been in the ignition column yet though...

i also bypassed the factory power entry points through the connectors in the firewall. I ran power like in the link to the mad elec guys page... Independent 8gauge power cable from the battery with an inline agu fuse. I spliced it to the "top" side of the main power distribution in the dash (black wire going into amp gauge). Then I spliced into the bottom side lead that heads out the firewall to the alternator. I put the slice on the dash side and ran another dedicated power line to the same fuse going back to the battery. Then I ran a direct 8 gauge power cable from the positive terminal on the battery to the output stud on the alternator.
system now looks like this...

http://www.madelectrical.com/electricaltech/images/amp-ga27.jpg

According to theory this should all be fine and dandy, no more amp gauge in the dash and new, heavy, fused lines handling the power transfer... except...

I cranked it over a couple times, pump gas, didnt start, let off...
cranked it again a couple times, started running and i saw sparks coming from the alternator for a moment. I have no clue why??? could a shorted alternator perhaps have caused the fuselink to burn up, causing my harness fire initially???

I also noticed it still wouldnt stay running with the key in the run position, only while cranking in start position... Just put a new ballast in...

So im currently at... why the sparks from the alt???
and, is there a short/malfunction in the ignition column???

any thoughts would be greatly appreciated guys...thanx.
 
un hooked the alternator from the system entirely, and put a charger on the battery then tried to start it...

still does the thing where it will run if i hold the key in the forward "start" position, wont stay running if I let it spring back to the "run" position.

i am going to pick up another ballast resistor tomorrow to see if the problem goes away... if so i believe it would have been caused by the alternator shorting out...which caused the fire the first time???

if i put another ballast in and it still doesnt want to stay running with no alternator in the system, then... fried ignition column harness/cylinder???

but why would a bad ignition column cause sparks from the alternator???
 
also... I didnt think it would be the alternator because it looks like its newer and not original...but sparks from it. Like you said 67dart, dead short and harness goes pff.... new alternator now??? maybe ignition cylinder and/or wiring??? Looks like I gotta go tear into that ignition column now, i dont want to mess with it though, not sure how to pull it apart....more research needed...
 
one last thing for tonight...

so i noticed while poking around that on the new harness there is a grey wire with a female spade (non insulated) on it by the ignition wires on the passenger side of the harness in the engine bay. I did not know where to terminate this when installing the new harness because there wasnt anything similar on the old one. i wired it up the same way the mallory ignition box was wired before... dunno what this grey wire is for???
 
I believe the grey might be your oil sender.

It is not very difficult to tear down those alternators, you might do that and inspect it.

You have a shop manual/ wiring diagrams?

You should be able to unhook the alternator and 'safe off' the wiring and run the car just on the battery for testing.

Sparks in the alternator--should not be. Now, it could be either way......if there is some short in the system, the alternator could be sparking internally because it burned up something in there, diode, winding, etc trying to "keep up" with the short, or it could be the other way around......the alternator could have a serious problem and could BE the short to start with.
 
updates...

i unhooked the alternator from the system and unplugged the ignition cylinder from the harness on the steering column...

I "hotwired" the car by jumping the power wire on the ignition harness (dash side not key side) to the ignition 1 and 2, then i jumped over to the start wire momentarily. it started right up and ran great this way, i also had power to all terminals on my ballast resistor too...
so i know the ignition switch on the column is fried...have to replace/repair that...dont even know where to start there. thats first.

I also jumped it with the alternator hooked up to the system... no sparks from it, but it also wasnt outputting any power. I put my voltmeter on the battery while running and it went from 12.6volts when sitting to 12.5v and dropping as it ran.
so i pulled the alternator off and disassembled it. i fried a little diode or something in it, not sure what, i dont know much about alternator design. its a small cylinder with a single wire coming out that grounds to the housing...need to replace it somehow... alternator has a part sticker on it that says prostart 7014. ill start my search there.


TO DO;
1) repair the alternator, should take care of my charging issue.
2) repair the ignition cylinder, should take care of my short (hopefully)

it appears that the "run" position contact is fried, not allowing it to run with the key in normal operation. i would think i could rebuild the wiring on the cylinder if its not too bad. i have to tear into it and pull it off first. does anyone know if there are any ignition cylinder repair kits out there?
 
I dont know of a rebuild kit for those switches.
Considering the labor involved in getting to the ignition switch I would replace it.
I put a new aftermarket switch in my 73 about 4 months before I parked the car.
PM me if interested.
 
You checked the "crank hot" brown
And the "run hot" blue? At the column plug and both sides of bulkhead?
 
so i took the alternator to a shop, pulled it apart... fried diodes and such. so i got my hands on a chrysler 100 amp alternator, having it refurbed. should be ready tomorrow. im going to have to fab some new brackets to hold it...

i got an ignition switch from the local napa today too. price wasnt too bad.its was nice that i could just go pick it up. took care of my issue with the no run in run position deal.

except it is not fully installed. i have the column pulled apart, following the manuals instructions. couldnt locate the steering wheel lock plate removal tool though. ive checked the other threads and the information was helpful, except no one said if they got that tool from the dealer or what. local autozone and such dont have that tool. i fear when i check the dealer tomorrow IF they have it, it will cost more than i can handle at the moment....

are there any other ways to get that pin out of the steering column shaft??? the manual says not to hammer the pin out with a punch. i assume this is because it will warp the shaft and/or deform the shaft bearings???

im dead in the water till i get this plate off...
 
MoPowAR said:
so i took the alternator to a shop, pulled it apart... fried diodes and such. so i got my hands on a chrysler 100 amp alternator, having it refurbed. should be ready tomorrow. im going to have to fab some new brackets to hold it...

i got an ignition switch from the local napa today too. price wasnt too bad.its was nice that i could just go pick it up. took care of my issue with the no run in run position deal.

except it is not fully installed. i have the column pulled apart, following the manuals instructions. couldnt locate the steering wheel lock plate removal tool though. ive checked the other threads and the information was helpful, except no one said if they got that tool from the dealer or what. local autozone and such dont have that tool. i fear when i check the dealer tomorrow IF they have it, it will cost more than i can handle at the moment....

are there any other ways to get that pin out of the steering column shaft??? the manual says not to hammer the pin out with a punch. i assume this is because it will warp the shaft and/or deform the shaft bearings???

im dead in the water till i get this plate off...
Click to expand...

At least one of your local parts stores can get you a lock plate removal tool.
otc-7031a_w.jpg

I think I got mine from the local snap on dealer.
Also what pin are you wanting to drive out?
~Michael
 
The pin crossways through the top of the shaft is tapered. It will go out and back in only one way. With the wheel centered the pin will go out toward the drivers door window. Broken glass and damaging the pizzy little upper bearing is why they say dont drive it out. Most do anyway. Put the steering wheel on and use it to support the shaft.
All the lock plate removal tool does is overtake a strong spring under the plate. It pushes the plate down so the snap ring can expand out of the groove in the shaft.
I conquer that by hand too. The trick is to push the plate down and pull the shaft up at the same time. If you have a steering wheel puller, a couple of spacers between it and the plate will work too. The spacers will need to leave room for you to get the ring with a dental pick. Hope this helps
 
so i got the steering column fully disassembled and installed the new switch. tahnks a ton for the insight guys, i hit the pin with a punch and it shot right out. i went to run some tests and it started doing the same thing the old switch did. would start but looses power when the key springs back to the run position??? i am baffled by this.

the ballast resistor shows no power when the key is turned on. but if i jump the ignition harness (dash side where the ignition switch plugs in), i can start it and it runs fine, power on all ballast posts... i have a short somewhere else apparently? the brown ignition 2 wire has no continuity on run, but the ignition 1 and accessory blue and black wires do. if i simply "jump" power from the red hot wire to the ignition 2 wire next to it, then temporarily jump power to the yellow starter wire and then remove it, the car will start and stay running...

i noticed that just after a minute of running the stock electronic ignition box on the driver fender wall was noticeably warm... i'm wondering if there is an issue with the ignition system to blame. the car has a really old mallory ignition coil and it feels like an old battery low on acid. when i took it of to wire the new harness i noticed i could hear fluid moving inside it when i rotated it on its side. sounded like it was half empty. is this normal or a trouble sign? i dont know these aftermarket ignition coil systems...

has anyone ever heard of a coil frying the ignition system??? i dont know where to go at this point. the wires from the ignition switch to the bulkhead are good. the wires in the engine bay are in a new harness... somehow it fried the alternator too, so something is screwy in there. i am quite confident that the dash side of the wiring is ok as it is 99% stock at this point. 100% referring to ignition(factory ignition switch in factory harness going into bulkhead).

does anyone have ANY insight or ideas? i am at a brick wall here and not sure where to turn....

thnx.
 
some new developments...

so just to humor myself i picked up another ballast resistor, new out the box it had the same resistance values that the one currently on the fire wall had. i even plugged it in and tried to start the car, no dice. same issue as before, would start then die with key in run position.

so i plugged the other ballast in, unplugged the ignition switch, and jump power to the brown ignition 2 wire on the dash harness. car started right up like it has been.

[ame="http://www.flickr.com/photos/34576848@N06/6242627146/"]IMAG0130 | Flickr - Photo Sharing!@@AMEPARAM@@http://farm7.static.flickr.com/6101/6242627146_22e8ccc853_m.jpg@@AMEPARAM@@6242627146@@AMEPARAM@@22e8ccc853[/ame]


I went to touch the factory ecu box to see if it was getting warm. it was, significantly in only a matter of seconds! i touched the gold colored heat sink and it shocked the hell out of my hand!--------what would cause this to happen? is this box grounded through its mounting point on the fender wall? i ask because the fenders on my car are fiberglass and that will not work if so...

[ame="http://www.flickr.com/photos/34576848@N06/6242627142/"]IMAG0131 | Flickr - Photo Sharing!@@AMEPARAM@@http://farm7.static.flickr.com/6231/6242627142_627e16d100_m.jpg@@AMEPARAM@@6242627142@@AMEPARAM@@627e16d100[/ame]

i am almost certain that there is some issue in the way the ignition system is wired up if this box is ok and not shorted internally....
Under normal starting conditions (with the key turning to start) it will start up, but as soon as i let the key spring back to run it dies. the ignition switch is supping power to the blue and black ignition 1 and accessory wires in the "run" position. in the "start" position, the switch is sending power to the yellow and brown, start and ignition 2 wires...which allows the ignition system to fire and the engine to start up.

so.... that means that the engine will run with power to the brown ignition 2 wire, which is what i "jumped" power to, from the red 12v wire to "hot wire" the car. under this condition it started and ran fine... except for the control unit on the fender wall. it shocked me, obviously there is a short in this loop. what is going on?!?! any insight is extremely helpful guys...
 
The ignition module shouldn't shock you. I does require a chassis ground and should be grounded before connecting power. I dont know what method of ground would suit me on a fiberglass fender. I would probably just mount it on the firewall to eleminate the concern.
Factors like those fenders can't be seen from here :(
 
well im wondering if the ignition module shocked me because i had a jumper on the brown ignition 2 wire (which normally doesnt have current flowing after start up)??? could supplying current through that wire temporarily "short" the module?

i will definitely put a dedicated ground strap on that module though just in case and see if there is any effect on the system....
 
so i put a dedicated ground in the ignition ecu, no change. i think the shock was just because i was suppling power to the brown ignition 2 wire while it was running.

still will only fire in "run" position, then dies....i have no idea what the hell to do....

does anyone know of any mopar shops in phoenix, az area???? cant find one...,
 
Grounding a bad ECM after the fact isn't going to cure it. Pictures might help.
 
RedFish said:
Grounding a bad ECM after the fact isn't going to cure it. Pictures might help.
Click to expand...

right, but the car was running and driving fine before the fire with no other dedicated ground on the ecm... not really sure about how it was all set up though. I cant find an ecm online...gunna have to start calling around.

also, no one really said if they though a bad ecm would allow the engine to start up when cranking but die on run conditions????

(if you click on the link in those purple boxes above, it will send you to pics of it on my flickr page)
 
MoPowAR said:
right, but the car was running and driving fine before the fire with no other dedicated ground on the ecm... not really sure about how it was all set up though. I cant find an ecm online...gunna have to start calling around.

also, no one really said if they though a bad ecm would allow the engine to start up when cranking but die on run conditions????

(if you click on the link in those purple boxes above, it will send you to pics of it on my flickr page)
Click to expand...

OK , I did see a pic of a dual ballast resistor. The original factory connectors were keyed so they cant be attached wrong. if you have a later edition revised ecm that has only 4 contact pins you need only a single ballast resistor. A dual ballast resistor can do more harm than good in a homemade setup simply because it could be hooked up wrong.
 
OK....

i had to take some time away from the car to get my bearings. my Chrysler 100 amp alt was a no go as the pulley was seized to the shaft and the shop cracked it. so i had them build me a 100amp, internally regulated delco unit. i made some brackets and got that sucker on there with a single output cable goin direct to the batt.

i went back to square one and kept note of trouble shooting basics. after a while i found that the dash side was ok, i was getting power through the firewall on all ignition circuits... after some more diagnostics i determined there was no continuity between the bulk head connection and the terminal on the ballast resistor, the ignition1 (blu/whit) wire. dont know how the hell i missed this, the fact that it was a new harness probly!

so i tear open the new and freshly wrapped up harness. sure enough there was a break in the ignition wire from a bad splice!!!!! i soldered the connection back together, buttoned up the engine bay and the dash.... now she starts right up and runs beautify. excellent throttle response on the engine and she's runnin nice and cool for me. I am very excited to have the car in one piece.

I beat the electrical fire that ignited on day one almost a month ago!!!! My mopar now boast a brand new wiring system as well as a 100amp output and dedicated heavy duty 8gauge cables for the power system. shes ready for any and everything electrical i can throw at her! cant wait to do a cool custom gauge bezel setup... also, I called the shop who made the harness for me and they kicked me some cash back to resolve the issue.

Now i have to get that ol 727 3 speed adjusted up so she will shift properly and Im ready for the road!!!!

Thank you to everyone for the advice, resource information and moral boost! it got me through this nightmare.

Consider this thread complete!
 
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