I hope... ( EDITED, please check this Canadian 74 Owners ) FINALLY VROOOOM

[Nacho-RT74]

After three months with my car parked starting from this problem:
http://www.dodgecharger.com/forum/index.php/topic,16874.0.html
what it looks IS just damaged DOME BULB, since I removed underdash harness and untapped it to search for short and find NOTHING BUT PERFECT CONDITION WIRES, I hope get it running again tomorrow Sunday. Here is the  story:

Starting from remove cluster to remove underdash harness and get that everything was perfect, then I decided to re-install at this moment the interlock system I removed long time ago because was incomplete on those days. Now is complete to have a complete USA 74 Rallye Charger.

Since I started to have brake problems too and got a new repro prop valve/dist block then I installed and also rebuilt the master cilinder with new pistons and seal kit. At the same time I removed booster to get it refurbished on the original gold galvanized finish.

With parked car then also removed distribuitor to replace bushings and install new collar kit. Also got dist shaft polished.

At the same time I was to install the wiring then decided to add 4 Bosch relays to A/C blower since was melting the fan lever plug and lever itself was gettin extremelly hot. One relay to every speed and another to the Heater speed. All relays after the resistor to keep speeds working.

Now with 4 relays inside the cab, then decided to change the beams Bosch relays to inside the cab to get them all located hidden and no more relays on engine bay what I hate. Also they get lots of corrosion there. Total... 6 relays without wires cut, just removing wires and terminal from original plugs and pluging them directly on relay. Will make diagrams soon about this job.

All relays are being feeded from ammeter stud to get real reading at ammeter with a 14 gauge wire and fuse link to get system protected. No problem on that since anyway max relay working at the same time will be 2... well really three when I change to med or fast speed since low fan speed always is turned on by default when A/C is turned on, but out of load when other speeds are selected ( ohms law ).

Almost all harnesses untapped and retapped with 3M selfducting tape. Still rest 2 or 3 harnesses on all the car to retape. I hate glued tapes. Only harness with untouched tape is the A/C one since still has the non glue factory tape except where I made the relays mods.

Only rest finish some harness job, like on glove box area, some engine bay wires touchs and the undercarpet harness. Also install the cluster.

So tomorrow VRRRROOOOOOOOOM again. I never have prooved the interlock system. Reset button and interlock control are not new, but opened searching for some visible damage and they look perfect. I hope everything will be alright about this.

Funny on all these is that I still haven't located the FIRST PROBLEM posted on link, what started everything LOL, but there are reasons to think on damaged bulb that even never blowed, wasn't brighter as should it be, so probably it has some internal short making a high resistance short able to dim everything on same working net.

[Nacho-RT74]

Ok.. didn't get a Big day... No crank even I have 12 volts at bulkhead yellow wires ( on both ), seatbelt buzzer keeps buzzering even without ignition key on RUN or start position, and seatbelt warning light allways on even with interlock control unit unplugged and without key.

it looks I made something wrong hooking the interlock wires to the underdash harness.

Still don't get how this system works.

[Charger-Bodie]

man that sucks things like that make want dig right in and help but im a hands on kind of help ...damb too bad youre so far away well hopefully someone will chime in and help!!!

[Nacho-RT74]

I'm pretty sure is something stupid... some tied wire bad isolated or kinda, since the interlock stuff I removed at first was hooked on same points I cut. I left a piece of wire when I cut to easy indetification and be sure to join at same points.

Anyway, know how interlock EXACTLY works would it be really helpfull to be sure control unit and reset button are good. Trust me when I say control unit circuit board  and reset button looks perfect condition. In fact 74 Harness I got with all that stuff dId look like NEW.

I WANTED MY CAR RUNNING TODAY.

What is what interlock control unit makes to doesn't start the engine without fastened seatbelts ? engine should at least crank or not even that ?

The worst part is I live in a building on a 6th floor so my car is not at my side, and wiring always ends hurting backs. Usually I work harnesses out of the car but this kind of job really gets me tired removing and installing everytime

[Nacho-RT74]

OK found first mistake... two yellow wires ( one traced ) one to starter relay and the other one to reset button, were turned around... the search keep going...

[twilt]

Good Luck Nacho. Hope you get it figured out soon without too much 

[Nacho-RT74]

OK I don't get it... check the interlock control printed circuit board

Yellow, yellow traced black, Red and Brown wires go to NO WHERE... just end there ( green circles ). In fact, yellow and yellow traced are together on same printed circuit board track... They are already together on spliced point on underdash harness so why here too

Whats the deal ?

Checked part number ( 3501371 ) of interlock unit and states 74 CANADIAN INTERLOCK CONTROL UNIT http://lightningjar.com/decoders/partnumbers/index.php

However Mopar 1974 PN catalog ( april ) doesn't state anything between Canadian and USA parts, just make difference between dates and states for this one: after 02-1-74

Logical, wiring was bought on ebay from a Canadian seller and had everything attached, including control.

Some difference between Canadian and USA models ?

[Nacho-RT74]

OK I checked owners manual and yes there is difference between Canadian and USA models. States STARTER INTERLOCK FEATURE NOT APPLICABLE TO CARS BUILT FOR SALE IN CANADA... so it looks this control only drives the buzzer and warning lights stuff.

IS somebody able to confirm this ?

OK NEW SEARCH... DOES SOMEBODY HAVE AVAILABLE AN USA INTERLOCK CONTROL UNIT ? I need it HURRY!!!

[Nacho-RT74]

OK, finally got the seatbelt buzzer and warning light problem. Seatbelt metalic socket housing was grounding SOMEHOW inside dash pad where map light/seatbelt light insert fits.

This was a headache since I never figured out that, so I started untapping underdash harness, finding NOTHING wrong as I expected after check before untape also with a multitester.

Why I never figured out ? because on that area EVERYTHING is covered with pad vinyl and insert is plastic. Just a small area is metallic, where seatbelt light socket fits. Just released pressure of phillips insert screws and VOILA!!!. Still have to check that ground furtherly but at least is located.

Checked everything else about warning buzzers and everything works perfect... Seat and seatbelts sensors, key in buzzer, and lights on buzzer. Everything is working. So seatbelts control unit is working perfect.

Night did fall down and everything got dark so I still have to figure out the exact problem about crank the engine. Before I removed everything car was running so nothing has to be wrong about that.

Since I find Yellow wires to starter relay and reset button were turned around then IT COULD BE THERE the reason.

Now I would wish about 74 Canadian models how engine harness is... do you have Reset button ? do you have just a plug going nowhere around Ignition Module ? Red plug with two yellow wires, one black and one blue around that area is unexistant ? Does starter relay yellow wire have another yellow wire spliced from there ?

Moderators, be free to move this topic to Gen Tech or Electrical discussion areas.

Whatever, since I discovered I have a Canadian Control Unit that does not work like interlock system and is just a warning signal control, then it means I could get my car running once I save the crank problem no matter if seatbelts are fastened or not but ANYWAY, I WISH TO GET a USA control Unit because that will be a safety system to thiefs. Do you think a thief will fasten seatbelt before stole a car ? LOL.

[Brock Samson]

I'm up here in California rooting for ya'. 

[Charger1973]

See we have it easy, when we have a question we just come here and ask Nacho...  But when Nacho needs help, thats when you know its something tricky!

You know you could always sell it and get a 73 without all that seatbelt interlock stuff.    Good luck man, let us know how it goes!

[Brock Samson]

ya know my road runner has that freakin seatbelt interlock whatchamacallit thing...
It's totally screwed up too, to have to hear that epileptic buzzing, they made it really horribily annoying. Dude, are ya' sure ya' want that thing workin?..
I'll send ya' mine i sure as hell don't want it... original or not... 
my road runner is all about it's seat belts there's eight of the damn things in front three actoss in back too,..
ya know how many damn seat belts that is?....
front shoulder belts too...
i can't wait to get rid of the damn things. 

[Charger1973]

ya know my road runner has that freakin seatbelt interlock whatchamacallit thing...
It's totally screwed up too, to have to hear that epileptic buzzing, they made it really horribily annoying. Dude, are ya' sure ya' want that thing workin?..
I'll send ya' mine i sure as hell don't want it... original or not... 
my road runner is all about it's seat belts there's eight of the damn things in front three actoss in back too,..
ya know how many damn seat belts that is?....
front shoulder belts too...
i can't wait to get rid of the damn things. 

In 74 though, you cant even start your car without puttin on the seatbelt.  My friends 74 Mustang is the same way

[Nacho-RT74]

hehehe, as stated by Charger1973 interlock stuff is only to 74 and 75 models. 71/73 only have warning buzzers and lights controlled separatelly by different buzzer to every function, one to seatbelt, one to key in and one to lights on. Beside that, 71 and I think earliers 72 warning seatbelt LIGHT is time delay flasher controled. On 74 buzzer is the same to alll functions and seatbelt light just turns off when you fasten.

Now about sell 74 and buy 73, sorry I love 74. What can I say ? I like that safety system, specially the three points front seatbelts double retractor. I feel incomplete without fasten seatbelts. Is something that I wanted to learn when I started to drive. I have been involved on a crash car when I was 10 and broke some tooth and my nose in a Nova because I didn't have fastened seatbelts.

Venezuelan Cars didn't have the interlock stuff, they were wired like 72/73 models. Since My 74 Charger was originally standart cluster and changed to Rallye cluster I got a GREAT 74 Rallye underdas harness with allmost all the stuff on just US$25 shipped to Miami. Of course didn't know about USA and Canadian control unit differences on those days.

I cut ( and storaged ) all the "unnecesary" interlock stuff because I had incomplete devices and got My car running fro about 2 years with modified harness, so in case of emergency I can reconvert again to earliers harnesses my actually one ( as it was before this ), but Don't want to. I want to get it working as factory specs.

[Nacho-RT74]

GOOD NEWS... MY BABY GOT VROOOOOOOOOOOOOOOM.

-Didn't crank at first because in fact yellow wires were turned around.
-Also discovered that without control unit engine doesn't crank. Yellow wires are linked inside the control.
-FOUND THE INITIAL FAIL THAT MELTED A SMALL SECTION OF MY FUSE BOX ( link posted at first reply ) and was dimmimg everything... brake pedal switch is somehow damaged and oftenly grounds making fails all around the pink wire net ( hazzards, brakes, map light, dome light, trunk light, key courtesy light ). Still works but I have to check that to fix or change it.
-Confirmed that Canadian control unit just work like a warning buzzers/signals control.
-Still have to check the weird ground inside map light insert. Is fine now but If I slightly press, then buzzer and seatbelt light are activated.
-Still have to bleed brakes.
-Still have to install cluster.
-Still have to make works the relays upgrades but they are ready to play.


Bad stuff are that with all unplugg and plug job, bulkhead engine and headlights harnesses plugs, got broken tabs ( one each ).

So I want to know how exactly are Canadian engine harnesses as stated earlier... wish an USA interlock control unit, and now need new or better engine and headlights harnesses bulkhead plugs. Also wish double ballast resistors plugs.

THAAAAAANKS EVERYBODY

[Charger_Fan]

I love happy endings.

Congrats, Nacho!

[Charger1973]

Good to hear, I might have to come down and get a ride.     Been a while since I got to ride in a 3rd gen.