73' Charger Toasted Fuse Block & Wires you have to see this ! Help !

[BMOTOXSTAR]

Nacho,

Thanks man !

I was just about to start...so use the butt connector crimp & no solder?
 

[Nacho-RT74]

oh well, solder it with the connector, but not red wire straight with fuse link. sure a straight splice is better, but when fuse link is gone, will be hard to service and the best is get the best of both worlds... good conection and "serviceablity"

[BMOTOXSTAR]

Soldering is a real art ! Sticking with the butt connector & shrink tubing. Not that many pieces to splice & I have plenty of wire and fuse-links in the tool box now !


Nacho, I would be lost on this without your help & diagrams. Thank you mane !
If there was a joint smoking emoji I would post that also !

[Nacho-RT74]

factory never soldered the wires and terminals, just crimped, but sure factory tools and skills are better than any ppl who doesn't use to deal with this stuff, so soldering is an extra safety point to be sure wire won't leave the terminal accidentally and assure a better contact.

[Jonas_N]

Great thread. Im doing the same mod now when installing new wiring/gauges in my car.

One thing I made to make the ammeter more secure was to add a fiber board (used for printed circuit boards) both on the inside of the housing and a large piece on the outside, I also put shrink tubing on the studs where they pass through the gauge housing.
(I checked and the Am-meter needle still has about 1.5mm of space in front to move around freely.)

[Nacho-RT74]

cool!

[RallyeMike]

Thanks for posting this cup Nacho! I know it takes some work. You are the man - saved them for future reference 

[Nacho-RT74]

It's a pleasure

Some of the diagrams I made are already posted and explained on the stickied thread about charging system upgrade

[BMOTOXSTAR]

Nacho...I get her all back together and this...turn the key and no power to starter solenoid. Does start when jumped at relay, as usual. Turns off when key is turned off. AMP reads towards  "D".

Looks like this aftermarket ignition swatch is missing 2 wires than the original?

Man this is frustrating....and the Brake light stays on and the fluid, etc are good.

Nacho...what do you advise?

[Nacho-RT74]

The two wires missed are the red ones from ign switch sensor to warning buzzer. They connect with the two thin wires on underdash harness plug. In no particular order.




Remove the thin black wire from the new ign switch harness which is meeting with the orange at underdash harness. As far I know thats a ground signal used on some laters cars ( for whatever reason I still don't know ). If that's true you could short out the cluster dimmer circuit ( orange wire ) when you turn on lights. Nothing really dangerous, but just will get a fuse blowing up. The orange wire is there just to feed the shifter gear indicator on steering column cars. Floor shifter cars doesn't get a wire there into the ign switch and orange line just ends there

About the fail... have you checked if bulkhead wiring dispositon meets with your engine bay side harnesses? Are you sure the underdahs harness is 73? Along 71/74 some wires where turned around.

Brake light... I guess you mean the brake light on cluster. That light turns on when emergency brake is activated or you have a pressure failure on brakes system. Sensor is on brake fluid distributor. Both drives negative. It could be any or both wires shorted to ground... or simply working and its indicating the emergency brake is applied or you have some brake fluid pressure failure LOL.

On my car I had the brakes dist block damaged and that kept on the brake light on cluster.

OOOOR also related to a wires turned around on bulkhead ( if is not 73 harness ). 72 and 73 are pretty much the same harness except for some extra accesories feeds and the headlight concelead light trigger provision, both on 72 harnesses. I think the driver door jam switch setup changes. But still some wires could be turned around on bulkhead.

71 and 74 underdash harnesses are way diff monsters between them and with 72/73

[BMOTOXSTAR]

Nacho,
   I am for sure it is 73' Harness, all plugs and wires matched up perfect and the vacuum lines for the AC were right on as well.

I do have a small brake leak due to a master cylinder I need to fix next.

So, take that black wire off the new ignition switch and make sure engine side to bulkhead are plugged in correct...

Thank you Nacho.

Hope the next post is that she started !

[BMOTOXSTAR]

So I have checked all connections at bulkhead. All Good.

No power on volt meter to starter relay on the starter selonid tab. All other contacts on starter relay have power when key is in start / run position.

So I figure next step is starter relay since no power to starter from relay and or ignition switch?

I took the black extra wire of that you said on the ignition switch harness end.

[Nacho-RT74]

if you are getting power on yellow wire trying to crank problem is either relay or ground from NSS at transmission. You can ground the G terminal on relay to check if cranks up. If does, problem is related to NSS or harness.

[AKcharger]

I like that color wire diagram...was playing with my dash last week

[Nacho-RT74]

LOL



The color diagram works for 72, except for some details.

[BMOTOXSTAR]

A good album by GN'R btw ! 

As you said, I went and doubled checked the engine side bulk head. I find this....wow....this explains it.

ALT ground wire on engine harness...so the ignition switch will not ground either & I am lucky I did not burn this new bulkhead....I did not run the thicker ground only the AMP+ upgrade.

Nacho, this would also cause the gauges , oil pressure, fuel, etc not to work due to the fried ground?

[Nacho-RT74]

If you meant the black thick wire coming out from alt... is not ground but positive. The alt feeds ground throught the chassis, and gets a negative regulated field straight from regulator on the green wire. Ammeter gets positive on both sides, but senses the electrons magnetic field sense coming and going. They are labeled as red and black just to be sure you'll get a correct reading and not reversed on the way the load goes and comes from/to batt/alt.

What you show is the tipical bulkhead alternator melt due the excess of load on alternator wire and terminals caused by the poor charge capacity at iddle which makes to give back the load to the batt for loooong time periods ( and high load peaks )when reving up the engine, hence the reason to upgrade alternator first for a better average load source, then the paths.

About the wires on harness. Who knows which wires are affected around and could cause misterious failures.

However still without that wire, the engine should crank and everthing should work but with a discharge reading on ammeter. If the ammeter is conected, the batt will source the ign switch then the starter relay. Of course that wire hanging around and without cover is dangerous because if regulator and alt fields are connected, with engine on that wire will be hot from alt.

Check that wire from end to end. Yes, you'll need to get it deeper into your wiring.

P.S.: I'm actually not a big fan of G'n'R LOL.

[BMOTOXSTAR]

Replaced that wire and did more trouble shooting.

It was the NSS wire ! I did the ground on the relay and she starts Nacho !!!  

The radio is not in so I can touch the termianls on the AMP Meter, nice and cold, no resistance.


Only 2 problems,

1. No cluster gauges work (oil, fuel,temp.) All cluster lights work,

2. Turn signals do not work on side markers. Blink on the cluster and fender and work on the taillights.



Nacho...I am almost there.....please advise.

[Nacho-RT74]

-sidemarkers don't blink, they are just position lights for the cars around you. They turn on with front and rear parking lights. They can be made to blink with some wiring mods thought.

-Gauges not working...this is the dangerous ( to the pocket ) part LOL. All 3 gauges are feeded from voltage limiter. The voltage limiter works with a pulsating signal made with points inside, getting 12v positive ( in ACC and RUN ) throught a black wire straight to one of his backelite prongs, to feed with 5 volts to the gauges ( produced by this pulsating signal ) to the ouput to gauges. Bracket gets another black wire with a bigger terminal to not get confused with the positive one to reinforce the ground it gets through the chassis. Ground is REALLY important on the VL because if it doesn't get ground the points will remain closed allowing to pass the 12 volts and burn all the gauges.

since you don't have the Radio yet you still have access to the limiter. Check the correct conections ( diagrams shows how they must be wired ) to the VL

you could also check if gauges are still in working order. Any 5 volts DC source ( or close ) around will work to test if gauge needles move. You could use a cell phone charger, 2 1.5V batteries in series, or even a 9 volts battery but this could be dangerous if you don't remove it quick, because a 9 volts batt can burn gauges too if gauges are sourced for more than 2-3 seconds. This is to check JUST if gauges are live. Jus feed every stud of gauges with the batteries poles ( no matter which one where ) and needle should move.

you can check also the VL conditions with a test light OR analog multitester in DC. Feed 12V and ground and checking the output for this pulsating signal.

of course also check the positive source to the VL to check if is getting juice.

[BMOTOXSTAR]

Yeah Nacho...they worked great until I did the wiring !

The limiter is the block on the back of the cluster with the prongs correct? I hope just the voltage regulator  for the cluster blew out?

There was no smoke, just dead gauges.

[Nacho-RT74]

Yes... that block with prongs.


No one of the parts involved will smoke. They just die, and done

[BMOTOXSTAR]

Nacho, this is what the local parts store had and I have the other style that is on the OEM box pic.

How could there be 2 very different ones for that cluster?

Turns out that the cluster gauges are fine ! I did not have the + connector hooked up to the voltage limiter prong ! 

Nacho many many thanks and an ice cold Tecate ! 

I found a thread you did in 2015 on another forum, forbbodiesonly.


One last question...I lost the floor shifter indicator lights...is this into a port on the passenger side kick panel?

[BMOTOXSTAR]

For the 30 years I have owned 3rd gens I never knew that about the side markers not blinking... Nacho...wow....

You are the man !

[Nacho-RT74]

On 3rd gens there is a diff limiter between standard and rallye cluster. The first one is for standard cluster, second one for Rallye.

I'm on FBBO board too.

Yes, the console light wire gets two wire sections, one from driver side feed on dash harness ( bullet terminal ) up to passsenger kick panel ( spade packard terminal ) , and the next from there up to console.

Be sure you conect positive ( prong on bakelite ) and negative ( prong on bracket ) wires to the limiter please.

[BMOTOXSTAR]

Having trouble finding the black/white trace with with connector for the extra ground.

If it was missing could I make one and ground to the chassis?

Many thanks man