more harness help please.......

[73-charger-383]

on the firewall of my 73, on the drivers side there are three seperate bulkheads.  the top harness and the bottom outside harness seem to be hooked up correctly, but the bottom inside harness has some problems.  there are two wires (yellow and brown i believe)that go up to the starter relay.--the problem is the other three wires (two black, one black w/a white stripe.).  they aren't connected to anything, except the two solid black are bare ends twisted together. the black/w white stripe isn't connected to anything.  i wasn't too concerned about them, but when the car is running, or in the on position, there is a slight current going between the two solid black wires.--it is also very apparent that at one time the harness with those three wires shorted and burned through the tape.  --any ideas what they should be hooked up to?  (btw, my car was originally a 318, now has a 383).

2#  under the dash there's a connector with the end three wires cut on the outgoing side.  They are two black or brown, and one orange.  --the middle power wire shows where a short occured and had to be cut out of the harness and reconnected.  -the two pins on the inboard side of the harness are open, and an orange wire is in place to hook up to the other orange.--i'll post a picture to better explain.

3#  my temp gauge doesn't work.  i connected the purple wire from the firewall to the temp sender on the water pump housing, and still nothing. (it seems that there are two different sensors, neither work for the gauge) --could something else be wrong, or is my sending unit (s) shot.

thanks guys,
mike

[Chryco Psycho]

ground the wire to the guage , it should move the guage up , if not check for voltage in the wire & trace back to the guage
not sure on the orange wires but usually orange is dash lights 

[Nacho-RT74]

That's the ignition switch plug.

Heavy wires are:
Red, positive input to switch
Black, accesories output ( run and accesories position )
Blue, Engine source output ( run position )
Brown,ballast pypass output to coil  ( start position )
Yellow, Starter relay signal ( Start Position )

The lighter wires are:
Orange, shifter lighining to Column shifter cars. Harness is teh same to all Column and floor shifter cars so harness provide the wire in case.
Black wires are the in and out power to ignition key in buzzer. Drives positive. These wires becomes RED under column. Sensor swicth is with red wires.

Ignition swicthes don't provide this wires since they are already on car ( column ) separatelly so you need to remove from old switch plug and connects on the new ignition swicth plug.

About temp gauge. If you have working rest of gauges then sure the black wire coming from 5 volts voltage limiter on back of cluster is good same as fuse, even wire could it be broken or damaged on that spliced section. Drives positive
Violet wire is of course the sender wire and drives negative. Comes directly from sender on engine. To check gauge conditions, you can plug a 9 volts batt on gauge studs ( remove both wires from gauge studs ) and check if needle moves BECAREFULL JUST ONE OR TWO SECONDS, because that is double of power that is able to drive... that will gives power to check if needle moves and will mean gauge is good. Then if moves, you probably have bad sender

[Nacho-RT74]

on the firewall of my 73, on the drivers side there are three seperate bulkheads.  the top harness and the bottom outside harness seem to be hooked up correctly, but the bottom inside harness has some problems.  there are two wires (yellow and brown i believe)that go up to the starter relay.--the problem is the other three wires (two black, one black w/a white stripe.).  they aren't connected to anything, except the two solid black are bare ends twisted together. the black/w white stripe isn't connected to anything.  i wasn't too concerned about them, but when the car is running, or in the on position, there is a slight current going between the two solid black wires.--it is also very apparent that at one time the harness with those three wires shorted and burned through the tape.  --any ideas what they should be hooked up to?  (btw, my car was originally a 318, now has a 383).

Main bulkhead harness provides sources to 4 harness, not 3. The outer big ones are, front lighning and engine harnesses. The upper inner one is wiper motor, and the bottom inner is the Neutral Safety Switcn coming from tranny. I don't know why some of these harnesses have a brown conected on that plug on cars earliers than 74, but that plug it should drive only 2 black wires even harness drives three wires, adding a brown wire that doesn't arrive to plug.

the brown wire comes from center pin of NSS and provides ground to starter relay on P and N shifter and is just one wire from NSS to starter. On 74 I think this wire is spliced to the plug to give a source inside the cab because Interlock seatbelt system use/needs that signal.

The black wires come from the outer pins of NSS and is an IN and OUT source to feed the back up lamps. The NSS drives beside the ground safety also the swicth on on reverse. Inside the cab ( back of bulkhead ) they are white and white traced black wires. Doesn't really matter wich wire si plugged where, since you need just an in and out. Those wires drives positive.

The two empty cavities on that plug should it be blue and green wires to compressor clutch and A/C blower on A/C cars. since 74, those two wires are out of bulkhead, throught a grommet on firewall, since as explained those cavities are used to Interlock system with a  brown and I think yellow wire to Reset button ( don't remmeber exactly )

[73-charger-383]

great ......everything is making sense finally.........

i've only got one more question.
under my dash, in the group of wires going to the back of the instrument cluster, there's a grey wire that is cut.  It has power with the key.--where should that go........oh yeah, and that orange wire is the shift indictator light like you said, but i'm having trouble finding the wire to source the power for it.  I can't find any wire that is "open" that comes live with the headlights........or should the shift indicator light be constant with the key......

thanks nacho

[Nacho-RT74]

The orange wire what is COMING from the underdash harness and is spliced from same wires that lights on the cluster, so it should be lighten on only when you have cluster lighted on. Column should have the ORANGE wire and socket with bulb bolted inside the column. Is a separated wire from the rest that must be located on ignition switch plug cavity, same separated as key in buzzer switch with red wires.

Cars with ignition key courtesy light uses a separated yellow wire with female spade terminal that plugs on a provided male plug with also same yellow wire on underdash harness and is linked and works with a time delay flasher ( if your car is equipped ).

Some IGNITION SWITCH harnesses ( the one coming from column ) have an extra lighter black wire on cavity where supposelly plugs the shifter light ( I DON'T KNOW WHY THE HELL ). I think that is an extra accesories source, not sure about that. Only sure is that if you will need to remove that wire, if that is the case and install on that cavity the orange shifter light wire. Cars with floor shifter also nees to remove that wire because when you turn on the ignition switch, then will have cluster lighted on ALLWAYS throught this wire.

Gray wire I found is one with 90º degrees bullet female terminal it should be Oil sender source to gauge and drives negative not positive.

Only wire that have constant positive power once you trun on the ignition switch is a black one with female terminal that plugs on cluster voltage limiter.

I guess we are talking about a rallye cluster.

NOTE APPART: I have noticed recently on a 73 diagram that underdash harness also has a brown traced yellow wire comung from tranny bulk that is used on some related seatbelt system, so probably your one it should have also a brown wire arriving on tranny harness plug on bulkhead spliced from wire coming from tranny NSS ground, maybe spliced from the starter brown plug and  maybe to make works the seatbelt buzzer and light warning system. If so, then A/C wires ( blue and green ) are somewhere on firewall with a grommet same as 74s