Ez wiring help

[Mr.Hyde]

It looks like one of the terminals is broken off terminal 4 to be exact. I guess that power out to wiper terminal...

[ray_mcavoy]

Originally Posted by Mr.Hyde

It looks like one of the terminals is broken off terminal 4 to be exact. I guess that power out to wiper terminal...

Oops! I forgot to mention that not all wiper motors have that #4 terminal to pass power on to the washer pump.

On motors without it, just run your +12V feed wire to the "(2) Power" terminal as usual and branch off from that with a second short jumper wire over to the washer.

[Mr.Hyde]

Ha all good sound good I was scratching my head while trying to see where it might be broken I'm just hoping everything works once I'm done I don't see any wires to run to that plug on the steering column tho according to the ez wiring diagram just runs straight back and to the column plug for signals emergency etc

[Mr.Hyde]

So on the plug for the dash I'm left with the 1,3,8,12 terminals in still unsure about what these are. Still figuring out the ignition switch. Will be wiring the wiper and heater today hopefully. There's nothing that goes to the back up switch... And I need to find a way to run power to my dome light.

[Mr.Hyde]

So if I understand this right the 3 terminal will get the red power to cluster wire from the harness

The sending unit which I guess is pink will run to the 4 terminal

The brown instrument panel light runs to the grey for the heater lamp from the heater lamp to the cluster.

And I'm just going to cap off the ammeter wires I think...

[Mr.Hyde]

Also seems like I maybe adding another small fuse block

[ray_mcavoy]

Originally Posted by Mr.Hyde

So if I understand this right the 3 terminal will get the red power to cluster wire from the harness

The sending unit which I guess is pink will run to the 4 terminal

The brown instrument panel light runs to the grey for the heater lamp from the heater lamp to the cluster.

And I'm just going to cap off the ammeter wires I think...

I'm not familiar with the EZ wiring color codes, but the #3 terminal on the cluster plug should be fed by a power wire that is switched on & off via the ignition switch. If that's the case with the red wire in your harness, you should be all set there.

Yes, the wire that runs from the fuel sending unit goes to terminal #4 on the cluster plug.

Assuming EZ wire is using brown for the instrument panel light circuit, yes you'd run that wire to the heater control lamp and to the cluster connector's #8 terminal.

As I mentioned in my earlier reply to 72ChevyMan1 in this thread, the EZ wire harness might not have the charging system configured in a manner that will make it easy to hook up the stock ammeter. So just capping off (or removing) those wires off is probably a good idea. And you might want to check with TBone1964 about getting a voltmeter that will fit in place of the ammeter. The voltmeter wiring can simply tap into the temperature gauge's existing power & ground connections so it's easy to hook up.

[Mr.Hyde]

I'll probably just buy an aftermarket one I can mount under the dash at some point. Red is described as gauge power according to the wiring diagram provided.

[Mr.Hyde]

So now I need to get my ignition switch figured out. On the color coded diagram I notice the brown and brown/white wire run to the same place on the fuse block. Temp guage and brake warning are run through which I'm guessing is the acc side of the switch. The coil ign and bat term all are just direct to. Am I correct in saying this?

[Mr.Hyde]

So looking at the wiring diagram again for the dome light now, it looks like my truck didn't come with door jamb switches I'm wonder if I run this instead of going to the switch would I run power off the same fuse the brake switch and headlight switch are run off of? Bypassing the door jamb switch?

[72ChevyMan1]

Originally Posted by ray_mcavoy

You have the full-gauge "7-hole" style instrument panel, correct? If so, the pin-out of the connector is:

Cavity # / Stock Wire Color / Function
1 / black with white stripe / ammeter (alternator side)
2 / tan with black stripe / brake warning light
3 / pink / +12V switched via ignition
4 / tan / fuel gauge sender
5 / empty
6 / dark green / temp gauge sender
7 / black / ground
8 / gray / cluster illumination
9 / dark blue / right turn indicator
10 / light blue / left turn indicator
11 / light green / high beam indicator
12 / black / ammeter (battery side)

The cavity numbers are molded into the plastic on the sides of the plug.

Most universal wiring harnesses probably won't have the provisions for the stock battery gauge (ammeter) wires that go to cavities #1 and #12. And the harness probably won't have the alternator output and main feed wires configured in such a manner to work with the stock battery gauge either. The easiest way to deal with that would probably be to convert to a voltmeter. Check with member TBone1964 ... he sells 76+ voltmeters that are modified to fit 67-72 gauge clusters.

I am a little confused. Reason being is I have found different diagrams that do not have the same Colors as my plug. I do not have a tach so I only have 6 holes on my cluster. Does that make a difference? If not do I still use the quoted reference to wires?

[Mr.Hyde]

What is your color code? Mine is no tach and matches the diagrams

[Mr.Hyde]

Ok so I'm working on the ignition switch now which is pretty much the last of the dash except the dome light getting wired in and I'm looking at my diagrams and the only one I can't figure out is the brown/white wire from the ignition switch not sure what that wire is about? Also the harness from ez has a black wire splices from the (red) ignition switch power, not sure what this is.

[VetteVet]

Originally Posted by Mr.Hyde

Ok so I'm working on the ignition switch now which is pretty much the last of the dash except the dome light getting wired in and I'm looking at my diagrams and the only one I can't figure out is the brown/white wire from the ignition switch not sure what that wire is about? Also the harness from ez has a black wire splices from the (red) ignition switch power, not sure what this is.

The brown/white wire from the ignition switch is usually wired on the same terminal as the 12 gauge brown accessory wire. It is a small gauge wire and it is a resistance wire which runs from the key switch to the inside of the firewall block where it joins with the 16 gauge brown solid wire on the engine side of the block and runs to the external voltage regulator. If you or someone has converted the alternator to an internally regulated SI or CS then this is the wire that feeds the excitation terminal on the internally regulated alternator. It may be splice to the white wire in the EVR plug and run to terminal one on the alternator, or it may go straight to the alternator and have a resistor in-line connected to the L terminal on a CS style alternator.

This is how the key is wired. The black arrow to the left is the brown wire to accessory and the wire just below it is brown/white stripe wire. I do not know of a black wire spliced in with the red power wire. Black is usually designated as a ground wire and it certainly wouldn't be connected with a red power wire.



Here is the cluster connector for the gauge dash. it shows the stock wire colors and tells what terminal they go to and where they come from.
They may be different from the EZ harness you have.

[Mr.Hyde]

So is this a deletable wire then I have external rectifier. And any info on the reverse lights I done see a connector or plug on the trans

[VetteVet]

Originally Posted by Mr.Hyde

So is this a deletable wire then I have external rectifier. And any info on the reverse lights I done see a connector or plug on the trans

The brown/white stripe wire must not be deleted, unless you can run a key on power wire to the alternator,with a resistor wired in series in the wire. The factory used the B/W stripe wire because it's a resistor wire equal to 10, ohms for the factory externally regulated alternators. The charging light on the idiot light clusters serves the same purpose along with providing an indication of charging and battery status. We can get into this more when you're ready to wire up the alternator.

I don't know what you mean by (external rectifier) unless you mean the external voltage regulator mounted on the radiator support by the left headlight.


Here is some info on the switch,
https://www.google.com/webhp?sourcei...+switch&spell=

Your reverse lights are a simple circuit . You should have a fuse on the fuse panel that says reverse or back-up with a 10 ohm fuse, IIRC. There should be a dark green wire running from it to the switch on the transmission and a lighter green wire from the switch to the rear of the truck to the back-up lights. I had to search your build thread to be sure you had a standard transmission. Do us a favor and revise your signature to include more information, or at least put it in your thread.

I can't be sure what b/U light switch you are supposed to have because there are quite a few. It should mount near the linkage for reverse in a port on the trans.

[Mr.Hyde]

Originally Posted by Mr.Hyde

Hey guys a have a few questions about the 12 circuit ezwiring harness and was wondering if someone can help me out? The truck is a 1968 c10 283 three on the tree no ac lwb.

If I didn't provide enough information I apologize this dark green wire doesn't come off of my fuse block I purchased a 12 circuit ezwiring harness. And am installing that. I followed ezwiring a direction for the alternator already and all I have left is the reverse lights, the ignition switch and the dome light.

I don't have door switches for my headlight so I assume bypass that and run it straight to the dome light.

Also I don't see any type of harness or plug for the Saginaw 3 speed. Would my reverse switch be the one on the column located inside close to the fire wall?

I appreciate the patience like I said I'm not too good or comfortable with wiring but there's only one way to learn..

[ray_mcavoy]

Originally Posted by 72ChevyMan1

I am a little confused. Reason being is I have found different diagrams that do not have the same Colors as my plug. I do not have a tach so I only have 6 holes on my cluster. Does that make a difference? If not do I still use the quoted reference to wires?

You might have been looking at a diagram for a truck with the "3-hole" warning light style cluster. Those have a different pin-out on the cluster connector.

The factory tach (when present) goes in the otherwise unused hole between the speedometer and fuel gauge. It is wired up with it's own separate harness so it doesn't connect into (or result in any changes to) the cluster connector pin-out that I posted earlier.

Originally Posted by Mr.Hyde

Also I don't see any type of harness or plug for the Saginaw 3 speed. Would my reverse switch be the one on the column located inside close to the fire wall?

Yes, a Saginaw 3-speed with the factory column shifter should have the reverse light switch located on the column. I attached a pic of the reverse light switch in my 72 (which also has a Saginaw 3-speed) back in post #11 of this thread.

As a somewhat related side note, there is an electrical switch on some Saginaw 3-speeds ... it's located on the side cover right near the 2nd/3rd shaft and is used for the TCS (Transmission Controlled Spark) emissions system (which is commonly disconnected).

[Mr.Hyde]

Ok ha that switch it not exist any on my trans. So since I have no reverse light wire how will I go about running this?

The ez wiring has a white exciter wire that runs from the harness to the front section which runs to post 2 and 4 on the voltage regulator then 1 and 2 are run to the alternator plug. Alternator has a red which I assume is power and a ground terminal.

[Mr.Hyde]

Ok I'm working on the ignition and reverse lights now. At some point I will have to wire in my tach but that's not a huge concern ATM. I'm wonder where I run power from to the dome port on the headlight switch and where I would run power from to the reverse lights. This is essentially the end of my wiring. The rear end will happen once then bed goes on but its all routed to the back already. Should I run power from the battery with an inline fuse for these connections?

[ray_mcavoy]

Originally Posted by Mr.Hyde

Ok ha that switch it not exist any on my trans. So since I have no reverse light wire how will I go about running this?

Reproduction switches are available if your original is missing from the column. Or you could get creative and mount your own switch somewhere near the linkage in such a manner that it gets activated (contacts closed) when the trans is shifted into reverse.

The factory wiring had a 10A fuse in the fuesbox for the circuit that supplied power to the reverse lights. If the EZ wire harness has a similar fused power feed circuit for the reverse lights, just run that wire to one terminal on the reverse light switch. And then run another wire from the other terminal on the switch back to the lights.

Originally Posted by Mr.Hyde

The ez wiring has a white exciter wire that runs from the harness to the front section which runs to post 2 and 4 on the voltage regulator then 1 and 2 are run to the alternator plug. Alternator has a red which I assume is power and a ground terminal.

You might want to double check those connections. The exciter wire should only go to the #4 terminal on the regulator (not #2 and #4). The regulator's #3 terminal is a voltage sensing wire (typically red) that goes to the main power distribution point. And the regulator's #2 and F terminals are the two that are wired directly to the alternator R & F terminals respectively.

The alternator's power output stud (often marked BAT on the case) uses a heavy gauge (usually red) wire to feed power to the main distribution point. The ground stud on the alternator isn't used in all applications since the alternator is case ground via it's mounting brackets to the engine.

Originally Posted by Mr.Hyde

Ok I'm working on the ignition and reverse lights now. At some point I will have to wire in my tach but that's not a huge concern ATM. I'm wonder where I run power from to the dome port on the headlight switch

The dome terminal on the headlight switch (factory white wire) is a switched ground. When the knob is rotated all the way CCW, it grounds that terminal to complete the circuit for the dome light. Door jamb switches (if used) are also hooked to this same wire so they can also complete the circuit to ground and turn on the dome light.

Power for the dome light (factory orange wire) originally came from the TAIL/STOP/PARK/DOME fuse in the fusebox. This is the circuit that also feeds power to the portion of the headlight switch that controls the tail & park lights. So you can tap into this same power feed to supply power to the dome light.

Originally Posted by Mr.Hyde

... and where I would run power from to the reverse lights. This is essentially the end of my wiring. The rear end will happen once then bed goes on but its all routed to the back already. Should I run power from the battery with an inline fuse for these connections?

If the EZ harness doesn't already have a power feed circuit for the reverse lights, you could create your own with an inline fuse.

[Mr.Hyde]

Sorry yes I do infact have the column switch it's the running power to said switch. There doesn't appear to be any circuit labeled or designated for reverse lights.

So the dome light I just branch out via the stop switch circuit prior to the actual brake switch? Then from that triple split I would run it to the headlight switch and back to the dome light since I don't have door jamb switches?

Also my ignition switch is looking merky it states that

Harness side
Ign sw coil-pink goes to ign
Ign sw ign-brown goes to ign
Ign sw power- red with a black splice goes to bat
Ign sw start- purple goes to start
Ign sw acc- orange goes to acc

Switch side is...
Bat-red
Sol-purple
Acc-brown
Ign-pink

So that means I have pink and brown running from harness too brown ign terminal in switch. Would these get spliced in together?

Btw my only regret is not getting the larger harness

[ray_mcavoy]

Originally Posted by Mr.Hyde

Sorry yes I do infact have the column switch it's the running power to said switch. There doesn't appear to be any circuit labeled or designated for reverse lights.

Yeah, if you don't have a power feed for the reverse lights, you'll have to run your own with an inline fuse.

Originally Posted by Mr.Hyde

So the dome light I just branch out via the stop switch circuit prior to the actual brake switch? Then from that triple split I would run it to the headlight switch and back to the dome light since I don't have door jamb switches?

Yes, the power feed wire (factory color was orange) will have a triple split so it feeds power to the stop light switch, headlight switch, and dome light.

The white wire will run from the dome light to the switched ground terminal on the headlight switch.

Originally Posted by Mr.Hyde

Also my ignition switch is looking merky it states that

Harness side
Ign sw coil-pink goes to ign
Ign sw ign-brown goes to ign
Ign sw power- red with a black splice goes to bat
Ign sw start- purple goes to start
Ign sw acc- orange goes to acc

Switch side is...
Bat-red
Sol-purple
Acc-brown
Ign-pink

So that means I have pink and brown running from harness too brown ign terminal in switch. Would these get spliced in together?

Yes, it sounds as though you need to hook both the pink (coil) and brown (ign) wires from the harness to the IGN (factory pink wire) terminal on the ignition switch.

[Mr.Hyde]

I will give this a try not sure I can post pictures from my phone of the diagram but will when I get home if not.

[_Ogre]

So the dome light I just branch out via the stop switch circuit prior to the actual brake switch? Then from that triple split I would run it to the headlight switch and back to the dome light since I don't have door jamb switches?

to be clear your dome light has 2 wires that hook to the headlight switch
the orange wire on the pic gets power from the brake light circuit which also feeds your dome light
your dome light has 2 wires: 12v+ and a ground wire: the 12v+ comes directly from the orange wire

to turn on the dome light you need to ground the dome light, either thru the headlight switch or the door switches
the pic from post #5 shows the white dome/courtesy ground
this is where you hook the ground wire for the dome light to turn it on

the reason the dome light uses a grounded switch is that any ground can turn it on
whether that ground is the headlight circuit or door pins it does not matter
while your pickup only has one switch, the 4 door cars of that era had the headlight switch and 4 door pins
any door pin also goes to ground



your brake circuit is currently feeding the side marker lights, dome light, the reverse lights and (obviously) your brake lights
this is the same as the original brake circuit