• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Guage and ground question

Rdtrip

New Member
Joined
Apr 13, 2023
Messages
43
Loc.
Fenton Michigan
I have this 66 bronco I'm restoring. Brand new wiring harness for dash, headlights, tail lights, etc from Bronco Graveyard. I have everything connected as per the schematic,and it mimicked the factory set up I disassembled. I have a few ground wires that do not show where they connect, as well as courtesy light wires(which may be the separate ones I haven't installed yet.) So my question is where do I attach the extra ground wires from the harness, and is it going to work with the old cluster? The cluster was cleaned and re-used, and the grounding points around the mounting screws and all grounds have bare metal and all paint was removed to make sure if a good connection. I have no pigtail from the column and the wires are different colors from original in comparison to the new harness. All help will be appreciated!
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,619
Regarding the different wire colors, I don’t suppose you kept the old ones by any chance. Did you?
This is something we need to document because some colors in 66 were different than the rest of the years, and quite often the modern reproduction parts are simply wrong.
So very curious as to what the actual differences are.

Regarding the grounds, are these strictly for the dash harness? If so, any extra pigtails with ring terminal sticking out, probably just mount to the dash.
I know there was at least one ground wire in my 71 harness that was attached to the lower portion of the dash.
In other words, look for a convenient hole within reach of the wire in question.
If nothing around, make your own.

This also highlights the need for making sure that the dash itself is grounded. And by extension, all the body parts are bonded/grounded to each other.
The original battery ground was to the engine, of course, but also to the passenger side wheel well.
This was the only body ground supplied by the battery from the factory.
At the time, when these were new, it was expected that all the welded body panels would play nice and talk to each other and let electrons pass. But in the almost 60 years since, that has degraded quite a bit.
If you want a restoration, but want it to work well, you should hide some ground straps. Out of sight, but connecting body panels to each other. Especially the firewall/tub.
From there, just make sure that the dash connections are very secure and clean to the body. Just like you did with the cluster to the dash panel itself.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,619
Hmm, I wonder if one of the ground wires attaches somewhere on the steering column brace/support?
 
OP
OP
R

Rdtrip

New Member
Joined
Apr 13, 2023
Messages
43
Loc.
Fenton Michigan
Regarding the different wire colors, I don’t suppose you kept the old ones by any chance. Did you?
This is something we need to document because some colors in 66 were different than the rest of the years, and quite often the modern reproduction parts are simply wrong.
So very curious as to what the actual differences are.

Regarding the grounds, are these strictly for the dash harness? If so, any extra pigtails with ring terminal sticking out, probably just mount to the dash.
I know there was at least one ground wire in my 71 harness that was attached to the lower portion of the dash.
In other words, look for a convenient hole within reach of the wire in question.
If nothing around, make your own.

This also highlights the need for making sure that the dash itself is grounded. And by extension, all the body parts are bonded/grounded to each other.
The original battery ground was to the engine, of course, but also to the passenger side wheel well.
This was the only body ground supplied by the battery from the factory.
At the time, when these were new, it was expected that all the welded body panels would play nice and talk to each other and let electrons pass. But in the almost 60 years since, that has degraded quite a bit.
If you want a restoration, but want it to work well, you should hide some ground straps. Out of sight, but connecting body panels to each other. Especially the firewall/tub.
From there, just make sure that the dash connections are very secure and clean to the body. Just like you did with the cluster to the dash panel itself.
Thank you for the reply DirtDonk. I do have a boogered old headlight harness that was removed, and half of it is cut up and missing connectors. I do NOT have a dash harness unfortunately. I have no idea where it went, but I did have 2 of them from donor 66's and someone around here tossed all of it. I can tell you this, it is a brand new body from Bronco Graveyard, built in my shop. I have grounds from the battery to the core support, to the engine block, and engine block to frame. All bare metal connection points. I've followed the diagram provided with harnesses from Bronco Graveyard, and I'm just not sure why I have extra grounding connectors in the harness. I pull the headlight switch halfway,I get really bright parking lights,pull all the way and nothing on those front lights. I also only have power from the new harness for the left side tail light, no power to the connection for the right side tail light. Weird. I also have a flasher light for the dash that starts out a solid light, and within seconds it flashes fast. Not what I typically see with an emergency flasher. So I have some things to figure out yet.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,619
You can’t post pictures directly to the discussion until you pay the 12 bucks a year to become a contributor.
There are other ways that don’t cost money however, if you go to another online hosting site and post your link here. Otherwise, the easier and still free method would be to post some pictures in your “garage“ and “gallery“ functions in your user CP above.
At some point though, many of us (most of us?) have found that the 12 bucks is a small price to pay to keep the site happy and healthy (and Jon/admin too!) and easily upload pictures.
Up to you though.

Regarding the grounds, are they pure black or do they have a stripe? Are they marked like modern aftermarket harnesses, or are they pure reproductions with no other markings?

The front light issue you’re dealing with is most likely piss poor parts from the overseas suppliers, add an old headlight switch.
Being a 66, if it’s an original switch, or an original replacement from the old days, your front running lights only come on in the first click position.
As soon as you turn it to the second click, the headlights come on and the front running lights turn off.
That was normal back then, and changed in 67 or 68. After that all running/parking lights stayed on even when the headlights were on.

The bright position is because (again, probably) most reproduction turn signal buckets are wired backwards! Been this way for at least 10 years and they just don’t seem willing to fix it.
That’s why every time we get a shipment in, we take them all out of the boxes and someone sits there and reverses the contacts in the socket.
Makes for a fun few hours of work every time we get an order of them.

So those are at least a couple of things to check out regarding your front lamps. Not sure about the other stuff yet.
 

Brush Hog

Full Member
Joined
Mar 16, 2022
Messages
240
Loc.
NorCal
I had all sorts of light and gauge issues after installing a painless harness. A good, new ground to bare metal from dash to body (think I went to firewall just below windshield frame) solved 99% of my problems. The other problems were just LED polarity.
 
OP
OP
R

Rdtrip

New Member
Joined
Apr 13, 2023
Messages
43
Loc.
Fenton Michigan
Awesome, I'll look into paying the $12. I appreciate the site, the admin and all the good info too!
As far as the headlight switch, it's a repop as well as the ignition switch. The only old switch I'm using is for the emergency flasher. I was told of the headlight on, parking lights go off thing in a few reads too. I am at the point in reassembly now, that I need the dash wired up as correctly as I can get it.
Ground wires I was speaking of are a pair tied together at the end,one black, one black and green. The others by themselves are black and green stripe. One has a male spade, the rest are female 90° ends. All is connected everywhere to every switch and location it should be, and there were no markings other than color for me to decipher it. The schematic doesn't show them connected to anything.
I will look into those aftermarket front lights too and compare it to the old ones I have that work and see if there's a difference. Thanks again, I appreciate your assistance!
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,619
It’s very likely the newer, even though modern make, switches retain the same function as the old, depending upon which pin location the wires are located in.
Even my 64 , 65 and 66 Chevies had the old style where the running lights went out when you turned the headlights on. But moving one wire to a different location in the connector changed it to where the lights stayed on.

Be careful with black wires with a green stripe!
At least for later model years, black with the green was accessory power wire.
The two together, if they are near the cluster, are probably one for the back of the ignition switch (the long stud) and the other to ground the cluster.
But that’s only a guess on my part, so don’t do anything about it without confirmation.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,619
Ground wires I was speaking of are a pair tied together at the end,one black, one black and green. The others by themselves are black and green stripe.
I don’t know exactly when the rest of the automotive industry, or the world at large adopted Black as a standard ground color, but FORD was late to the party in this regard and used Black for a lot of things that were not grounds.
Back-up lamps, brake lamps, accessory wires, for example.
One has a male spade.
It’s male? Is this black with green also?
Reason I ask is that there should be a female spade connector that goes to the instrument cluster voltage regulator. Do you have that one already handled?
the rest are female 90° ends.
To my knowledge, FORD never used 90° push-on connectors for any type of ground anywhere. Too insecure and too prone to loosening up.
There could be one harness section with three of those, that is for power to the gauges, from the IVR.
All is connected everywhere to every switch and location it should be, and there were no markings other than color for me to decipher it. The schematic doesn't show them connected to anything.
Definitely looking forward to seeing some pictures!
Are there any details on the JBG site?
I will look into those aftermarket front lights too and compare it to the old ones I have that work and see if there's a difference. Thanks again, I appreciate your assistance!
And you are still using regular bulbs, and not LEDs. Correct?
 
OP
OP
R

Rdtrip

New Member
Joined
Apr 13, 2023
Messages
43
Loc.
Fenton Michigan
It’s very likely the newer, even though modern make, switches retain the same function as the old, depending upon which pin location the wires are located in.
Even my 64 , 65 and 66 Chevies had the old style where the running lights went out when you turned the headlights on. But moving one wire to a different location in the connector changed it to where the lights stayed on.

Be careful with black wires with a green stripe!
At least for later model years, black with the green was accessory power wire.
The two together, if they are near the cluster, are probably one for the back of the ignition switch (the long stud) and the other to ground the cluster.
But that’s only a guess on my part, so don’t do anything about it without confirmation.
I am 99.999 sure they're all grounds, they are identical to the ones specifically for the cluster. I've tested them all and I literally have 1 red/white male single wire, with power with the key on, nothing with key off. Black & black/green have no power at any point. I wish I knew if they were for options or something. I hate wires left open without knowing what they're for..but those are the only wires not accounted for. I'll be chasing all this again in the morning. Thank you
I don’t know exactly when the rest of the automotive industry, or the world at large adopted Black as a standard ground color, but FORD was late to the party in this regard and used Black for a lot of things that were not grounds.
Back-up lamps, brake lamps, accessory wires, for example.

It’s male? Is this black with green also?
Reason I ask is that there should be a female spade connector that goes to the instrument cluster voltage regulator. Do you have that one already handled?

To my knowledge, FORD never used 90° push-on connectors for any type of ground anywhere. Too insecure and too prone to loosening up.
There could be one harness section with three of those, that is for power to the gauges, from the IVR.

Definitely looking forward to seeing some pictures!
Are there any details on the JBG site?

And you are still using regular bulbs, and not LEDs. Correct?
I have the ivr handled, it is also appears I wired it correctly but not yet tested for voltage, per se, other than checking for lights and any needle movements. None of the harness is original, every wire is new. It's all aftermarket stuff from Jeff's Bronco Graveyard. They're like 10 minutes from me and have supplied the majority of what I've needed to complete this thing. Yes, standard bulbs, NO LED anything.
 
OP
OP
R

Rdtrip

New Member
Joined
Apr 13, 2023
Messages
43
Loc.
Fenton Michigan
So I have another issue, it seems the electrical is starting to get to me. I do get overwhelmed sometimes, but in this case it's all new wiring and nothing old except the emergency flasher which seems to function fine. I got the new headlights in, every harness is new, as is headlight switch and bright light switch... I reversed the wires on the aftermarket turn signals, so they light up on the dim and blink bright with the emergency flasher so that's fixed. I have high beams, but no low beams. Indicator light for brights works as it should. So where would I try to find a low beam issue? I also still have no power from the dash harness to supply power to the right side tail light, green & orange. Brown & yellow supply left tail and work with lights, but no brake lights yet (also don't have fluid in the system and pedal is tied to the firewall so I don't clip my face on them again. I'm kinda stumped but keep reading and looking for the problem/answer. Any help with this one? Thank you!
 

Oldtimer

Contributor
Jr. Member with Sr. moments
Joined
Feb 4, 2005
Messages
1,795
Loc.
Sunnyvale, CA
Low beam:
You have high beam lights, so headlight switch is supplying power to hi/low dimmer switch (bright light switch).
Dimmer switch has 3 contacts, HI, IN, LO.
If wires are miss connected you could have 12v going to HI contact, and hi beams connected to IN contact. This would give you hi beam, but no low beam.
 
OP
OP
R

Rdtrip

New Member
Joined
Apr 13, 2023
Messages
43
Loc.
Fenton Michigan
Low beam:
You have high beam lights, so headlight switch is supplying power to hi/low dimmer switch (bright light switch).
Dimmer switch has 3 contacts, HI, IN, LO.
If wires are miss connected you could have 12v going to HI contact, and hi beams connected to IN contact. This would give you hi beam, but no low beam.
Thank you. I will look into it Monday and reply with what ends up happening. It's all new stuff, but I have had the aftermarket stuff wired incorrectly already so that may also be the case. The investigation continues...
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
51,619
A new dimmer switch is just as likely to be defective out of the box as anything else these days. Or, as you said, it could be wired wrong as well.
Easy to test a couple of different ways as well.
Pull the connector off the switch, and check which wire has 12v when the light switch is turned all the way on. Should be the center cavity/wire, if I remember. Maybe others can confirm that.
Take a short piece of wire to use as a jumper, and connect that live wire to each of the other two wires. Touching it to one of them will illuminate the high-beams (which we already know work) and touching it to the other will (or should) illuminate the low beams.
If the low beams still don't work with a direct jumper, then either the wire from the dimmer switch to the lights is bad, or the lights are bad. Or, if you have a relay harness, perhaps one of the relays is bad, or one of the wires.

Speaking of which... Did you install a headlight relay harness, or are you running the headlights directly off of the headlight switch via the new vehicle harness?

Paul
 
Top