Tach/Gas Gauge Problem

[1badlsc]

Recently i've noticed my gas gauge stays at full & my tach stops when I
turn on my lights. I show a tech article on a common ground problem
that causes this. It said to locate the solid orange #15 wire at the back of
the tach. it also said you can locate this wire behind the drivers side kick panel in the smaller wire harness. I chose the kick panel location ,so as not to pull the cluster out. i actually see 3 solid orange wires.I tapped into one
of them & re grounded(which the article led me to believe i would only
find one orange wire)after tapping into one of the wires the tach worked
with the lights on put jumps around a bit. I don't see any change in the gas gauge. Can anyone help with this.

 

[Drew4002]

I had the same problem, as did many other people on this site. I never heard of the kick panel wiring harness to be an option but it might be. I pulled my cluster out(including the dash) to fix the problem. There is only 1 orange wire back there so its not very confusing. I just regrounded it to a metal screw in under the dash and everything worked fine after. Its not too hard to pull the dash out(that is what most people try to avoid). Its just takes a little time and the removal of a lot of screws! If u do it ur way, u probably will have to reground all 3 orange wires. After I fixed mine, the tach did jump around for a couple days when i revved it up because of the magnetic force it creates, but went away a couple days later. It should go away soon after. Hope this helps!

 

[1badlsc]

Gas Gauge

Does regrounding the tach wire have any effect on the gas gauge.

 

[Drew4002]

Yes. Regrounding the wire behind the cluster will fix the tach and the gas guage. Until then, ur gonna have to use ur trip or odometer to tell u how much gas u have. I average about 300 miles per tank.

 

[skymasteres]

This is a really easy repair to do. First of all I have heard of the hunt for the wire technique. I do not reccommend it. Here is why:

In my opinion you are much better off removing the 3? scerws (I can't remember) that hold the trim over the intamint cluster and the 3 screws that hold the cluster.

Once you have it unscrewed, just pull it straight out, unplug the harness, and reground the wire. The reasemble. Enjoy a working gas gauge and tachometer.

 

[1badlsc]

Gas/tach Problem

Thanks guy's .I'll take care of this over the weekend & get back to you Monday

 

[1badlsc]

Regrounding Tach Wire

I regrounded the tach wire behind the cluster. I not sure if i have a new
problem,but my car is not getting spark. It cranks & at times seems like it's going to catch. I bought a new distributor & installed it . It started up & ran
for a minute .Then went back to the same problem ,cranking ,but no spark
I never had this problem before.

 

[OldSchool1]

I regrounded the tach wire behind the cluster. I not sure if i have a new
problem,but my car is not getting spark. It cranks & at times seems like it's going to catch. I bought a new distributor & installed it . It started up & ran
for a minute .Then went back to the same problem ,cranking ,but no spark
I never had this problem before.

Congratulation and condolences.

They shouldn't be related.

Did you verify that you're not getting spark to the spark plug wires by hooking up a timing light or test light? If your test equipment is flashing then you need to verify fuel. How much fuel pressure do you have under the hood?

 

[DebSol]

Just completed this repair on mine. Easy fix, and one I would have spent a ton of time finding. Thanks to the forum, and to all who've figured this one out.

 

[Lscr1]

Sorry to revive an old thread but I just pulled the cluster and dash off my 87 Mark VII to fix a number of common problems. The Headlight/Panel Dim switch and a number of defunct dash lights. I too have the "Orange Wire" problem with a non existent fuel gauge and jumpy RPM and Speedometer with the lights on.

Questions: - I'm going to tap into the Orange wire and would like to ground it somewhere close. Any recommendations? I was always told that when grounding a wire on a car it should be onto the body.

Per my picture below for a 1987 this looks like a newer dash cluster(1990+). I've seen varying stories as to what to ground. Should I take the Orange and Black wire and reground to the emergency brake area. Plus, check the ground strap thing at the tank?

This is just a ground right? I can just take the existing Orange wire, cap, tap and tuck it?

Thanks!

 

[OldSchool1]

Hi,
Your pictures are NOT coming through, but I can offer some advice.

If you have an ORIGINAL ignition switch in your 1987, then that is the FIRST thing to replace. Trying to troubleshoot ANY accessory issues with an original ignition switch in the car will only frustrate you and empty your pockets.

If you own LSCR, then almost ANYTHING can be going on with your gauges as I don't remember all of the modifications done to the car.

A ground is a ground is a ground. Find a small hole in the body near where you want to add a ground. If none are found, then make your own with a 1/8 inch drill bit. Find a 10x3/4 inch, self tapping screw and washer the same size or larger than the hole. Secure the new ground wire to the screw. Secure the screw to the body. Done deal.

Come back here and let us know what you find FIRST in your steering column, and then how you plan to proceed.

Post Script
We've found that the orange wire ground fix only pertains to 1990-1991 Mark VIIs. See the EVTMs of those years for a better understanding. You may begin the debate now ... but I would start a new thread if I were you

 

[Lscr1]

Hi,
Your pictures are NOT coming through, but I can offer some advice.

If you have an ORIGINAL ignition switch in your 1987, then that is the FIRST thing to replace. Trying to troubleshoot ANY accessory issues with an original ignition switch in the car will only frustrate you and empty your pockets.

If you own LSCR, then almost ANYTHING can be going on with your gauges as I don't remember all of the modifications done to the car.

A ground is a ground is a ground. Find a small hole in the body near where you want to add a ground. If none are found, then make your own with a 1/8 inch drill bit. Find a 10x3/4 inch, self tapping screw and washer the same size or larger than the hole. Secure the new ground wire to the screw. Secure the screw to the body. Done deal.

Come back here and let us know what you find FIRST in your steering column, and then how you plan to proceed.

Post Script
We've found that the orange wire ground fix only pertains to 1990-1991 Mark VIIs. See the EVTMs of those years for a better understanding. You may begin the debate now ... but I would start a new thread if I were you

OldSchool! Thanks for the info. Turns out, I have a 90+ Speedometer(120MPH). You know, I noticed that my AC climate control was buggy. I randomly rotated the key forward a bit and it corrected the problem. That and installing a new battery I'll try grounding the Orange and Black Wire first to see what happens. I also bought a replacement Panel Dim/ Headlight switch. Unbelievable how much corrosion in the form of filings are sitting at the bottom of that trim piece directly underneath of it. It also was extremely difficult to rotate. Thanks for screw sizes, etc.!!!

My dash lights should be in today or tomorrow I'll let you know what comes of it.

 

[OldSchool1]

You're welcome.

Click the IGNITION SWITCH link in my signature and replace this first first first.

 

[Lscr1]

You're welcome.

Click the IGNITION SWITCH link in my signature and replace this first first first.

To be honest, I'm a bit frustrated and baffled at this point.

1. The absolute first thing I did was replace the panel dim/Headlight switch. Boy was it a mess. There were shavings everywhere and it was completely corroded.

This is where it gets interesting:

I went ahead and bought LED Bulbs to see what it would look like but also spruce it up a bit. All of them worked except for the top and bottom right side bulbs. I switched sockets and bulbs. I went ahead and repeated the same process with all standard bulbs. Same result. Oddly enough, with LED's those two bulbs/sockets became active when I turned the headlights off This only happened with the LED's not the standard bulbs. The only thing I can possibly guess is that with LED's and with the headlights off the only reason they would turn on is if there was some sort of risidual current lighting them up

My right side turn signal was not turning on with either type of bulb nor did exchanging sockets help. On an offnote, the turn signals are pretty slow to flash. I haven't driven the car in a while but once I engage one side it sticks for about 2-3 seconds and than slowly starts flashing. Standard bulbs, LED's and switching sockets didn't help the right side. The highbeam indicator and left side worked just fine.

My Climate control bugged out for a bit (flashing the temp). After restarting the car it seemed like it corrected itself.

I didn't do the Orange Wire fix as of yet. And...since this is an 1987 Harness attached to a 1990+ Instrument cluster from what I could tell their looked to be two Orange wires on the harness.

And if that wasn't enough when I open up the driver side door, the interior lights do not automatically kick on. At one point I was able to get them to turn on with the door opened up (not with the panel dim switch manually turning the lights on). Really strange.

Any help would be greatly appreciated.

 

[OldSchool1]

... Any help would be greatly appreciated.

Sure.

If you have an ORIGINAL ignition switch in your 1987, then that is the FIRST thing to replace. Trying to troubleshoot ANY accessory issues with an original ignition switch in the car will only frustrate you and empty your pockets.

If you own LSCR, then almost ANYTHING can be going on with your gauges as I don't remember all of the modifications done to the car.

A ground is a ground is a ground. Find a small hole in the body near where you want to add a ground. If none are found, then make your own with a 1/8 inch drill bit. Find a 10x3/4 inch, self tapping screw and washer the same size or larger than the hole. Secure the new ground wire to the screw. Secure the screw to the body. Done deal.

Come back here and let us know what you find FIRST in your steering column, and then how you plan to proceed.

Post Script
We've found that the orange wire ground fix only pertains to 1990-1991 Mark VIIs. See the EVTMs of those years for a better understanding.

 

[Lscr1]

Sure.

If you have an ORIGINAL ignition switch in your 1987, then that is the FIRST thing to replace. Trying to troubleshoot ANY accessory issues with an original ignition switch in the car will only frustrate you and empty your pockets.

If you own LSCR, then almost ANYTHING can be going on with your gauges as I don't remember all of the modifications done to the car.

A ground is a ground is a ground. Find a small hole in the body near where you want to add a ground. If none are found, then make your own with a 1/8 inch drill bit. Find a 10x3/4 inch, self tapping screw and washer the same size or larger than the hole. Secure the new ground wire to the screw. Secure the screw to the body. Done deal.

Come back here and let us know what you find FIRST in your steering column, and then how you plan to proceed.

Post Script
We've found that the orange wire ground fix only pertains to 1990-1991 Mark VIIs. See the EVTMs of those years for a better understanding.

Jeez you're quick

Would this work? :

http://www.fordpartsgiant.com/parts/ford-switch-assy-ignition_f29z-11572-d.html

Thanks for the tech article. Looks like it should be a snap to replace.

You mentioned:

"A ground is a ground is a ground. Find a small hole in the body near where you want to add a ground. If none are found, then make your own with a 1/8 inch drill bit. Find a 10x3/4 inch, self tapping screw and washer the same size or larger than the hole. Secure the new ground wire to the screw. Secure the screw to the body. Done deal."

If the Orange wire only applies to pre 90's - What exactly am I regrounding?

Thanks again. If that's the bugger than I'm next day airing it. Of course it started pouring and my sunroof started leaking while I was doing all of this. That and had a towel over my head to see the lights (sun setting). My fiance thought I looked pretty ridiculous

 

[OldSchool1]

Jeez you're quick

No. I just work with smoke and mirrors.

Would this work? :

http://www.fordpartsgiant.com/parts/ford-switch-assy-ignition_f29z-11572-d.html

Yup and depending on where you live, you can walk into any AdvancedPepZone and ask for a 1984 to 1989 ignition switch and walk out with said part in hand in under ten minutes for under $20.00

Thanks for the tech article. Looks like it should be a snap to replace.

You are welcome.

You mentioned:

"A ground is a ground is a ground. Find a small hole in the body near where you want to add a ground. If none are found, then make your own with a 1/8 inch drill bit. Find a 10x3/4 inch, self tapping screw and washer the same size or larger than the hole. Secure the new ground wire to the screw. Secure the screw to the body. Done deal."

If the Orange wire only applies to pre 90's - What exactly am I regrounding?

1) The "Orange Ground Wire Fix" is a HIGHLY debated issue on the net and is not the end all to cure all. IT IS MY EXPERIENCE, after consulting many owners and mechanics and EVTMs, that it will only actually cure a faulty ground to our STOCK instrument clusters in STOCK 1990 and 1991 Lincoln Mark VIIs. Again, HIGHLY debated and often ended when an EVTM is laid out on the table showing exactly WHICH cars have it and WHAT accessories they serve and WHERE the original instrument cluster gets it's ground.
2) After replacing your ignition switch (is there an echo in here?), if the problem still exists, then what you are grounding is about four circuits (courtesy lighting, interior lighting, exterior lighting, latte machine) that all work ~through~ your lamp switches. Since most of our accessories are normally hot at all times, Ford breaks the ground in most cases to open the circuit. However, some of the circuits need to be broken through relays as they need to be powered under different circumstances sooo ... (deep breath) one path may work properly but another path may have a bad ground so that you'll only notice a problem when the headlights are MANUALLY turned on but never when they are AUTOMATICALLY turned on or vice versa. One condition has a GOOD ground and the other condition has a BAD ground but it's still the same circuit (IE, speedometer illumination has three possible paths for it's circuit). (Another deep breath) To answer your question, you won't know what to ground until you know what circuit is faulty. You won't know what circuit is faulty until everything from the battery to the anomaly has been tested and is in good working order. You won't know that until the ignition switch has been replaced (damn echo is back).

Thanks again. If that's the bugger than I'm next day airing it. Of course it started pouring and my sunroof started leaking while I was doing all of this. That and had a towel over my head to see the lights (sun setting). My fiance thought I looked pretty ridiculous

You are welcome.

I agree with her.

Test, repair/replace, test ... or empty your pockets and chase your tail around the driveway.

I need a nap.

 

[Lscr1]

I went ahead and replaced the Ignition Switch. I now know what a Tamper Proof Torque Screw looks like If you have the switch aiming straight at you it looks as though the top two middle prongs had signs of heat/fire. The harness looks like it was wire tape from what I can guess on the Grey and two Yellow wires. Not sure. The black housing had signs of heat warpage.

All of my original problems still remain. Two bulbs on the dash cluster still do not kick on. The turn signal on the right still will not light up and the interior lights will only turn with the passenger side door open, not the driver side. The lights do turn on manually. Also, there was a random wire hanging unattached to anything.

http://www.4shared.com/photo/FZ8RhW_N/2012-08-23_185647.html?refurl=d1url

What to do now?

Update: After exiting the car, waiting a few minutes and opening up the driver side door, all of the interior lights do turn on. After about a minute, they all turn off. With the car running and the driver side door open, the lights do not automatically turn. Manually they work just fine.

I reinstalled the LED bulbs into the instrument cluster and was dumbstruck by what I found. Those two sockets now work. But.....when the key is turned forward or with the car running those two in the right side corner turn off and the rest are on. When the headlights are off (I did this at night) and I turn the key forward those two bulbs and only those two bulbs turn on. Really strange. With the headlights off (plus all of the auto dim switches etc. are off) the cluster should be dead. Something seems way off here as though they're somehow tied into the other interior lights.

Tidbits: There is an aftermarket Alpine Alarm system installed. I lost the remote long ago and do not use it.

I'm at a real loss as to what the issue could be. The grey and the yellow wires having tape wrapped around them in the steering column, aftermarket alarm system, 1990+ Cluster in a 1987 Mark. I don't know where to start.

 

[OldSchool1]

I went ahead and replaced the Ignition Switch.

Good.

I now know what a Tamper Proof Torque Screw looks like

Good.

If you have the switch aiming straight at you it looks as though the top two middle prongs had signs of heat/fire.

Not good ... but good that you replaced it.

The harness looks like it was wire tape from what I can guess on the Grey and two Yellow wires. Not sure.

This is called a modification.

The black housing had signs of heat warpage.
...

Not good ... but good that you replaced it.

The rest of your post discusses modifications.

Unless the person that made the modifications can tell you what they did and how to reverse it, you'll spend TENS of hours doing continuity tests to see what circuits go where and when and why, just to get your non 1987 instrument cluster to properly light in your 1987.

I'm glad that you got the opprotunity to see that something as simple as 1/2 of a speedometer lighting system can have two or more sources for switching ground from open to close.

I cannot help with modified systems.

 

[Lscr1]

Thanks for the heads up and advice. I think I'm going to try the Orange wire fix. It really couldn't hurt at this point. I found the tech article online. Minus the #15 Orange wire should I also ground the Black wire?

 

[OldSchool1]

I dunno.
I cannot help with modified systems.

 

[Lscr1]

Is there a manual method for closing the sunroof? I drained the battery over the weekend after cleaning out the car (left the doors open). Car would not accept a jumpstart or chargebox. Melted two sets of Jumper Cables and fried the battery. Seems like there is a serious dead short somewhere in the system.

 

[OldSchool1]

If it is a stock moon roof with no frame around the roof opening, then open the moon roof cover above the rear seat armrest. You'll find a hex socket that can be turned with the above key or similar.