HELP 76 dart gas an temp gauges wont work!!!

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snowcrow

snowcrow

2 Time dart owner
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I know this should be a easy fix for some but I'm new to wiring for gauges. I was told by two mechanics that the reason my 76 darts gauges dont work is cause they are bad or broken gauges. Ive noticed the car has wires clipped here an there throughout, some that I can see hanging under the dash. The three that I can see easily are two yellow wires coming out from the harness tape and one red wire that is a few inches poking out and cut off behind the yellow two. The car runs and drives just fine minus the two gauges.
 
dont forget to include your make/model and year. some of these cars have a voltage limiter behind the cluster
 
You really need to get yourself a factory shop manual. You can order reprints or CDs various places including Ebay.

Generally, there are several areas that stop gauges from working

The basic circuit is power from ignition switch feeds to instrument cluster, goes to the instrument voltage limiter, and that feeds reduced voltage to the fuel and temp gauge, then the sender terminal of each gauge feeds off to the senders

The connector on the cluster could have loose pins or corrosion, preventing proper voltage from reaching the cluster

The PC board on the cluster could be corroded and not properly grounded

The "socket" which the limiter device plugs into may not be making good contact

The limiter itself could be bad

The gauges could be bad

The sender wires could be broken

The senders could be unhooked or defective.

Because BOTH gauges are not working, I would immediately pull the cluster

Unhook the battery ground

This is easier if you drop the steering column. Just remove the trip below the column, remove the bolts at the floor plate, and the two or three nuts/ bolts that hold the column up. You should be able to drop the column in the seat

Reach up with your hand and find and unclip the speedometer cable. Remove appropriate trim screws and remove the cluster. Be careful with the harness.

Find a ground point on the PC board and hook a wire from there to the body.

The voltage limiter looks something like this:

http://www.rtspecialties.net/prodimages/2258413.jpg

You should be able to LOOK at the cluster and pc board and trace the copper conductors. Each gauge has a trace leading to the voltage limiter. The OTHER terminal of each guage leads directly to the harness connector. These terminals go to the sender.

Ground each sender terminal with a clip lead, and hook up power, turn the key to "run". The gauges should head dramatically towards full

IF not, check with a meter or light on the IVR side of the gauges to see if you have pulsating voltage. If so, try tightening the guage nuts. If no pulsing voltage, check for power coming IN to the limiter, which should be "same as battery. IF this is good, replace the voltage limiter.

IF the limiter is showing a pulsing voltage at the gauge terminals, and you have the senders grounded, you may indeed have bad gauges. Try hooking a 9V battery BRIEFLY to each gauge to see if it moves. Don't leave that hooked up any longer 'n you need to in order to check.
 
Not really. If you are going to get serious about owning one of these cars, you need a shop manual

Much of the mechanical stuff is the same as the 72 manual, which you can download for free right here:

http://www.forabodiesonly.com/mopar/showthread.php?t=132309&highlight=manual,+download

but the wiring diagrams in that won't do you much good. You should be able to buy one on CD for 25-40 bucks.

The thing about one on CD, and I do this with the ones I've downloaded all the time, is that you can take a "screenshot" of part of a diagram, and post it on here

This diagram is one example, a screenshot right out of one of the "electronic" manual files

1zvpy7s.jpg


You can get usable wiring diagrams over at "MyMopar" but they are hardly as comlete as the shop manual:

http://www.mymopar.com/downloads/1976/76DartA.jpg

http://www.mymopar.com/downloads/1976/76DartB.jpg

came from here

http://www.mymopar.com/index.php?pid=31
 
I have a Multi volt and ohm reader thing from craftsman but don't know how to use it, would it help?
 
First tighten the sheet metal nuts on the back of the cluster easy n fixes alot of them.
 
your are going to have to either (A) pull the cluster and go through it (B) take it to a shop and get bent over by a "mechanic" that chances are he really knows as much as you do about it unless you get lucky or (C) live with it.

if i were you, i would learn about it that way you will have knowledge for the future if it fails again and you wont be at a "mechanics" mercy and you wont have an empty wallet every time you see him. make sure you unhook the battery before you go diggin in. you really need the electrical manual and patience. there is an order in which these parts unbolt and come out. i have taken my cluster out a couple of times and it really is basic. just remember not to yank on anything. these clusters have a pin connector on the back of them that are really easy to break.
 
Most likely you do have a bad instrument voltage regulator or a bad connection to it. Weather it's internal or external needs to be determined. In any case you need to pull the instrument cluster to fix it.
 
same issue here actually, i replaced my gas sender and nothing happend. switched out my voltage thing. now I should really look at that again.
 
the artful dodger said:
same issue here actually, i replaced my gas sender and nothing happend. switched out my voltage thing. now I should really look at that again.
Click to expand...

any luck with this? im thinkin about tracing my wire to see if its ok then takin the dash apart. only problem is i drive this car regularly so its hard to do anything TOO time comsuming.
 
Its not impossible to drive the car without an instrument panel.
I'm not going to recommend doing that. I will say I've been there done that.
To take the instrument panel to the workbench and properly service it is the best route.
Reaching in , under, around, while its in the dash can do more harm than good.
 
just found out im missing my voltage or electro-mechanical regulator. this might be the reason im not getting any fire in my wires.
 
snowcrow said:
just found out im missing my voltage or electro-mechanical regulator. this might be the reason im not getting any fire in my wires.
Click to expand...

LOL Well missing parts is always a legit reason not to work!!!
 
snowcrow said:
just found out im missing my voltage or electro-mechanical regulator. this might be the reason im not getting any fire in my wires.
Click to expand...
1976 cars should have an electronic voltage regulator. It is a thin, square box with a special triangular connector with 2 pins. If missing the connector, a junkyard is the best source for both, though I think you can buy new connectors still. A new Vreg is ~$12 at most parts stores.
 
BillGrissom said:
1976 cars should have an electronic voltage regulator. It is a thin, square box with a special triangular connector with 2 pins. If missing the connector, a junkyard is the best source for both, though I think you can buy new connectors still. A new Vreg is ~$12 at most parts stores.
Click to expand...

turns out the in dash regulator around here is 37 at auto zone and 54 at napa. it took them a while to find it cause they kept pulling up the one under the hood.
 
ugh just found out when i went to put the volt regulator in that there is a break in the printed circuit board near the volt regulator. should i solder it or just get a new cluster or printed board.
 
You can repair broken traces easily. Cut out the damaged area with a razor knife. Apply some soldering flux, then with a small low temp iron, place a small drop of solder on the trace. Cut a lead off a resistor to bridge the gap, then solder it on. Resistor leads work perfect because they are already tinned and solder easily.
 

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snowcrow said:
turns out the in dash regulator around here is 37 at auto zone and 54 at napa.
Click to expand...
Sorry, I was thinking of the one under the hood when you said "electro-mechanical". The 5V Vreg on the dash cluster is expensive, if you get a factory mechanical type. Many people install an electronic one, which is less expensive and much better. I got one on ebay for ~$25, also check IVR. Not like the original, it is a small circuit board you velcro to the cluster.

I agree that fixing traces on these boards is easy. These are old, hand-drawn one-sided wiring boards with wide traces, nothing like fixing a computer motherboard. You can get replacement boards for many models, but ~$100 and a lot of work resoldering components. No need for that since most are repairable.
 
Good for you for working on this. I've had to learn by the seat of my pants over the years on all my old Mopars including rewiring the dash of my 74 Satellite when the wires to the ammeter overheated and melted everything together. The common cause of that issue is an entire chapter in vintage Mopar electrical book.

I echo the need to purchase a factory manual with a factory wiring diagram. There's a wealth of information on those pages including what individual plugs and connectors look like to help in your search. It doesn't take long to teach yourself how to read the diagrams plus you can then ask very specific questions while looking at a reference.

I like the CD's because when I have a greasy dirty job, I print out the pages I need and then toss them when they get finger printed up. You can also go to every section you need for the job and print out a nice little packet before you begin. Plus the bindings on the HUGE factory reproduction manuals always come apart in the shop.
 
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