71 dart instrument cluster

-
J

jeppe

Active Member
Joined
Jul 6, 2022
Messages
32
Reaction score
11
Location
finland
So i just bought 71dart. the fuel and temp gauge dosent work. oil pressure light works and some of the cluster instrument lights work like turn signal light. i have alredy taken the cluster out and cleaned circuit board from corrosion and i did verify that the meters work with battery charger straight to terminals. and how can i verify if my temp sensor if working? it is 1pin.
Thanks in advance :)
 
Check the voltage limiter on the back of the instrument cluster... When it fails, it those gauges won't work...
 
jeppe said:
So i just bought 71dart. the fuel and temp gauge dosent work. oil pressure light works and some of the cluster instrument lights work like turn signal light. i have alredy taken the cluster out and cleaned circuit board from corrosion and i did verify that the meters work with battery charger straight to terminals. and how can i verify if my temp sensor if working? it is 1pin.
Thanks in advance :)
Click to expand...


If you don't have a service manual for your car, you can download one free here:

Service Manuals – MyMopar

Electrical is section/chapter 8, wiring diagrams are in the back of that chapter.... Make sure that you are looking at the Dart wiring diagrams and not the other models...
 
Welcome to FABO from Chicago...
welcome.gif
Welcome to FABO.gif
 
jeppe said:
and how can i verify if my temp sensor if working? it is 1pin.
Thanks in advance :)
Click to expand...


The temp sensor one pin is the positive for the circuit, it gets its ground from the housing...
 
here's how the gages and sender work.
Thermal-Electric Gauges (Session 227) from the 1966 Master Technician's Service Conference

And there's the filmstrip that goes with that, along with a pdf version of the booklet at
Browse MTSC by Model Year – 1966 – MyMopar

For the sensor you can place it in boiling water and measure the resistance. Then check it at room temperature.

For testing the gages alone, you can apply a very low voltage, low power battery as a quick check, or supply power at 5 to 6 Volts, with a resistor in the return wire. Different resistors will mimic the sender in different conditions.
When working voltage limiter will pulse 0 to 8 volts when supplied power. It must have a return path for the current or the bimetal will not heatup and open.
 
jeppe said:
some of the cluster instrument lights work like turn signal light.
Click to expand...
Turn signals are seperate circuit from other indicators.
Instrument illumination is powered when the parking lights are turned on (one click back on the light switch). Does not require the key to be on. If the outside marker lamps are on, then the instrument and radio lights should be on. If not, rotate the light switch knob. If they still don't light up, check the 3 amp fuse in the fusebox.

upload_2022-4-7_9-32-59-png-png.png


digitized service manuals Service Manuals – MyMopar
 
Last edited:
thank you all so much for asnwers. i ordered new solid state voltage limiter so lets see if that works.
 
Mattax said:
here's how the gages and sender work.
Thermal-Electric Gauges (Session 227) from the 1966 Master Technician's Service Conference

And there's the filmstrip that goes with that, along with a pdf version of the booklet at
Browse MTSC by Model Year – 1966 – MyMopar

For the sensor you can place it in boiling water and measure the resistance. Then check it at room temperature.

For testing the gages alone, you can apply a very low voltage, low power battery as a quick check, or supply power at 5 to 6 Volts, with a resistor in the return wire. Different resistors will mimic the sender in different conditions.
When working voltage limiter will pulse 0 to 8 volts when supplied power. It must have a return path for the current or the bimetal will not heatup and open.
Click to expand...

for sensor i checked connection from the body of the sensor to battery - and it has connection. and then i checked ohms from sensor body to the 1 pin and it didint show anything. Does that mean sensor is bad?
 
Usually, the sending units either work or they don't. When I first diagnose a non-working gauge, I start with removing the wire from the sender and attach a jumper wire from the wire terminal to a good ground. I then turn the ignition switch to the ON position. If the gauge starts to move, I immediately turn the switch back off. You don't want to let it stay pegged all the way over and overheat. That tells me the gauge at least works and that the sender is bad. How accurate the gauge is, is another matter. If nothing happens, check the voltage limiter and replace as necessary. You can do this test with the temp, fuel, and oil pressure gauges. When it comes to the fuel sender, make sure it's properly grounded when making the test. There's a ground strap that jumpers across the hose section at the sender. Make sure that's making a good connection each end. If you narrow it down to the fuel sender, hopefully your gas tank is near empty, or, at least below the level of the sender hole. Pull the lock ring, remove the sender, and check the float for flooding. It's pretty common to have a cracked float which causes it to flood and sink, giving you an empty reading on the gauge. New floats are easily found. When installing them, put some grease in the groove where it attaches to the sender arm. Then roll the float into place. Those brass floats are very thin and it's easy to put a hole in one of you just try to snap it into place dry.
 
well i installed new solid state limiter. bench tested the whole instrument cluster and everything worked. Then i putted it in car and nothing worked, even not the turn signals wich worked before. no power to anything, when starting it would crank for like .5 seconds. In one point it started smoking somewhere near light switch but couldn find any bad wires. Now i Taked the limiter of and everything "works" like it used to. And i noticed one more problem, when cranking the engine i think theres no spark. when i let go off key it will start.
 
Jeppe,
All I can say is somehting is wired incorrectly.

My suggestion is to begin with the wiring from the power supplies (battery and alternator), then check the main feeds (key switch, fuse box always hot, headlights, horn). Once those are defninately connected correctly, then check the key switch out going wires.

For the complete factory wiriing diagram, get a shop manual. You can download a digitized manual from www.mymopar.com under Service Manuals.

The standard power supply for 1970 and 71 is like this.
upload_2022-7-9_9-32-57.png

Wire A1 is battery feed.
Wire R6 is alternator feed
These connect at welded junction in the harness.
Notice the ammeter indicates power into or out of the battery. Discharge or charging.

The battery and alternator connect feed Three or four wires from the welded junction.
Wire L1 is for the headlights, there is a circuit breaker in the switch.
Wire Q1 goes to a buss in the fuse box. Parking Lights, dome light, and brake light all are on this buss.
Wire J1 goes to the key switch.
In 1971 power for horn, wire H1, is also connected at this main splice.

When the key is in Start position, brown wire J3, Ignition 2, powers the coil; and yellow wire powers the starter relay.
When the key is in Run position, blue wires J2 get power to the coil and the alternator's rotor; and the black accessory wire gets power for the windshield wiper, turn signals, and additional fused circuits.

We will have to look at the specific diagram for your car to learn the wire route to the instrument voltage regulator.
--------------------------------------
looks like its spliced into the J2 (run) circuit.
upload_2022-7-9_14-4-15.png
 
Last edited:
Thanks everybody for help:) I think i got ign 2 working by cleaning the bulkhead connector does anybody know what this is? It takes power from fuse box BEFORE fuses.
20220710_153806.jpg
20220710_153759.jpg
 
jeppe said:
Question once More... Does anybody know is these wired correctly. Black and Orange switches places and 2 blacks goes for nothing. Thanks In advance :)

View attachment 1715954802

View attachment 1715954803
Click to expand...
"Generally" no, not correct, but I've heard that some switches are color coded wrong/ different. "Does it work?" Normally orange goes to all dash dimmer controlled lighting, like the cluster, radio, shift quadrant, etc.

Normally Yellow is your "start" wire going from the key to the starter relay
 
Is this a genuine '71 Dart wiring harness? If so, it looks correct for the 1st five wires....yellow, black, double blue, brown, and red. After that it should be an orange. I see no double blacks on the end in my wiring diagram.
 
Some of you guys double check this, but it looks like a 1972 instrument panel wiring harness.
 
Okey thanks :eek: but now i have once again problem. When i put dash back together my turn signals No longer work. I have measure the turn signal relay and there is No power coming to it. Then i disconnected the under colum coupling and measured pins coming from steering wheel and there is No power also... Where should i Check next? I tried to Check on manual but didint find it and i think some wires are different color on 71 than 72 wich manual i have. Sorry about so many guestions i just got the car and the wiring is kinda Off mess. And i noticed this connector next to wiper switch anyone know what it is for? The black and White with Brown connector.
20220713_172037.jpg
Thanks again :)
 
Updating the ignition switch question. The 71 and 72 ignition switch wire color codes are the same so you do have the original 71 wiring harness. The orange wires should mate with each other. The orange wire sends power to the gear selector display light on the column. There should be 2 red wires coming out of the column that connect to the 2 black wires from the instrument panel wiring harness. The red wires go to the key warning buzzer.
 
townsend said:
Updating the ignition switch question. The 71 and 72 ignition switch wire color codes are the same so you do have the original 71 wiring harness. The orange wires should mate with each other. The orange wire sends power to the gear selector display light on the column. There should be 2 red wires coming out of the column that connect to the 2 black wires from the instrument panel wiring harness. The red wires go to the key warning buzzer.
Click to expand...
okey thank you for that :)
 
okey i got the turn signals working again but now car only starts on neutral and not park. do i need to recenter stearing colum somehow? wicth i dropped before to get cluster out :eek:
 
You must log in or register to reply here.
-

Back
Top