Fixing borked gauges - it's not the cluster (wiring)
08-22-2013, 04:34 PM
#1
Fixing borked gauges - it's not the cluster (wiring) Tl;dr how many ohms is too many for a ground?
This started after my fuel pump swap. The fuel gauge on my cluster started reading always empty so I thought I broke the arm on the sending unit. Thankfully I did the trap door mod, so I was able to rip the sending unit back out quickly. But I saw the arm was not broken, so I was like :wtf:
I reinstalled it, same problem.
I replaced the cluster. Same problem. Ok so I think it's the wiring, but I'll get around to fixing it later (I hurt my back real bad fairly recently and was recovering all summer). Well I go to start looking at it and now not only does the fuel gauge read empty, but the tach reads 5000 rpm at idle and all the other gauges don't work. Fuel gauge reads empty, battery volts and oil pressure read empty, speedometer always says 0 mph and temperature gauge always reads 1/4. The idiot lights do work though when I first turn the key.
So I checked the two grounds. Black wire in pin C4 is ok. Black/white wire in pin D8 is ok key off (2 ohms to chassis), but is like 30 ohms with the key on.
So I got a piece of junk wire, stripped some insulation off it and the black/white wire and grounded the junk wire to the chassis. I also wrapped some bare wire from the junk one around the black/white wire and it's now like 13-15 ohms with the key on (instead of 30). Gauges still don't work though.
Do I need to get the ohms lower for it to be a good ground? Or is my problem likely something else? I tested all the other pins and like I said the other ground wire is ok, the other relevant pins (like oil pressure) read battery voltage with the key on... Oh and this is the only wiring diagram I could find, sorry:
This started after my fuel pump swap. The fuel gauge on my cluster started reading always empty so I thought I broke the arm on the sending unit. Thankfully I did the trap door mod, so I was able to rip the sending unit back out quickly. But I saw the arm was not broken, so I was like :wtf:
I reinstalled it, same problem.
I replaced the cluster. Same problem. Ok so I think it's the wiring, but I'll get around to fixing it later (I hurt my back real bad fairly recently and was recovering all summer). Well I go to start looking at it and now not only does the fuel gauge read empty, but the tach reads 5000 rpm at idle and all the other gauges don't work. Fuel gauge reads empty, battery volts and oil pressure read empty, speedometer always says 0 mph and temperature gauge always reads 1/4. The idiot lights do work though when I first turn the key.
So I checked the two grounds. Black wire in pin C4 is ok. Black/white wire in pin D8 is ok key off (2 ohms to chassis), but is like 30 ohms with the key on.
So I got a piece of junk wire, stripped some insulation off it and the black/white wire and grounded the junk wire to the chassis. I also wrapped some bare wire from the junk one around the black/white wire and it's now like 13-15 ohms with the key on (instead of 30). Gauges still don't work though.
Do I need to get the ohms lower for it to be a good ground? Or is my problem likely something else? I tested all the other pins and like I said the other ground wire is ok, the other relevant pins (like oil pressure) read battery voltage with the key on... Oh and this is the only wiring diagram I could find, sorry:
08-22-2013, 10:28 PM
#2
With the fuel gauge disconnected it will read empty. You need to verify you have power at the power wire going to the pump. KOEO will determine that.
If you do then also test the pump at the pump and OHM it out between the ground wire and the power wire. Whatever those ohms are that will tell you how much gas is in the car.
If all of that is well then you know the power and grounds are good at the pump and therefore its your gauge.
Im thinking you have bcm issue or wire relations to the bcm or under dash connectors c210 c220 c230.
For 2 clusters to be bad I dont see happening.
Why did you swap clusters anyhow? Why and when did this all happen?
what year is this your working on?
If you do then also test the pump at the pump and OHM it out between the ground wire and the power wire. Whatever those ohms are that will tell you how much gas is in the car.
If all of that is well then you know the power and grounds are good at the pump and therefore its your gauge.
Im thinking you have bcm issue or wire relations to the bcm or under dash connectors c210 c220 c230.
For 2 clusters to be bad I dont see happening.
Why did you swap clusters anyhow? Why and when did this all happen?
what year is this your working on?
08-23-2013, 10:22 PM
#6
With the fuel gauge disconnected it will read empty. You need to verify you have power at the power wire going to the pump. KOEO will determine that.
If you do then also test the pump at the pump and OHM it out between the ground wire and the power wire. Whatever those ohms are that will tell you how much gas is in the car.
If all of that is well then you know the power and grounds are good at the pump and therefore its your gauge.
Im thinking you have bcm issue or wire relations to the bcm or under dash connectors c210 c220 c230.
For 2 clusters to be bad I dont see happening.
Why did you swap clusters anyhow? Why and when did this all happen?
what year is this your working on?
If you do then also test the pump at the pump and OHM it out between the ground wire and the power wire. Whatever those ohms are that will tell you how much gas is in the car.
If all of that is well then you know the power and grounds are good at the pump and therefore its your gauge.
Im thinking you have bcm issue or wire relations to the bcm or under dash connectors c210 c220 c230.
For 2 clusters to be bad I dont see happening.
Why did you swap clusters anyhow? Why and when did this all happen?
what year is this your working on?
08-24-2013, 11:27 PM
#7
so you ohmed the wire from the cluster to the pump?
what were your specs?
ITs only 1 wire which is purple.
Did you check the ground for the cluster and the pump?
Its mounted on the floor board under the driver seat. It has 2 wires going to it and both grounds of course.
what were your specs?
ITs only 1 wire which is purple.
Did you check the ground for the cluster and the pump?
Its mounted on the floor board under the driver seat. It has 2 wires going to it and both grounds of course.
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08-27-2013, 01:52 PM
#8
so you ohmed the wire from the cluster to the pump?
what were your specs?
ITs only 1 wire which is purple.
Did you check the ground for the cluster and the pump?
Its mounted on the floor board under the driver seat. It has 2 wires going to it and both grounds of course.
what were your specs?
ITs only 1 wire which is purple.
Did you check the ground for the cluster and the pump?
Its mounted on the floor board under the driver seat. It has 2 wires going to it and both grounds of course.
08-27-2013, 10:19 PM
#9
Do you have a full tank?
Do you have power at the pump? The gray wire should have koeo power to the pump.
black wire should have a good ground going to the pump. use battery to check for these power and grounds. Make sure you check the batt. voltage first so you have a reference for voltage.
Next leave the pump disconnected and leave a voltmeter on the gray wire and crank the car over and see if you have a constant 12v +
To test back to the gauge, ground the purple wire on the body side of the connector back toward the gauge (key ON). The gauge should read empty. With the connector unplugged and no ground applied, the gauge should read full.
Do you have power at the pump? The gray wire should have koeo power to the pump.
black wire should have a good ground going to the pump. use battery to check for these power and grounds. Make sure you check the batt. voltage first so you have a reference for voltage.
Next leave the pump disconnected and leave a voltmeter on the gray wire and crank the car over and see if you have a constant 12v +
To test back to the gauge, ground the purple wire on the body side of the connector back toward the gauge (key ON). The gauge should read empty. With the connector unplugged and no ground applied, the gauge should read full.
Last edited by robsquikz28; 08-27-2013 at 10:45 PM.
08-31-2013, 10:17 PM
#12
Sounds like a half *** job to me and make a mess for more ****.
You need to see if you have power from the pcm to the gauges.
Ohm the wires to the pcm to the cluster.
U had to burn wires or touch wires somewhere from all of your swaps.
Causing them to go haywire like that is a wire or wires issue. Even going to different gauges im betting you will still have issues.
You need to see if you have power from the pcm to the gauges.
Ohm the wires to the pcm to the cluster.
U had to burn wires or touch wires somewhere from all of your swaps.
Causing them to go haywire like that is a wire or wires issue. Even going to different gauges im betting you will still have issues.
08-31-2013, 10:29 PM
#13
Sounds like a half *** job to me and make a mess for more ****.
You need to see if you have power from the pcm to the gauges.
Ohm the wires to the pcm to the cluster.
U had to burn wires or touch wires somewhere from all of your swaps.
Causing them to go haywire like that is a wire or wires issue. Even going to different gauges im betting you will still have issues.
You need to see if you have power from the pcm to the gauges.
Ohm the wires to the pcm to the cluster.
U had to burn wires or touch wires somewhere from all of your swaps.
Causing them to go haywire like that is a wire or wires issue. Even going to different gauges im betting you will still have issues.
08-31-2013, 10:40 PM
#14
u Need to ohm them wires as well.
There are other wires that go to the cluster from other ares.
It also gets power from interior fuses by the side of dash
You got to have wires loose or touching one another under the dash or near it.
Does it run rough at all or die out? We need more info on exactly this when this went bad and what was all changed out before this happened.
There are other wires that go to the cluster from other ares.
It also gets power from interior fuses by the side of dash
You got to have wires loose or touching one another under the dash or near it.
Does it run rough at all or die out? We need more info on exactly this when this went bad and what was all changed out before this happened.
08-31-2013, 10:58 PM
#15
u Need to ohm them wires as well.
There are other wires that go to the cluster from other ares.
It also gets power from interior fuses by the side of dash
You got to have wires loose or touching one another under the dash or near it.
Does it run rough at all or die out? We need more info on exactly this when this went bad and what was all changed out before this happened.
There are other wires that go to the cluster from other ares.
It also gets power from interior fuses by the side of dash
You got to have wires loose or touching one another under the dash or near it.
Does it run rough at all or die out? We need more info on exactly this when this went bad and what was all changed out before this happened.
08-31-2013, 11:02 PM
#16
so the only issue is cluster?
If thats the case unplug the fuel pump and see if the gauges work properly.
Or unplug the coolant temp sensor first and start the car and see what happens with the gauges.
You might even have a voltage issue coming from the alternator wiring to the interior connector that goes to the cluster. Might be loose and causing erratic gauges.
Tach wire you can disconnect as well and see what happens.. This is the white wire to the cluster or disconnect from the pcm.
You have to eliminate one circuit at a time and see if its the circuit or pcm related.
If thats the case unplug the fuel pump and see if the gauges work properly.
Or unplug the coolant temp sensor first and start the car and see what happens with the gauges.
You might even have a voltage issue coming from the alternator wiring to the interior connector that goes to the cluster. Might be loose and causing erratic gauges.
Tach wire you can disconnect as well and see what happens.. This is the white wire to the cluster or disconnect from the pcm.
You have to eliminate one circuit at a time and see if its the circuit or pcm related.
