Speedometer Not working

[dluszcz]

I'm new to the site. Just bought a 95 Civic DX 5 speed from my mechanic. The speedometer was not working but would occassionally start working about 20 minutes after driving it. He replaced the VSS and I unplugged it and checked it out. Still looks good. No corrosion.

Bought a gauge cluster out of a 92 Civic EX automatic. All the other gauges work except for the speedometer. In the old gauge cluster, even the odometer didn't work. My question is, what else can it be?

Another bad cluster? A bad VSS? Which of the 3 wires is the speedo wire so that I can run a new wire from the VSS directly to the back of the cluster or is that even advised?

I searched a lot of the speedo threads in here and after 2 hours, I'm at a stand still. I even unplugged my battery for 20 minutes and still no speedo.

 

[RonJ]

Does the CEL work and is it on? If so, check whether code 17 is thrown.

 

[dluszcz]

No check engine light. I know it works because my mechanic installed a turbo but didn't upgrade the MAP sensor. The 1st day I took it for a spin, the CEL came on and the RPMs started jumping around. I shut it off and restarted it and the CEL went off.

 

[RonJ]

Use a multimeter to check the wire that runs between the VSS and speedometer for an open or short. The VSS wire pins to B2 in connector B of the cluster, so also check those terminals in the connector and cluster for damage.

 

[dluszcz]

When my mechanic replaced the speed sensor, the speedo still didn't work. They checked the wiring and had continuity all the way up to the gauge cluster. That is why he told me that I'll have to buy a new one.

Every other function except the speedo works, as far as I can tell. I haven't had it warmed up yet but I would guess the temp gauge will work as well.

 

[RonJ]

When my mechanic replaced the speed sensor, the speedo still didn't work. They checked the wiring and had continuity all the way up to the gauge cluster. That is why he told me that I'll have to buy a new one.

Every other function except the speedo works, as far as I can tell. I haven't had it warmed up yet but I would guess the temp gauge will work as well.

I think it's an intermittent wire problem, which will make it tricky to find. As you mentioned, however, the problem typically lies with the VSS connector. Some people cut it off and replace it with one from a junk yard.

 

[dluszcz]

I'm not sure which wire I need to check. I looked at the diagram and it should be the yellow/blue wire. I hooked up a multi meter and turned the dial to every possible one on it and nothing. I'm guessing it's a wiring issue.

I noticed that when I pulled the cluster out to check it, the lights didn't work when I put it back in. I had to jiggle the wires and then I got it to come on. Could that mean it's just bad luck and I have a 2nd bad cluster?

On the VSS, there are 3 wires coming out. They are yellow/white, yellow, and black. At least that's what they look like using a flash light outside. I have no problem cutting the right wire and running a new wire to the proper pin position in the wiring harness going into the gauge cluster.

 

[RonJ]

If you look at the circuit diagram, you'll see that the wire of interest is Yel/Wht at the VSS and changes to Yel/Blu at the cluster.

You need to check for continuity between both ends of the wire (VSS to Cluster). The multimeter is set to measure resistance or continuity for the test. Post a picture of your multimeter if you want to know how to set it.

 

[Hecz]

this happen to me, and what resolve the problem was a blown fuse that was in the same circuitry ass the vss. i say check a your under dash fuse box closely. might be that.

 

[dluszcz]

I have to go to work so I will have to finish this tomorrow. I will take a pic of the multi meter and post it so I can set it up correctly and check.

 

[dluszcz]

Called the mechanic I bought the car from. He put a used VSS in but checked the ohms on it before installing it. Had power going to the input but didn't check the output from the ECU. He checked the wire from the harness and from the gauge cluster, but not from the ECU. His guess is that since I swapped gauge clusters and everything works except the speedometer, the ECU could be bad. Is it possible that it could be that simple? I'm just wondering because I found a ton of threads on the ECUs but most are for chipping them. Is it worth a $50 used ECU to see if that gives me a speedo?

 

[RonJ]

No, if the wire between the ECU and VSS were bad, it would throw code 17. The ECU has nothing to do with the speedometer, so focus on the unique branch of the VSS circuit running to the speedometer.

 

[dluszcz]

Ron,

I cannot post attachments. So, I have to describe the multimeter to you. It is a Sperry SP-10A. I have a positive and a negative wand. For the Ohm setting, I have 3: RX1, RX10, and RX100. For the ACV and DCV settings, I have 4: 500, 250, 50, and 10. For the DCA setting, I have 250m. And, it has the Battery test, 9V and 1.5V.

I ran a fresh wire from the VSS to the speedometer wire in the gauge cluster. I didn't drill through the firewall or anything, I just tapped into the yellow/white wire under the hood, ran it along the firewall, up through the fender and through the driver's side window. I physically cut the yellow/blue wire in the gauge cluster about 3 inches from the end of the harness and hooked up the fresh wire to the gauge cluster.

Took the car for a drive and still not working.

 

[RonJ]

Ron,

I cannot post attachments. So, I have to describe the multimeter to you. It is a Sperry SP-10A. I have a positive and a negative wand. For the Ohm setting, I have 3: RX1, RX10, and RX100. For the ACV and DCV settings, I have 4: 500, 250, 50, and 10. For the DCA setting, I have 250m. And, it has the Battery test, 9V and 1.5V.

Use the RX1 setting to measure resistance/continuity.

I ran a fresh wire from the VSS to the speedometer wire in the gauge cluster. I didn't drill through the firewall or anything, I just tapped into the yellow/white wire under the hood, ran it along the firewall, up through the fender and through the driver's side window. I physically cut the yellow/blue wire in the gauge cluster about 3 inches from the end of the harness and hooked up the fresh wire to the gauge cluster.

Took the car for a drive and still not working.

Still no CEL code 17? If so, unsplice the Yel/Blu wire and then use your multimeter to measure DCV voltage to body ground from the cut end of the Yel/Blu wire attached to the cluster. Do measure about 5V when the key is turned to ON(II)? Set the multimeter to DCV 10 for this measurement.

 

[dluszcz]

When I do the test, do I need to have the wire unspliced for the ohm test too or can I just test the ohms at the VSS where I exposed the wire on the yellow/white wire?

 

[RonJ]

When I do the test, do I need to have the wire unspliced for the ohm test too or can I just test the ohms at the VSS where I exposed the wire on the yellow/white wire?

Since you ran a new wire, I don't see a need now for the Ohm test. Did you carefully inspect the B2 terminals in the cluster and connector B? If so, do the voltage test.

 

[dluszcz]

Houston, I think we found the problem. No Volts and no Ohms.

Since I had to drive the car, I removed the fresh wire. The tests were done with the factory wires. I didn't want to go any long distance with the wire going through the window.

For the Ohm test, I put the positive in the VSS and the negative in the harness. Nothing.

I already unspliced the wire back together for the Ohm test and the car key was turned to II.

For the DCV voltage, I put the positive in the harness and touched the negative to the frame where the gauge cluster screws into. I also touched just about anything I could find that was metal under the dash and no voltage.

I'm assuming that the VSS is bad and that I must go on the hunt for another one.

Unless I did the tests wrong. I don't use this very often and usually to test batteries.

 

[RonJ]

Houston, I think we found the problem. No Volts and no Ohms.

For the Ohm test, I put the positive in the VSS and the negative in the harness. Nothing.

Tell me exactly what each meter probe is touching for this test.

I already unspliced the wire back together for the Ohm test and the car key was turned to II.

The Ohm test does not require the key to be on.

For the DCV voltage, I put the positive in the harness and touched the negative to the frame where the gauge cluster screws into. I also touched just about anything I could find that was metal under the dash and no voltage.

What do mean by harness? You need to meter the cluster side not the wire harness side for voltage.

I'm assuming that the VSS is bad and that I must go on the hunt for another one.

If the VSS were bad, you'd almost surely have code 17.

Unless I did the tests wrong.

I think the tests may have be done incorrectly.

 

[dluszcz]

For the Ohm test, I unplugged the harness from the VSS.
I put the red probe on the yellow/white wire prong.
I put the black probe on the yellow/white wire prong in the harness that is no longer connected to the VSS. I was touching the metal on both ends which should have completed the circuit. This is only the 2nd time I've measured for Ohms. The 1st time was yesterday. If my mechanic states that he got an Ohm reading each time he tested both VSS's, I'm certain that I must be performing the Ohm test incorrectly.

We have Voltage. I looked a little deeper and I don't believe that the cluster was mounted on a metal base that was attached to the frame. I plugged the harness back into the gauge cluster. I touched the red probe to the wire prong on the clip. I touched the black probe to the door hinge and I now have a reading of 7.5V. You said it should be around 5V. Is that a problem?

 

[RonJ]

For the Ohm test, I unplugged the harness from the VSS.
I put the red probe on the yellow/white wire prong.
I put the black probe on the yellow/white wire prong in the harness that is no longer connected to the VSS. I was touching the metal on both ends which should have completed the circuit. This is only the 2nd time I've measured for Ohms. The 1st time was yesterday. If my mechanic states that he got an Ohm reading each time he tested both VSS's, I'm certain that I must be performing the Ohm test incorrectly.

You did the continuity test incorrectly. You would unplug the VSS connector and cluster connector B. You would then touch one meter probe to terminal B2 in the cluster wire harness connector and the other probe to the Yel/Wht wire terminal in the VSS wire harness connector. But skip this test for now (see below).

We have Voltage. I looked a little deeper and I don't believe that the cluster was mounted on a metal base that was attached to the frame. I plugged the harness back into the gauge cluster. I touched the red probe to the wire prong on the clip. I touched the black probe to the door hinge and I now have a reading of 7.5V. You said it should be around 5V. Is that a problem?

Now reconnect cluster connector B and unplug the VSS connector. Turn the key to ON(II) and measure voltage at the Yel/Wht wire terminal of the VSS wire harness connector. Do you again measure 7.5V to body ground?