speedometer inoperative

[bastianshaw]

No, they don't run on the same motor or anything. The speedo motor has its own output from the odometer, they have nothing to do with each other.

thats interesting because when my speedo fails so does my odo, they work or do not work at the same times.

[nando]

then it's the signal to the instrument cluster and not the speedo/odo itself.

[bastianshaw]

then it's the signal to the instrument cluster and not the speedo/odo itself.

so i dont need to soder the board/speedo?
its a dif signal issue? thayt sux cuz I checked the diff plug and it seemed ok

[nando]

it's almost always the wires and not the plug or sensor.

[bastianshaw]

that wire is a serious PITA to trace even w the exhaust off and shielding removed on a lift I couldnt see it, pointers?

[agent]

thats interesting because when my speedo fails so does my odo, they work or do not work at the same times.

then it's the signal to the instrument cluster and not the speedo/odo itself.

I have to respectfully disagree here nando. I am not convinced my issue is signal-related since another cluster (which I sold to another forum member and last I heard was still working flawlessly) did not exhibit the same behavior as the (original) one in there now - which is the same thing that's happening to bastianshaw.

I am admittedly clueless when it comes to electrical and wiring. However based on my very limited experience with this issue, if you can try another known good working cluster in there, that would be where I'd start.

[bastianshaw]

I have to respectfully disagree here nando. I am not convinced my issue is signal-related since another cluster (which I sold to another forum member and last I heard was still working flawlessly) did not exhibit the same behavior as the (original) one in there now - which is the same thing that's happening to bastianshaw.

I am admittedly clueless when it comes to electrical and wiring. However based on my very limited experience with this issue, if you can try another known good working cluster in there, that would be where I'd start.

Agent thnks for your response, the problem is that this is on a very low milage car and swapping to a different cluster would kill alot of the value of the car,it suz because EVERYTHING else works its just this damn intermittent speedo, I have pulled the cluster and checked the plugs, they were in tight, I was planning on sodering the board or having gregs ///m do it. Now I dont know what to do.

[nando]

I have to respectfully disagree here nando. I am not convinced my issue is signal-related since another cluster (which I sold to another forum member and last I heard was still working flawlessly) did not exhibit the same behavior as the (original) one in there now - which is the same thing that's happening to bastianshaw.

I am admittedly clueless when it comes to electrical and wiring. However based on my very limited experience with this issue, if you can try another known good working cluster in there, that would be where I'd start.

So the cluster worked in your car at some point, and definitely works in another car? that doesn't mean your car doesn't have a bad speedo signal. actually, it almost certainly means that's the problem, because a broken VSS wire from the diff can cause the speedo to work some of the time, or can fail suddenly.

Unless you swapped the cluster you sold into your car today, and it worked flawlessly without ever shutting down, you can't use that as evidence to say the VSS wire isn't broken.

The motor that drives the odometer is totally seperate from the speedo motor. They have their own outputs from the uaf chip, but there is only one vss input to the uaf chip.

it's possible it could be a bad connection inside the cluster, but the VSS wires from the diff breaking is such a very common problem, and it's so easy to fix, it's definitely the best place to start.

[agent]

Agent thnks for your response, the problem is that this is on a very low milage car and swapping to a different cluster would kill alot of the value of the car,it suz because EVERYTHING else works its just this damn intermittent speedo, I have pulled the cluster and checked the plugs, they were in tight, I was planning on sodering the board or having gregs ///m do it. Now I dont know what to do.

To clarify, I didn't mean permanently. I just meant long enough for you to know whether or not a different cluster was doing the same thing. If the odo isn't working 100% of the time with the cluster that's in it currently, then the mileage isn't 100% accurate anyway.

[agent]

So the cluster worked in your car at some point, and definitely works in another car?

No... the original cluster was/is intermittent. It was out of the car for nearly a year while I was waiting for the Garagistic Moto gears (in conjunction with all the other work I was doing). I had swapped in another cluster during that time which worked perfectly - the one I sold to another forum member.

[Gregs///M]

You guys with the odometer/speedometer failing at the same time,

Primary source of the problem that I would check first is the input into the cluster. The wire itself feeds into the white connector behind the cluster. The wire is brown/red.

Solder joint cracks are very common on the header pins that are soldered to the main board. So I would disassemble the cluster, access the main board, and solder the joints from the white connector. Inspect under magnification or just re-flow solder on all of them.

You can put the car on jack stands and start it up, place into gear and get those rear wheels spinning (does not need to be fast.) Check for speed signal at the brown/red wire at the cluster. You should see 1.5-6V AC, digital multimeter should be set to AC volts (pulsating current.) If you see voltage, this is verification the VSS is indeed at the cluster and the problem lies inside the cluster. Then check the main board.

For you guys with EITHER the speedometer OR odometer failing,

Speed signal is definitely input into the cluster or else both gauges would fail. Odometer not working would indicate bad odo gears. Speedo failing would indicate blow fuse, cracked solder joints on main board still, or cracked solder joints on the speedo circuit board. There are some electrical components known to fail on the speedo as well, particularly capacitors.

Hope that clears things up and get's you guys on the road to working clusters.

[Will_NZ]

the VSS wires from the diff breaking is such a very common problem, and it's so easy to fix, it's definitely the best place to start.

^This!

The twin wire from the plug on the diff to the body gets brittle and eventually breaks. This is the most common cause of the speedo/odo failing.

The best thing is to replace the last 300-400mm of the wiring to the diff plug.