thomo8568 Posted April 21, 2014 Share Posted April 21, 2014 (edited) Used the car this weekend for the first time in a few weeks and the speedo has stopped working. It's still adding miles to the odometer, and the rest of the dash seams ok. So I'm thinking its eather the speedo or the speed converter. My speed converter is wired in to the back of the speedo. I'm not sure if the speedo would have been changed for this to work? Is the any way of testing the speedo? Edited April 21, 2014 by thomo8568 (see edit history) Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted April 21, 2014 Share Posted April 21, 2014 By any chance was you O/D OFF light flashing on your instrument cluster? Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 No I don't think it was on. Not that I noticed anyway. Will check next time I take it out. What would it mean if the OD light was on? Cheers Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 22, 2014 Share Posted April 22, 2014 I agree that it's likely to be either the speedo dial or the speed converter, and my money's on the converter (or at least the electrical connections to/from it). Try wiring the speedo back to stock and see if the speedo works again. Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 I agree that it's likely to be either the speedo dial or the speed converter, and my money's on the converter (or at least the electrical connections to/from it). Try wiring the speedo back to stock and see if the speedo works again. I was thinking of removing the converter, but I've never seen one wired like this. So wasn't sure if anything would have been done to the speedometer for it to work. But can give it a go. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 22, 2014 Share Posted April 22, 2014 For the purposes of the test, you should be able to connect the blue with red stripe wire from the speed sensor (the converter will take this as an input) direct to pin 5 of the speedo connector block. Disconnect the converter so you haven't got competing signals down one wire. Depending on the details of the converter, this might stop the odometer from working (and thus generate an error code at the ECU), but it'll be enough to see if your speedo is basically sound. Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 For the purposes of the test, you should be able to connect the blue with red stripe wire from the speed sensor (the converter will take this as an input) direct to pin 5 of the speedo connector block. Disconnect the converter so you haven't got competing signals down one wire. Depending on the details of the converter, this might stop the odometer from working (and thus generate an error code at the ECU), but it'll be enough to see if your speedo is basically sound. My converter isn't connected in to the loom, it's connected straight on to the speedo. So I'm unsure if the speedo would work if I removed, it as I would have thought the speedo circuit would have been changed in some way for it to work. The converter is at the bottom with the 3 turn switches. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 22, 2014 Share Posted April 22, 2014 Hmm, unusual. Sounds like the converter is some kind of piggy-back device. I'd still try removing it and see what happens. If the speedo then works, you've proven it's the converter at fault. If the speedo still doesn't work, it doesn't prove anything because as you said, the speedo's circuit *might* have been altered (seems very unlikely though). Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 Hmm, unusual. Sounds like the converter is some kind of piggy-back device. I'd still try removing it and see what happens. If the speedo then works, you've proven it's the converter at fault. If the speedo still doesn't work, it doesn't prove anything because as you said, the speedo's circuit *might* have been altered (seems very unlikely though). Will give it a go removing it. As you say it can't hurt. The reason I think the speedo has been altered is the solder on one of the resistors looks different to the rest. Anyone one got a photo of the speedo board and resistors? Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted April 22, 2014 Share Posted April 22, 2014 No I don't think it was on. Not that I noticed anyway. Will check next time I take it out. What would it mean if the OD light was on? Cheers I have a similar problem, my speedo was like it had mechanical sticking. Now it doesnt work and I had to estimate the speed the other day. My OD/OFF light started flashing and a few forum searches related to the the speed sensor connection on gearbox and code 42... Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 I have a similar problem, my speedo was like it had mechanical sticking. Now it doesnt work and I had to estimate the speed the other day. My OD/OFF light started flashing and a few forum searches related to the the speed sensor connection on gearbox and code 42... Will have to check for codes later. But my OD lights isn't on so don't think it's the sensor, and my odometer is still counting up the miles. Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted April 22, 2014 Share Posted April 22, 2014 Will have to check for codes later. But my OD lights isn't on so don't think it's the sensor, and my odometer is still counting up the miles. OD - over drive not odometer I have an auto you must have a manual. My odometer works too. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 22, 2014 Share Posted April 22, 2014 Tayfun: your problem is probably caused by a failed output buffer in the odometer. You can probably connect the odo input to the odo output to fix this. I did a detailed description ages ago, let me see if I can find it... Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 OD - over drive not odometer I have an auto you must have a manual. My odometer works too. Mine is an auto also. My OD/off light isn't flashing so don't think its a code 42 error. My odometer is still working as well so don't think its a sensor. Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 Tayfun: your problem is probably caused by a failed output buffer in the odometer. You can probably connect the odo input to the odo output to fix this. I did a detailed description ages ago, let me see if I can find it... Do both the speedo and odometer have the same feed from the speed sensor? Thanks for all your help so far. Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 Can anyone confirm if this resistor is correct? As it looks like it may have been replaced. The one with the wire run under it. Quote Link to comment Share on other sites More sharing options...
Tayfun.tugra Posted April 22, 2014 Share Posted April 22, 2014 Tayfun: your problem is probably caused by a failed output buffer in the odometer. You can probably connect the odo input to the odo output to fix this. I did a detailed description ages ago, let me see if I can find it... Mine is an auto also. My OD/off light isn't flashing so don't think its a code 42 error. My odometer is still working as well so don't think its a sensor. Ok cheers. sorry for the hijack Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 22, 2014 Share Posted April 22, 2014 Do both the speedo and odometer have the same feed from the speed sensor? Thanks for all your help so far. That's correct. I don't want to hijack the OP's thread any more, but if you want to open another thread I'll happily go into more detail. Quote Link to comment Share on other sites More sharing options...
thomo8568 Posted April 22, 2014 Author Share Posted April 22, 2014 That's correct. I don't want to hijack the OP's thread any more, but if you want to open another thread I'll happily go into more detail. It's ok this is my thread. Quote Link to comment Share on other sites More sharing options...
stevie_b Posted April 22, 2014 Share Posted April 22, 2014 It's ok this is my thread. Ah, it's been a long day! So yes, they have the same feed. The speed signal first goes to the speedo, which then re-broadcasts it to the odometer. The odometer uses it, buffers the signal (it's this buffer that often gives up and causes error code 42, speed sensor error) and re-broadcasts it to the ECU. The speedo's at the start of the chain, and the ECU's at the end of the chain. Quote Link to comment Share on other sites More sharing options...
LOGIE Posted March 21, 2016 Share Posted March 21, 2016 Thomo did you get to the bottom of this? I'm having same issue. Quote Link to comment Share on other sites More sharing options...
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