Speedometer problem

[Barnett]

The mph dial needle is not moving. I thought this was because I fried part of the circuitboard while installing LEDs in place of the orange lights that light the dials. So I ordered a new set of clocks, took the circuitboard out of that, installed LEDs without touching the motor that turns the needle and now the needle won't move at all, whereas before it would sort of tick when accelerating, and just stay at wherever it landed when I turned the engine off.

Could this be as a result of 2 of the LEDs I put in place not working? They are the ones that are for the fuel and temperature gauges and are nowhere near the needle, but if it's all connected I suppose it could have an effect?

Any ideas?

 

[GrahamS]

assume your speedo sensor is abs driven and not gearbox mount.

Unless you've fried the circuit board and got it too hot then no.

 

[Barnett]

I couldn't tell you how my speedo sensor is driven I'm afraid. It's a 2003 dci 80 if that gives any clue.

I thought it was possible that I'd fried part of the first one, since i took out the motor to make it easier to access the LEDs, but I didn't touch it this time. I really haven't got a clue.

 

[Ianboom]

Have you got the LEDs in the correct way round? Have you tried taking them back out to see if the problem goes away? Been a long time since I did electronics at college, but they are a diode and may affect the delicate electronics on the display!?

 

[Barnett]

Have you got the LEDs in the correct way round? Have you tried taking them back out to see if the problem goes away? Been a long time since I did electronics at college, but they are a diode and may affect the delicate electronics on the display!?

I'm not sure, 2 of them aren't lit (one either side of the multi display in the middle) but each of their corresponding LEDs are, and they are in sequence with one another, so I assume they must be the right way around. They are technically SMDs, but I assume the D still stands for diode so that could be the reason. I know for a fact that all but one are the right way around, I'm unsure about the final one as I've never been able to make it lit. However, the SMD next to it didn't light when it was facing the other way so I can only assume it is the right way around.

It seems strange that the speed needle is the only thing affected.

As I said in the original post, previously the needle still moved, just not in concordance with my speed, now it does nothing. I suppose this could be because an extra SMD isn't working compared to before. I've tried resoldering new SMDs in place to no avail, so I'm not really sure what to do.

 

[GrahamS]

There is a little bit missing from the corner on the negative side, just make sure it's in the same place as the one you took off.

 

[Barnett]

I couldn't get my camera (on my phone) to focus in that close to see which way around they were before taking anything off. As I said I'm sure all but one are correct, since they were working and lit in that position. The unaccounted for one I believe is the right way around as the one next to it didn't work when it was orientated the other way.