alsamrob4

Had my odometer gears repaired by a reputable shop in December. They also repaired/reflowed the PCB board. Just got around to installing it today. The speedometer doesn't work at all now. I got no codes on the Durametric, checked fuse 16 and 18. The tach works, and the gauge lights up when lights are on.
Everything I've read points to an internal issue with the speedo.
Am I missing anything else to check?

pp000830

I would clean the plug connector on the back of the clock and the wiring harness plug for the clock with spray electronic cleaner (CRC QD electronic cleaner spray for example,
I would look over the pins and socket on the connector to make sure none of the pins are damaged.
If none of the warning/status lights light up when the ignition is turned on and your car has no related modifications I would think the problem may be a common negative connection inside the clock.

Beyond this, I would have the guys who did the work test the clock.
I did the odometer fix at my kitchen table where I inspected and reheated any suspect connections. Since you paid someone to service the clock I would have them look at it before moving forward with any other repair options.

Andy

jay@EZimmoblock.com

By not working do you mean the needle doesn't move at all?
A number of devices in the car use the speed signal (Cruise control, spoiler controller, etc), so you might want to check and see if they are still working.
Have a look here for troubleshooting info. A couple quick checks with a voltmeter might help find the problem.

alsamrob4

Thanks for the input.

Andy, the pins look clean.


Jay, yes, the needle does not move all. The spoiler warning light did not go off, and the spoiler did not rise or lower as I drove. No other warning lights. Does that add anything to the troubleshoot?

I need a co pilot to do the voltmeter test, so that will have to wait until tomorrow.

alsamrob4

Jay, is there a way to test at the speedometer plug (ie the signal the speedometer should be getting) or does the OBD test accomplish the same thing?

jay@EZimmoblock.com

Yes, you can use a voltmeter to read AC volts on Speedo pin 4 to ground , pin 3. At all speeds, you should read approx half the running battery voltage. Don’t worry too much about the actual value, you’re testing for the presence of a signal. I have a feeling though, the problem is inside the Speedo, since the problem started after it was opened up and worked on. But it’s an easy test, worth doing to rule out a wheel sensor problem. Then move on to testing the “A” signal at the OBD2 port. Does
cruise control work?

alsamrob4

Thanks. Is there a diagram of the pins available? How do i determine which is pin 3 or 4?

I didn’t try the cruise control but will tomorrow.

jay@EZimmoblock.com

Pin 4 is the green wire. Brown is ground. Make the measurement with the Speedo connected.

alsamrob4

Excuse my inexperience and maybe this shows I shouldn’t do this but how do I test the output at the plug if the Speedo is connected?

ToreB

The speedometer harness connector has a cap that clips on. Unclip, open and place meter probes on the internal metal pins.
Be sure to not remove the connector from the speedo without the cap on, the wires and pins are then loose and can come out. It could be a good idea to note which wire colour that goes where.
Cheers,
Tore

jay@EZimmoblock.com

You beat me to it Tore! Here's a pic of what you'll see back there. If the wires fall out, put them back in as shown:



The tricky part will be clipping onto the pins, then installing the speedo and then driving. If you don't have test leads small enough to safely clip onto the exposed pins you can always strip back some insulation on the wires outside of the plug to give you more wire to clip to and tape them up when done.

alsamrob4

Thank you Tore and Jay. Does Durametric measure speed in the Actual Values mode?

alsamrob4

The cruise control didn't work, but to be honest I'm not sure it did before this issue. I didn't test the plug because I don't have clips for my multimeter, nor the OBDII port because mine was numbered differently and I wasn't sure which ports to try. The numbers start at "1" in the lower left with 1-9 on the left hand side and then 10--16 on the right starting on the lower right.

I really appreciate you guys having the patience to guide me through this.

jay@EZimmoblock.com

It's a little hard to see the pin numbers. Should be numbered like this:

alsamrob4

Got it. I’m going to need a better multimeter. Does the absence of the operability of the cruise shed any additional light?