silent running

A couple of problems that may be related...for a while now, I've had a bouncing speedo needle at very low speed, either in neutral or first. I have a 98 WRX with electronic clocks (or at least the odometer is digital). So I'm assuming that when it was delimited and converted back in 98 as a new import, it was an electronic box behind the dash that did the signal division rather than a cog box in line with a mechanical speedo cable.

Now the thing is, when I got it to repeat the bouncing needle trick whilst I was watching my Power FC readout, I could see that the bounce was repeated on the screen as well. I.e. it would seem that the fault is at the source of the signal, in the sensor in the gearbox. But where does the ECU take its speed signal from? Is it split off directly at source (i.e. one cable going to the speedo in the dash, the other going to the ECU), or is it fed first to the speedo, then back out again to the ECU? Or even the other way round, first to the ECU then out again to the speedo? The Power FC still reads in kph as well, even though the car's been showing miles and mph since it was imported back in 98.

Not that I mind taking my clocks out to have a look, but I suspect that I will find a conversion unit there that I will unplug and plug in again and I may well end up with the same problem. I just don't want to buy a new sensor if I don't need one.

The other thing, which I thought might be related is that I've got a loud irritating on and off squeak behind the dash which happens whenever I'm cruising and on a relatively constant throttle and speed. However, shaking the car by bouncing up and down or back and forth on the driveway will not trigger it at all. It only does it while actually driving at a constant speed. Gearchanges always trigger a chirp from behind the clocks. On engine braking or deceleration it NEVER makes a sound. Almost as if I had a mechanical speedo drive behind there that was locking tight when enging braking but squeaking every time it takes up drive or has very little torque acting on it? Which is totally mental seeing as I've supposedly got an electronic speedo?!

Now I'm confused. Help!

funkyspider

You'd better change your name to 'squeaky running' then

Sorry, couldnt resist.


I have a gentle tapping behind the dash, I'm sure its just a connector plug tapping on the plastic underside of the dash, but I sympathise coz it drives me nuts.

ticky

I have a 98sti speedo clock (not fitted yet) Their is a intec speed convertor wired into the back of the clock. The speedo sensor (gearbox end) I have is a 2 wire type, these 2 wires lead directly to the back of the clock. The intec speed convertor is spliced inbetween these wires. Then there single green/black wire that leads to the ecu. This wire is not spliced into the intec speed convertor.
Going by a thread on rs25.com thie green/black wire is the speed signal wire.

I will try to find the excat colour codes later as I am not at home atm.

Ticky

silent running

Squeaky running LOL

ticky I just checked it out and I have the same thing behind mine - an Intec speed convertor/delimiter. It's about the size of a packet of ****. It's getting dark now so it's hard to look at the loom properly, but it looks like there's a lot of black electrical tape in there, presumably to bodge up where the convertor was spliced in. I'll take it off and have a look at the wiring properly.

The back of my clock unit has three separate plugs that just go into it, no separarate wiring as such for just the speedo. But it'll be easy enough to track which wire has been spliced. Where does your single green black ECU wire come from? Before the splice, or after it, off the back of the clocks?

Either way, if the speedo's seeing the bounce, and the Power FC via the ECU port is seeing the bounce as well, most likely cause is the sensor itself. Unless the convertor is causing the bounce, sending a dodgy signal to the speedo and the ECU? And the Power FC reads out the speed in kph but it's the same numerical value as it shows in mph on the speedo. Therefore if I'm not wrong, the ECU feed must be taken off after the convertor?

ticky

Ive been working on trying to fit the later sti dash etc into my 95sti, just finished off seperating all the wires I need.

Mine is the same with 3 connector plugs.
If you look at the speedo clock as it is in the car, the connector on the rh side nearest the speedo face (180mph) has 13 pins.
Call this connector A.

B.The middle connector has 10 pins (1 is blank) so call it 9 pins '

C.The LH side connector has 13 pins (4 are blank) so call it 9 pins

Connector A wires start with:
pin 1: voilet (illumination)

pin 2: black wire (this wire comes directly from the speed sensor on the gearbox) But it has been cut in half near the connector. This is where 1 half of the black wire is joined to a grey wire off the intec speed convertor. The other half of the black wire is joined to a yellow wire off the intec speed convertor.

pin 3: green & black wire: I traced this directly to the ecu, no other wires joined to it. This is the speed signal wire.

pin4; White wire, this goes directly to the speed sensor in the gearbox.


Connect B.
Pin 7: black wire (earth) this has the black wire off the intec sc spliced into it.

pin 9: green & black wire (this is something to do with the temp gauge) according to rs25.com thread this wire should be green & white??. Anyway the red wire off the intec speed convertor is spliced into this green & black wire.
I am also going to use the green & black wire to power up the speedo clock (ign).

I am new to the elevtrical speedo sides of thing but as you say it could be either a faulty speedo sensor gearbox or the one built into the speedo.

Ticky

ticky

JDM V4 Harness: This is what the connector leads to on the gauge cluster
A1> BlU/WHT high beam indicator
A2> RED high beam indicator
A3> YEL door open, interior lights
A4> LTGRN ! symbol for parking brake
A5> RED/WHT CEL (now in red)
A6> BLK/WHT battery symbol/light
A7> BLK/BLU seat belt symbol/light
A8> GRN/WHT oil drip symbol/light
A9> BLU/RED open door warning/light
A10> WHT vehicle speed sensor 2
A11> GRN/BLK vehicle speed signal wire
A12> BLK vehicle speed sensor 2
A13> VIO illumination


B1> YEL/BLK clock
B2> GRN/WHT temp gauge
B3> BLK/RED temp gauge
B4> BLK ground
B5> -------
B6> BLK/GRN left turn indicator
B7> GRN/RED airbag symbol/light
B8> BLU/ORG open door warning indicator/light
B9> LTGRN/BLK right turn indicator
B10> GRN tach signal


C1> ORG/WHT illumination
C2> BRN/WHT fuel gauge
C3> RED/BLK low fuel warning light
C4> YEL/GRN hot "thing" warning light
C5> LTGRN/YEL ABS indicator/light
C6> BLU/YEL snow flake "HOLD" warning/indicator
C7> PNK ???
C8> WHT/BLK small lightbulb housing, with no transparent indicator
C9> YEL/RED I/C Spray indicator light
C10> BRN/RED small lightbulb housing, with no transparent indicator
C11> ------ small lightbulb housing, with no transparent indicator
C12> WHT/GRN temp gauge
C13> YEL/GRN clock


I just copied & pasted from the thread on rs25.com just incase.

I would be interested to know which wires your intec speed convertor is spliced into?

& if you could check B2 pin as mine is green & black not green & white as stated above.

Thanks Ticky

silent running

Wow what an answer! I'd already given up on it and put everything back seeing as it was getting very cold out in the car. But I think I might tackle it again and see what I can find out in the daylight.

I think you've understood perfectly what I'm trying to get at here - rare on Scoobynet LOL. It does seem as if the fault could be with either the clock unit itself internally, or the speedo sensor. The fact that the ECU is seeing the bounce as well as the speedo needle is neither here nor there; as you've worked out, the speedo signal goes into the clocks then back out again to feed the ECU and is not teed off anywhere beforehand, which would allow us to maybe rule out the clocks.

I think this is one of these things where I'll just have to replace my speed sensor and see if it cures it. If it doesn't then I'll know it's a clock problem.

silent running

Well I've found the squeak! I've been driving around the block with no clocks, no under-dash, no centre console or fascia, no transmission tunnel gubbins, nothing, and STILL it squeaked. Then I got my wife to listen from the outside and guess what, it was just as loud in the engine bay. A bit of to-ing and fro-ing around the driveway and the problem was revealed as the dogbone mount on top of the gearbox! It must be squeaking at the bulkhead end and this is vibrating in the cabin. No wonder I couldn't pin down the exact location, it must have been all over the bulkhead.

Now just got to have a look at those wires for you.

Oh and btw, for future reference, the ECU definitely does depend on the clocks for its speed signal. As soon as I drove around without them plugged in, the speed readout on the Power FC said zero, although interestingly revs still showed, meaning the rpm signal must be teed off to the ECU before it gets to the clocks.

ticky

Well I am glad you managed to trace down the squeak.

I was initially worried about the speed signal from the later clocks not being compatible with my 95sti ecu.
The last thing I wanted was to go ahead fit the clocks, dash etc and then find out that the ecu would go into limp mode.

Plus i was interested in knowing any possible future problems, causes with this new dash setup.

Ticky

silent running

Well I was able to drive around at whatever speed I wanted, although I didn't use much in the way of revs. Presumably the Power FC doesn't have a limp home mode.

Looking at the bodged up wires, the convertor device has four wires coming out of it, black and red which went off down to the centre plug and are presumably for positive and ground; also a yellow and grey which seem to be the signal wires, the yellow goes to a black with silver coming from the right hand plug; where the rest of the black with silver wire went I don't know. The grey wire looks like it's teed in to a white with silver wire coming from the right hand plug.