1990 S4 Speedo not working
#16
Find connection T19 (a 14 pin flat connector) at the central electric panel. Pin 10 and 11 wires should be brown/red trace. You can take an ohm meter and set it so it beeps when you touch the leads together, put one on 10 and one on 11 and then go spin the wheel. If you are getting the on/off pulse there then your speed sensor is good and the problem most likely resides in your instrument cluster. If you don't get the pulse then either the speed sensor is bad or the wiring harness has a break in it. The sensor should be the left front tire.
Been a while since I've had to trouble shoot one of the later cars so I may have missed something there.
Been a while since I've had to trouble shoot one of the later cars so I may have missed something there.
#17
Thread Starter
Okay I will give that a try.
Your comment about the instrument cluster has me wondering as I can see that it has been out before and a couple of the tabs for the four main connectors are damaged. Someone has connected another wire to one a brown wire as well. The volt meter would cut in and out with a tap to the pod. The pod itself was not installed properly. I recently found all the external pod fasteners in a bag of extras that came with the car. I put it back correctly when I did the ignition switch and cleaned all the connections.
Should note that the speedo stopped working before I restored the pod correctly! Has me wondering though as the cluster looks like it took some abuse previously.
Your comment about the instrument cluster has me wondering as I can see that it has been out before and a couple of the tabs for the four main connectors are damaged. Someone has connected another wire to one a brown wire as well. The volt meter would cut in and out with a tap to the pod. The pod itself was not installed properly. I recently found all the external pod fasteners in a bag of extras that came with the car. I put it back correctly when I did the ignition switch and cleaned all the connections.
Should note that the speedo stopped working before I restored the pod correctly! Has me wondering though as the cluster looks like it took some abuse previously.
#18
Rennlist Member
Ole.......your car is perhaps different as it originally was in Japan.............easy check though; take the front lh wheel off and see if theres 2 sensors ABS and speedo?
I had the GTS LH hub apart so will post pics
I had the GTS LH hub apart so will post pics
#19
Thread Starter
#20
Archive Gatekeeper
Rennlist Member
Rennlist Member
One thing I don't understand is how there could be a megnetic pickup held onto the diff cover if there's no wire attached to it- did it get ripped out by road debris or something? The pickup is hardwired to the, uh, wire.
Here are two shots of the left front spindle from above and below on a '91, for reference/wire routing. You can see the tip of the ABS sensor peeking out from under the dust shield:
And the medial side of the (right front) spindle, showing the ground wire for the ABS/brake pad/RDK sensor harness.
Here are two shots of the left front spindle from above and below on a '91, for reference/wire routing. You can see the tip of the ABS sensor peeking out from under the dust shield:
And the medial side of the (right front) spindle, showing the ground wire for the ABS/brake pad/RDK sensor harness.
#21
Thread Starter
Okay. Took off the left front and confirmed it is the same as both sets of pictures. Looks like everything is as it should be and in very good shape visually. I have quite a few suggestions to work through and then I'll report back what I find.
I took a few pictures of the diff cover that I'll post later.(have to renew my membership first) Definitely no wire and there never was. Also has a heat shield over the cover.
Thanks for helping!
I took a few pictures of the diff cover that I'll post later.(have to renew my membership first) Definitely no wire and there never was. Also has a heat shield over the cover.
Thanks for helping!
#23
Thread Starter
#24
Archive Gatekeeper
Rennlist Member
Rennlist Member
Whoa-whoa-whoa-
The vertical upainted bracket in Malcolm's picture is the RDK sensor bracket- The speedometer signal is derived from the front ABS sensor (or sensors, there's a cryptic sentence in the 1992 Service Info booklet about when the speedometer signal moved from the front ABS sensor(s) to the left rear...)
The vertical upainted bracket in Malcolm's picture is the RDK sensor bracket- The speedometer signal is derived from the front ABS sensor (or sensors, there's a cryptic sentence in the 1992 Service Info booklet about when the speedometer signal moved from the front ABS sensor(s) to the left rear...)
#25
The ABS sensor is the speed sensor guys.
#26
If ya got the wheel off, unplug the ABS/Speed sensor and take your ohm meter to it. Spin the hub, you should have a pulse. If no pulse then it's the sensor, if ya do then you need to work further up the line. Check all the barrel connectors etc.
I'm guessing that since there is an issue at the POD that the issue is there. One thing people miss is when you open the cluster it has to fit just right, sometimes the pins on the back of the cluster bend and do not get in the proper connector and then things don't work. I'd say pull that thing and take a real close look.
I'm guessing that since there is an issue at the POD that the issue is there. One thing people miss is when you open the cluster it has to fit just right, sometimes the pins on the back of the cluster bend and do not get in the proper connector and then things don't work. I'd say pull that thing and take a real close look.
#27
Drifting
In addition to what Sean said. When you put the 4 plugs in the back of the cluster, they do take quite a bit of effort and force to seat properly. When they seat properly the lever locks automatically.
#28
They do require a bit of force to snap in place. Make sure the levers are .......well.......level.
#30
Thread Starter
[QUOTE=SeanR;11466591]If ya got the wheel off, unplug the ABS/Speed sensor and take your ohm meter to it. Spin the hub, you should have a pulse. If no pulse then it's the sensor, if ya do then you need to work further up the line. Check all the barrel connectors etc.
Is there a secret to unplugging? I don't want to damage the connectors!
Is there a secret to unplugging? I don't want to damage the connectors!