speedometer not working

[fred purple]

So my speedometer only works once ans a while, and I checked all the fuses already. what else should I look for?

[jlevie]

This will either be a problem in the cluster or with the speed signal from the differential. If the car has the 13 button OBC and it also has problems with reporting speed, look to the sensor in the differential. If you don't have the 13 OBC I'd still suspect the sensor first.

[Nairb]

No joke, sometimes my tach doesn't work.. I bang on the dash and it kicks right in. Not sure if you tried that..

Your gears are probably going out, it's most likely a mechanical issue in the cluster itself.. check out www.odometergears.com and pick up some new gears.. will run you about $80 or so depending on the vehicle.. check out one of the MANY DIY guides for this fix, and enjoy your gauge cluster the way it was meant to be enjoyed -- by properly working!

[nando]

the speedometer isn't driven by gears. neither is the tach.. only the odometer.

check the wiring at the diff and also the sensor first. My sensor actually went bad, it cracked somehow. but they're only ~$20.

[Heysüß]

anybody have a shot of what the sensor looks like at the differential?

mine just stopped working as well and the fuse is also ok.

[nando]

just look at the differential, it's the only thing with wires going to it. :p

[MyBeamer]

Use a Sat Nav, like me

[DJB]

The magnetic reed switch in the differential is very reliable. The problem is usually a "baked" connector or worn-through insulation caused by mis-routed wires. The connector shell is easy to replace with a new one. Corroded plug contacts or bad wires requires crimping or soldering a new contact "pigtail" into place -- difficult in the tight quarters.

If you replace the switch, or just pull it to inspect, make certain that the wires are put back correctly. The wires come off of the sensor downward into a "drip loop", are held to the diff by a metal clip, and then go to the body.

[nando]

generally yes they are reliable. But mine definitely broke, there was a hairline crack in it, which I'm sure was my own fault..

[Heysüß]

another noob question, do different diffs use different sensors?

[nando]

no, they're all the same.

[Jean]

no, they're all the same.

Not exactly, for the most part they are the same, but the actual connector is different on the early e30s vs late model. My 84 had different style vs. my 89, shrug.

[nando]

but aside from the possible connector differences (the ix uses a "different" sensor as well), they all use the same type of sensor and the same tooth pattern. Some people are confused and think different differentials with different ratios require a different sensor, which is what I think he was asking.

BMW used the same sensor & wheel in every car until what, the E46 or E90? maybe they're still using it.

[F34R]

anybody have a shot of what the sensor looks like at the differential?

mine just stopped working as well and the fuse is also ok.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=160325711433&crlp=1_263602_263622&ff4=263602_263622&viewitem=&guid=6e7b6a5212a0a026530390e3fff4a44c&rvr_id=126007829692&ua=M*S%3F&itemid=160325711433#ht_4073wt_941

P.S. they are MUCH cheaper else where. This is just a nice close up.

[Jean]

but aside from the possible connector differences (the ix uses a "different" sensor as well), they all use the same type of sensor and the same tooth pattern. Some people are confused and think different differentials with different ratios require a different sensor, which is what I think he was asking.

BMW used the same sensor & wheel in every car until what, the E46 or E90? maybe they're still using it.

Oh yeah, same principal.. I was just talking about the actual connector difference ;)