Alfa Romeo Forums banner

1 - 6 of 6 Posts

·
Registered
Joined
·
814 Posts
Discussion Starter #1
& I thought she was running really well...

For some really odd reason my speedo has just stopped working...It was working fine yesterday when I parked it in the garage...When I pulled out of the garage it wasn't...Anyone else experience this phenomenon!

Got any ideas of where to start?

...Bloody gremlins!!!!!!!!!!!!
 

·
Registered
Joined
·
1,430 Posts
When mine went bad, it would work sometimes, not others, mine ended up being the little black box under the back seat.
 

·
Premium Member
Joined
·
13,487 Posts
Me too. I had a used spare box that also turned out to be bad. They seem to have a high failure rate. From memory, there are 3 wires going to the box, in addition to the sensor wires. I think that one should be 12 volts, one ground and the third is the output signal wire to the speedometer. The output should be a square wave signal that varies with speed.

I would inspect the wiring to the sensor and the box and check the voltages. The sensor is an inductor. I think that there is a ground or screen wire + 2 wires to the inductor. The resistance should be fairly low, perhaps around 100 ohms.

Ed Prytherch
 

·
But Mad North-Northwest
Joined
·
10,074 Posts
If you have the Cardisc, there is a very good set of Milano speedo troubleshooting procedures in the TSB section. It'll tell you if it's the head, the amplifier, or the speed sensor.

Before you use them, though, try this: while you're driving, give the top of the dash a good solid thump above the speedo. I thought it was just me this worked for but apparently it is more common than I thought.
 

·
Registered
Joined
·
544 Posts
Don't know if this will help, but....my GTV-6 speedo started hanging up a few weeks ago, and required occasional hard thumbs on top of the dash to unstick it. I finally fixed it permanently this past weekend --- turns out the speedo needle had actually bent over into an arc shape (melted from heat??) and was scraping the dial face. I didn't want to risk breaking the needle by trying to bend it straight, so I just filed off some of the tip of the needle at the end and along the surface facing the dial, so that the needle no longer touches the dial face. Works fine now. Weird, huh?

Dave Spiegelthal

'87 Alfa Milano (75) Gold
'85 Alfa GTV6
Centreville, Virginia USA
 
1 - 6 of 6 Posts
Top