Speedo Problem Need Help!

gb0 · 05-21-2004, 07:22 PM

I just finished changing out the gear to fix my odometer, the speedo was working prior. When I start up the car the speedo shoots up to 150 and stays there. Any idea what would cause this? It is a VDO gauge from 1983 911sc. Any suggestions would be appreciated.

Thanks,

Gerard

RSBob · RSBob's Garage

Take it apart again and double check everything

MY83SC · 05-21-2004, 09:47 PM

And this must be why 911's look fast, even when still!

fintstone · fintstone's Garage

I suspect you have swapped the sensor wire with another on the back of the gauge.

gb0 · 05-22-2004, 04:02 AM

When I took it apart I made a connection diagram. Kind of hard to mess up that way but just in case. There are ony three wires to connect: power to + ground to - and sensor wire goes beside the ground terminal, I dont't remember the gauge marking off hand. This does leave one connector on the guage with nothing attached to it. The gauge is electronic. Any more suggestions? Does the bentley repair manual cover guage troubleshooting?

/Gerard

fintstone · fintstone's Garage

From an earlier thread:

Quote:

Looking at the back of the speedo, the group of multiple terminals at the right side of the gauge are, from left to right:

two brown wires andone brown with red stripe
one brown wire with red stripe
one red/white wire and one brown/black wire
one red/black wire and one red/blue wire

The bulb socket at the bottom gets the bulb with the black/blue wire.

The bulb socket at the top on the right gets a bulb with a black/blue wire.

The bulb socket at the top on the left gets a bulb with a white/green wire.

At least that's how it is on an '83 SC.

gb0 · 06-06-2004, 01:08 PM

Well the the saga continues. I found a trace on the board that was lifted and broken so I ran a jumper. It also looks like I have a blown resistor and this is where I need some help. I need the value of the resistor that is closest to the 12V lead wire on the speedo pcb. The colors are gold / something / something / orange. Does anyone know what this is supposed to be?

Thanks,

/Gerard

Lorenfb · 06-06-2004, 01:24 PM

Send to Pelican. They have suppliers that can repair it and calibrate it.
Why risk damaging it further?