94 860 odometer kaput... Fixable?

[Doug Warner]

The good Tire shop gave me a free rebalance because I had driven
only 150 miles in the last 3 months.

The bad My odometer quit working 150 miles after I had the
wheels balanced the first time..

Went to run the Function Test (A7, press button 3 times), but I found
the wire already plugged into A7. I must have forgotten to unplug it
when I changed the oil. I figured that this might be the cause and
unplugged it.

Next day, odo still NG. Tonight: Ran the Function Test.. All the
needles point where they're supposed to, but the odometer doesn't even
twitch. (Speedometer works, so it's getting the the speed input
signal.

Leaving A7 plugged in shouldn't have done it, since it just goes
directly to an IO pin on the combined instrument microprocessor.

I'm hoping it's just a cracked solder joint. Has anyone
disassembled the combined instrument enough to see how the odometer
motor / solenoid is wired up? Is it driven directly by the main
board, or by electronics within the speedo assembly itself?

Now to find out how to remove the thing from the dash.


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[Mike F]

The good Tire shop gave me a free rebalance because I had driven
only 150 miles in the last 3 months.

The bad My odometer quit working 150 miles after I had the
wheels balanced the first time..

Went to run the Function Test (A7, press button 3 times), but I found
the wire already plugged into A7. I must have forgotten to unplug it
when I changed the oil. I figured that this might be the cause and
unplugged it.

Next day, odo still NG. Tonight: Ran the Function Test.. All the
needles point where they're supposed to, but the odometer doesn't even
twitch. (Speedometer works, so it's getting the the speed input
signal.

Leaving A7 plugged in shouldn't have done it, since it just goes
directly to an IO pin on the combined instrument microprocessor.

I'm hoping it's just a cracked solder joint. Has anyone
disassembled the combined instrument enough to see how the odometer
motor / solenoid is wired up? Is it driven directly by the main
board, or by electronics within the speedo assembly itself?

Now to find out how to remove the thing from the dash.

To reply, please remove one letter from each side of "@"
Spammers are VERMIN. Please kill them all.

There's a gear that cracks, so it doesn't grip the shaft that the
odometer digits are on tightly enough to turn it. I had this problem on
my '76 240, and "damaged" the shaft with vice-grips to enable the gear
to grip the shaft. Or head on over to http://www.odometergears.com/ and
buy yourself a new one.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

[Doug Warner]

There's a gear that cracks, so it doesn't grip the shaft that the
odometer digits are on tightly enough to turn it. I had this problem on
my '76 240, and "damaged" the shaft with vice-grips to enable the gear
to grip the shaft. Or head on over to http://www.odometergears.com/ and
buy yourself a new one.

I just took it apart with the help of:
http://seawinds.ws/volvo/instrument_cluster.htm
(Very difficult to remove the cluster out the way it's shown here.
It looks like I'll have to remove the passenger airbag moduleto free
the right end of the dash cover so I can reinstall the cluster without
forcing it.

Mine has a missing tooth:
http://webpages.charter.net/dwarner2/ODOgear.jpg
This is the one that's turned by the gear on the motor shaft. I'm
guessing it's the 15 tooth one odometergears.com is selling for
$25.00, since I can't see any other 15 tooth gears in the unit.
http://www.odometergears.com/subpages/volvo.html


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[James Sweet]

There's a gear that cracks, so it doesn't grip the shaft that the
odometer digits are on tightly enough to turn it. I had this problem on
my '76 240, and "damaged" the shaft with vice-grips to enable the gear
to grip the shaft. Or head on over to http://www.odometergears.com/ and
buy yourself a new one.

His car is a '94 though, the speedo's (and odometers) went electronic in '86
on the 240's and earlier than that on other models.

 

[Mike F]

His car is a '94 though, the speedo's (and odometers) went electronic in '86
on the 240's and earlier than that on other models.

Yes, but as you can see from his second reply, electronic 850 speedos
have problems with the gears, just as 240s with mechanical speedos do.

--
Mike F.
Thornhill (near Toronto), Ont.

NOTE: new address!!
Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

[Doug Warner]

Yes, but as you can see from his second reply, electronic 850 speedos
have problems with the gears, just as 240s with mechanical speedos do.

Yep.. And, if anyone wants to see some photos:

First, after a big struggle getting the cluster out while bending the
right half of the dash up, I removed the glovebox, a few more screws,
the right speaker, and the airbag calbe and bolts. then lifted the
whole dash out. A 2.2 ohm resistor in the airbag connector keeps the
controller from posting an ignitor fault:
http://webpages.charter.net/dwarner2/Topless.jpg

Back of the cluster. To get the front window section off, remove the
screws indicated, as well as the nut around the boost gauge stem.
http://webpages.charter.net/dwarner2/PanelBack.jpg

Front view. The dial plate is clear acrylic, about 1/4" thick, Just
pry it offm working around the edge. It unplugs from the board in
back
http://webpages.charter.net/dwarner2/PanelFront.jpg

Open view: The pins on the instrument actuators plug into the board.
Reassembly involves pusing the panel back on, taking care to avoid
fingerprints on the flat black surface.
http://webpages.charter.net/dwarner2/PanelSplit.jpg

The odometer is, located by a couple of pins in holes. A 2-wire
connector links it's motor to the board. Just lift out and unplug.

I removed the motor from the odometer's right side and found this:
http://webpages.charter.net/dwarner2/ODOgear.jpg

The 15-tooth one from Odometergears.com is the replacement. On order.

And, while I'm posting photos.. if you like macadamia nuts, don't buy
this:
http://webpages.charter.net/dwarner2/NUTS!.jpg
(It's what I found in the can.)


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