geronimo wrote:
> The speedometer had stopped working, although the odometer was still
> running. Replaced the instrument cluster with a used one. The
> speedometer then worked for the first test drive, but on the next,
> the speedo needle started becoming erratic, and then died altogether.
> THis time, the odometer is not working, either. I spliced test
> pigtails into the pos. and negative signal wires from the
> sender---right at the speedo connector. At 60 mph (more or less)
> with a digital multimeter reading rms AC volts, the signal is 2.0
> volts. Not much of a signal...but there may be an amplifier. I am
> sure it is a pulse train, and so the indicated voltage is probably not
> accurate. I don't have a scope to read the p-p voltage, to see if it
> is still normal. I would like to know for sure that the signal
> amplitude is still high enough to drive the speedometer OK before
> telling the vendor that the speedo died the same day installed. It is
> maybe not likely, but I could have had some problem with the sender
> circuit (and still do) combined with a failed speedometer MPH
> needle. (Boy...the hits just keep a'comin!)
>
> I'd just as soon forget the OEM speedo altogether and install an
> aftermarket one.....but they don't seem to be common and are
> expensive. I found one speedo repair shop that will repair Volvo
> speedos, but its very expensive. But then "pot luck" with a much
> cheaper used instrument cluster sure isn't working out.
>
> Regards, geronimo


The sender is a variable reluctance pickup, it consists of a coil of
wire with a magnet and it senses pips on the differential assembly.
Works exactly like the pickup on an electric guitar, the output is a low
voltage AC sine wave of varying frequency and amplitude depending on speed.

I've never seen an aftermarket speedo for a Volvo but I'd imagine it
would look like an ugly hack. Good used speedometers are plentiful and
cheap, and any TV repair shop should be able to fix the solder joints on
one to get it going.

James Sweet wrote:

> I've never seen an aftermarket speedo for a Volvo but I'd imagine it
> would look like an ugly hack. Good used speedometers are plentiful and
> cheap, and any TV repair shop should be able to fix the solder joints on
> one to get it going.

I've seen cars fitted with a $5 bikecomputer glued to the fascia.
Provided you can read it at night, it served to get the car pass the
vehicle check

--
---
Marten Gerritsen

INFOapestaartjeM-GINEERINGpuntNL
www.m-gineering.nl

Here they don't care whether your speedo works or not....but I care
about not getting tickets. Does a bike speedo really work? Goes up to
75 or so? Seems like the max would be much lower. And how would sender
work? It matters not at all how rigged up the car is, as its next
stop will be the junkyard, I expect.




On Wed, 28 Mar 2007 08:38:39 +0200, M-gineering
<ikmotgeenspam@m-gineering.nl> wrote:

>James Sweet wrote:
>
>> I've never seen an aftermarket speedo for a Volvo but I'd imagine it
>> would look like an ugly hack. Good used speedometers are plentiful and
>> cheap, and any TV repair shop should be able to fix the solder joints on
>> one to get it going.
>
>I've seen cars fitted with a $5 bikecomputer glued to the fascia.
>Provided you can read it at night, it served to get the car pass the
>vehicle check