308 speedo

The error you are quoting sounds a bit like a km/hr to mph conversion factor - is that at all possible ? When you are travelling at 50 mph it shows 30 mph which is 50 km/hr for example

 

I bet Palo Alto could repair it for you if necessary.

http://www.paspeedo.com/

 

Well, you can bet that PA Speedo could fix it, but before you lay down your hard-earned cash, let me tell you about my experience. All dates took place in 1999:


Called for estimate. Told them *exactly* what my problem was. They told me $178. Was told it would take about a week. Sent speedo. This was late March (the 26th to be exact).

April 13 - No speedo. Called PAS. Was told price would be $225. I said go ahead (mistake). Hartmut told me it would ship out 4/14 or 15.

April 26- Still no speedo. Called PAS. Was told that the shipping paperwork "dropped through the cracks" and would ship that day.

May 5 - Still no speedo. Called PAS. Was told that it shipped 4/26 and was given tracking number. Ok, checked UPS website - at least it was in town.

May 6 - Rec'd speedo. Opened package. Speedo was broken. "9", halfway between 3 and 4, 6, halfway between 5 and 6, and a gear showed through the odometer window (and the odo was what they were supposed to be *FIXING*!!!)

May 7 - Called PAS. Told Hartmut of the problem. Said he would send UPS call tag to pick it up.

May 13 - No UPS call tag rec'd. Called Hartmut. It fell through the cracks (again).

May 18 - Still no UPS call tag. Called Hartmut. Checking with UPS.

May 21 - UPS finally picks up speedo.

Today (June 6) - still no speedo.

As I see it, Palo Alto Speedometer screwed up no fewer than five times on this one job:

1. They underestimated the cost by 28%.
2. They failed to repair and return the unit in a timely fashion.
3. They failed to repair the unit correctly (remember, it fell apart in shipping).
4. They failed to retrieve the unit in a timely fashion.
5. They failed to fix their screw-up and return the unit in a timely fashion.
6. They offered no compensation for their repeated screw-ups. Nor would they agree to any when I asked for some.

At this point in time, PAS is high on my list of companies to avoid like the plague. They will have to refund my money in full before I'd even consider recommending them to anyone else (even then, I'd be hard pressed to do so). Can anyone else recommend a better company for guage repair??? Just my experience. YMMV.



Ok, so that was in 1999, but first impressions are lasting, and that was my first with them (and last). The speedo was finally returned and it did work. But they did not get the odometer milage set correctly as I had requested. Fortunately, this was not a big issue at the time of sale of the car. All I can say is a hearty "GOOD LUCK!!" (you'll probably need it!).

 

wow.

Okay, I take back my suggestion.

 

Difaz, the speedo senders ARE NOT interchangeable. The early one mounts vertically on top of the R/H side cover for the transaxle. It has a female nut and screws on. The later sender mounts upward at an angle underneath the R/H side cover. It is essentially a brass male threaded plug.
I would bet you have a speedo head designed for the late sender and using it with the early unit would cause incorrect/erratic readings. If you remove the speedo head from the dash, there should be a postage stamp-sized sticker with Ferrari p/n, Veglia p/n, "GEN" or sender number and "REVS/MILE" info on it. If you provide me this info, I may be able to help you sort this out. E-mail it to [email protected].

 

How many distributors does your car have?

 

Jimmie - great logic. Could have been a car for the european market or the wrong replacement speedo has been fitted prior to Difaz buying the car.
(looking at the recent reports in the UK press, Tony Blair would never have figured this one out...)

 

Hi
Firstly check that your speedo is not in KM instead of MPH (as Greyboxer indicated.) E.g. 100 KMH is 60 MPH.

I can speak from experience with what Brian Keegan said about the units NOT being interchangeable.

My original 308GT4 speedo failed as a result of an altenator blowup. I had it repaired locally in Toronto. A year later it failed again. I then bought a used speedometer on eBay. It had a Dino faceplate but inside it was for the newer sensor. This one exhibited your symptom. So for a year I drove 'by feel' and by gear/RPM approximations.

Rather than spending a lot of money again, I built a prototype replacement circuit using an LM2917. It works but needs some refinement and the addition of a PIC microcontroller to deal with the odometer drive. I wil eventually finish the design and build a few circuits. Just not too sure when.

The circuitry of the 2 speedo models is vastly different. On the older models there is a trimmer with which you can adjust the speedometer reading. On the new one there is no adjustment.

The senders are also not mechanically interchangeable.

If you need photos of the internals of both styles, just let me know by a PM.

Gerrit
http://dino308gt4.com

 

Hi
glad you at least know what the situation is. Here are a photo of 1970's style board and the later style. On the early one there is a trimmer, on the other there are no adjustable components.
Image Unavailable, Please Login
Image Unavailable, Please Login

 

If you can also post the part number of the IC then we can tell from that what possible adjustments can be done by changing components.
Certainly with the LH one this is possible. The RH one I could not find any information on the chip they used.

Gerrit

 

Now that is fascinating. It seems that Veglia worked along the same lines as Ferrari, use whatever happens to be nearby during assembly They obviously had a stack of the old style on the shelf and wanted to use them up so added the daughter board.

The top board is a frequency divider (ITT SAA1004 is a Freq div chip). I am guessing that if you took that board out of the circuit that the lower board can do its original job again.

Both chips of course are long out of production.

 

Another possible solution (and useful to others who want to recalibrate due to tire size changes) is http://www.terf.com/SpeedChangerPage.htm .