Bouncing Odometer - Finally Died

[wicks]

Well I got along there for some time with the dancing/bouncing/intermittent reading on the odometer, but I haven't seen a life sign in about two weeks now. Last time I saw a number it still seemed to be reading right.

What have people done about this - just replaced the whole speedo? From who? VDO alternative? Hmm.

What's clear is that the number is still "in there (where?)" somewhere, and perhaps one could just replace the LED screen. Hmm?

Any ideas, input greatly appreciated. :hmm

[rover4x4]

VDO seems to be the best option as it has been discussed at lentgh on this forum. I think George (RDS) had the Genuine speedo a while back it may be worth a try to contact him.........

[chrisvonc]

Last month he had one for a '97 at a good price. I just had to replace mine for a '94 for the exact same symptoms.

[m.michaels]

Mine did the same thing . . .

I put out a reply on Wanted - and was contacted by someone who had a Stock Sppedo lying around (I assume from taking theirs out). The thing had caulk all over it (which is good because my hardtop gets LOTS of water inside) - and through several dousings there are no problems or blinking . . . .

[BarryO]

Mine did the same thing. I took the speedo apart. The liquid crystal display connects to the PC board via a "flex circuit", i.e., conductors on a flat piece of plastic. It goes to a special connector on the PC board; the flex circuit is inserted in the connector and then a locking ring is pushed down to lock it in place. I re-seated the flex circuit and all is OK now.

Obviously with this many complaints, there is a design problem here. I strongly caution anyone considering doing this, however, that these are very delicate components (the flex circuit and connector) and easily damaged. Unless one has alot of experience handling and fixing PC board electronic equipment, it's best to take out the speedo and take to a speedo repair shop and let them deal with it.

[wicks]

Ahhhhhh. Barry - that's what I was hoping to hear. I shall open mine up presently. I used to overclock my own Macs back in the day, so I should be OK. ;)

Did you notice the odometer was clealry continuing to track in the chip or whatever and all seemed normal once the display was back on-line?

Follow-up Post:

How did you get the bezel off?

Follow-up Post:

Done, odometer FIXED, perfect, original count back on screen. Barry is the MAN. THanks!

[BarryO]

Yup, the bezel removal is the trickiest part. The "jeweler's screwdriver" method is what I used as well.

'glad I could be of assistance. ;)

[wicks]

Died again. What do I do now. Dancing constantly.

[mrmuddy]

When I had a similar problem on a J**p it was the speed sensor. Makes sense when you think of an electronic componant down in all the crap under the vehicle.
John

[BarryO]

Mine died, too.

When I get it back from the body shop, I'll need to try to fix it again.

I noticed the contacts at the very end of the flexible connector were pretty worn. I'll try either painting some conductive paint on them (the stuff they use to fix PC boards), or I'll just trim a little bit off the end, so that it sits down lower in the connector, and the connector makes contact with parts of the flex that aren't worn.

You'd think that, with VDO's reputation, we wouldn't have these problems.

[ripp2002]

Can you upgrade a 94 to a 97 speedo?

Larry

[artm]

I noticed the contacts at the very end of the flexible connector were pretty worn. I'll try either painting some conductive paint on them (the stuff they use to fix PC boards), or I'll just trim a little bit off the end, so that it sits down lower in the connector, and the connector makes contact with parts of the flex that aren't worn.


Forget the trimming. paint the contacts, refit the connector and put some silicone on the mating point so there's no movement.

[wicks]

Barry - did you ever try this with the trimming or paint - or what Arthur said?

[BarryO]

Not yet, but I'm doing it this weekend. I'll let you know how it goes.

[shawnpalmer]

I did just like the pics but cleaned the connection and it brought mine back to life. It is not that difficult.

[artm]

A run of silicone keeping the connection tight is really worth it. This trick is commonly used in portable computer systems (no, not laptops) to keep IDE/SCSI and similar ribbon cables from becoming disconnected during rough carriage.

And it's totally undoable of course.

[Eric_S]

How long does this take to fix?

[Matt Taylor]

Could somebody walk the more retarded of us through what Wicks was doing in that series of pictures?

Specifically:

1) How'd he get the bezel off

2) What electrical connection was he repairing

Thanks. I'd like to take a shot at this soon.

[BarryO]

Matt,

I promise I'll take pictures this weekend.

If I remember correctly, the bezel just kinda pries off. You need to get it off to take the speedo apart.

The connection that's being repaired is the one from the odometer display itself, to the main circuit board of the speedo. It's a "flex circuit"; i.e., the connectio to the display isn't a cable, it's a pice of mylar with copper traces on it. It attaches to a connector on the circuit board; when that connection goes bad, the odometer display gets flakey. The last time I fixed this, I just took the flex circuit out of the connector (you need to unlatch a locking mechanism first), and re-seated it. That fixed it for awhile, but it's not a long-term fix.

This seems to be an extremely common problem with the speedos in the '97's.

[Matt Taylor]

Thanks, Barry. That clears it up a bunch.

Looking forward to the pictures.

[Cyborg]

The odometer in the speedo of my 97 has not worked for over 2 years.It flickered and jumped all crazy for a year before that. I took mine apart and tried the ribbon cable fix. No luck. I took it to a local speedo shop.... the guy cannibalized a new VDO for the LCD display and installed into mine. I picked it up and hooked it up. It didnt work. The speedo part worked fine like before but not the odometer.

I walked right back in and told the guy.... he hooked his test syrtem up to it....he alligator clipped 12V to connection #2 and gnd to #3 and said that the odomter worked perfect. I decided to take the unit home and see what I could do. He claimed that the speedo part and the odometer display were powered from these same connections. But if the speedo worked when plugged into the vehicle why wouldnt the the odometer??

HMmmm?

I decided to take all of the the trucks wiring out of the equation so as a test I jumpered those connections from the back of the speedo directly to the battery terminals. The odometer worked perfectly.

Now I knew it had to do with the truck wiring somehow. I sprayed some electrical contact cleaner onto the vehicles plug and then tried it again..BINGO!! It worked....so I put a litttle dielectric grease onto the connections and put it all together.

OK so now it is fixed but I am wondering if mine had been merely the connections on the back of the speedo all along and if the speedo guy who didnt check my original speedo on his test rig did unnecessary part replacements?

Anyway guys, moral of the story....if you are having the same problem be sure to clean and check the connections on the back of the speedo before you assume it is internal.

[BarryO]

Larry,

Thanks alot fror the post!!!!

I didn't post a follow-up to my last post because I was becoming suspicious of the very same thing, but did not have enough evidence. My last "fix" with the flex circuit wasn't reliable, either. However, it seemed just the act of unplugging an re-plugging the back connector helped. Your story would tend to confirm that.

Here's my latest hypothosis: the odometer, being an LCD, uses very little current. However, the plating on the connector is either solder, tin, or silver. These are OK for most automotive uses, as the current flowing through the connection inhibits oxidation.

But if you only have microamps of current, that may not be enough. Usually, gold-plated contacts are used in such a circumstance. Such is not the case here.

[Cyborg]

Went out to my truck this AM with the intent to wrap up the loose ends of the instrument cluster. I was looking forward to admiring the functional odometer that I had just fixed. DAMN!! It isnt working AGAIN!! It merely set there overnight and somehow died.

I tried all of the cleaning the connector on the back and then jumpering the two connection on the back directly to the battery...nothing. Speedo working fine as usual...odometer dead.

Took it back to the speedo shop. I will get it back in 3 days...we will try again.

AARRRGGGgggghhh! This is frustrating!