1990 Accord EX speedometer/odometer not working

:banghead: Yes, I can hear the groans... I've searched the forum and found lots of info about bad VSS's and flashing "S" lights, but it doesn't apply here.

Subject is a $600 '90 Accord EX, 4 cyl., 5 speed, "reads" 170K miles. Purchased a couple of weeks ago for resale, overall runs great & is in good condition and only needs a couple of things.

But I am perplexed by the speedometer/odometer not working.
I gather this is a common enough problem, and I've checked the shop manual, on here, and other websites and still am at a loss.
The Check Engine light is not on now, though it did have a code for a bad coolant temp sensor that was fixed and cleared with a new part. No other codes are thrown.

Radio wiring is hacked & patched, but a factory radio plugs in and works perfectly. Taillight wiring is also hacked for clear taillights, but brake and taillights all work. I am unsure if the cruise control works.
VSS Wiring looks OK, and all fuses including the #1 10A fuse are good.

In spite of no CEL I replaced the VSS but it did not fix it.
I found a tip on leaving VSS plugged in, removing from trans., chucking the drive pin in a drill and spinning the pin with the ign. key On to check VSS, and had no response from Speedometer. That site suggested if the drill test fails, the "mechanical part" of the VSS may be bad, or the speedo. head could be at fault. Gauge cluster is now apart, and I assume the speedo. head is the coiled copper wires behind the speedo. face but I am not sure, and can't find any info on the speedometer head.

I am leaning towards a bad cluster circuit board, because in addition to the speedo./odo. not working, the Safety Monitor has intermittent ghost lights for Doors Ajar even when they're not, "Brake Lamp" light won't go off but could be due to the taillight wiring hack job, and the tachometer works, but is sticky when the engine is revved. Fuel and temp gauges seem to work fine. I'm pretty sure the dash has been removed before, but everything else electrical works OK. The only other weird thing I've noticed is that when either the climate control Recirc or Fresh air buttons are pushed, the assembly behind the glove box hums like it can't shift, but it doesn't hum when both buttons are pushed at once and neither is selected.

Question is: would anyone recommend attempting to replace just the speedometer parts to try to fix, or should I just replace the entire cluster? Or is there another possibility I am overlooking??
It may seem minor, but I would really like to fix this to help with reselling the car.
Thanks in advance!

I would try to replace a circuit board. But it is quite hard to find one.

Keep us posted.

Sam

Thanks Somick...
after a LOT more research last night of old threads the circuit board is what I was leaning towards. Was going to reply then but the phone died in the middle.

Would a good salvage circuit board from any 4th gen. plug in and work?
I know a used part may/may not have issues but the '90-'93's are pretty common here in the pull your own parts yard. Have not looked for a 'new' part, I assume that is what you mean are hard to find?
Didn't make it to the junkyard today but intend to snag a couple used units out there tomorrow. Will post back with progress.

As an aside, and also thanks to his forum, I may know what the hum is from the recirc/fresh air selector. Another thread mentioned it could be a bad vacuum diaphragm in the assembly behind the glove box. I don't know what that is, but I'm going to find out & grab one of those as well, hopefully from one that the dash is already apart.

Thanks!

Couple of years ago I searched Ebay, but could not find anything decent.

Keep us posted.

Sam.

http://i1286.photobucket.com/albums/a613/lovesstickshifts/WP_20130606_002_zpsd6490b93.jpg
http://i1286.photobucket.com/albums/a613/lovesstickshifts/8f1b29dc-96f7-4b29-b218-7ff0942acd4d_zpsa679a7ea.jpg

Ok, got my replacement, got it home & plugged in the whole cluster to see if it worked, and even less stuff on the replacement worked...no oil light or engine light came on at all, and none of the gauges worked.

After taking the cover off both clusters to look at the circuit boards, I see they're both burned looking in the same place, and the replacement has a little more crud in a different spot. D'oh! Is this what happens to cause the speedometer failure?
The top one is from a '91 LX (automatic), the bottom one is what came out of the '90 EX (5 speed).
If I return the replacement and get another (after making sure the circuit board doesn't look like these) can anyone tell me if all circuit boards are interchangeable, or does it have to be a '90 EX 5 speed? Most of the 4th gens there were auto's including the only 1990, but there were 1 or 2 sticks, one was a '91 I think, plus there are loads other junkyards I can prowl.
I also read somewhere an early 90's Civic cluster circuit board would work, is that true?
The automatics are obviously slightly different but I don't know if the differences ("S" light as opposed to no "S" light, etc.) matter when used with the 5 speed display?

Any thoughts?

From what I can see in the pictures, the circuit board do not look the same. They are apparently not interchangeable.

Sam

FIXED!!

Unfortunately I cannot say 1 simple thing did the trick as a helpful tip for others. But, in combination, these repairs ultimately fixed the failed speedometer. Tach operates normally, fuel gauge seems to fully function, and the safety monitor does not have ghost "door ajar" lights now.

* THOROUGHLY rechecked all of the connections under the hood. The trans. has been out, presumably for a clutch by the look/feel of things, and some connectors were loose or broken.
* Electrician friend cleaned the "burned" areas on the original cluster board. After, the paths that were completely shot were exposed. A thin, insulated copper wire was soldered to each solder point on the bad path to restore the connection.
* The VSS was replaced. Since it did not initially fix anything, it probably wasn't the issue, but I am going to leave it alone.
The oil and seat belt light don't work now, but I believe a loose connection in the warning light wiring is at fault, probably from being put in/taken out repeatedly. Will fix that before selling.

Thanks for the help with this, and hopefully it will help someone else down the road.

Thanks for the update. I am glad it worked well.

Sam