Volvo 240 1990 sedan. I found the broken gear and replaced it with new. In the process the motor cover was separated from the circuit board. I carefully put it back together but it still doesn't work. Any suggestions?

 

Please give a reply. I'm stuck. At the suggestion of another forum I removed everything again to see if there were any errant pieces of the old gear and found a couple. Now its all clean again and reinstalled for the tenth time! Still not working

 

is just the odometer not working, or is the speedo dead too? was the speedo working before you took it apart?

the gear is purely an odometer thing, the speedometer works even with a broken gear. if the speedo isnt working, it can be a number of things, theres a chip on the circuit board that dies, there's capacitors on the circuit board that die, and the wire from the speed sensor in the rear axle can break.

 

Never a problem with the speedo. Only the odo doesn't work

 

hmm, then other than the usual 'examine circuits closely for swollen or leaking capacitors' and maybe resoldering the solder joints in case any are 'cold' and failed with time, I'm pretty much out of ideas. I read something somewhere about a chip in the speedo module that fails, I dunno if it can fail such that only the odo dies

hey, did you read this procedure?
Volvo 240 Odometer Repair

the bit about tiny broken pieces getting stuck definitely could be your problem. also the 'drive an hour+ and it started working again mysteriously', who knows?

ah, and here's the electronic approach, including the '2115' chip
Electronic Speedometer Notes

 

I doubt that it is the 2115 chip since your speedometer still works. Usually if you fry this chip, both the speedometer and odometer doesn't work.

If you are electronically inclined, you can bench test your speedometer/odometer. Check out this link:

Electronic Speedometer Notes

I did this with mine using an old AC adapter. It put out a 60hz 12v signal that gave me about 21mph. Good for a go/no go type of test.

 

dear act1292... Okay... "use jumper in place of flex circuit fuse" I don't get this part. I have a 12v ac adaptor that i use to check my bulbs. I don't want to FRY my spedo.

-------------------------do you guys understand that the metal housing that is glued to the circuit board that covers the gears separated from the board breaking the glue. There are three pins protruding from the circuit board that were either attached to the metal "motor" cover by solder which I don't see, or were simply touching the right parts of the motor to make it spin. I may take it out again and take a picture of what I'm talking about.

 

hey... will the car work, run, lights etc if I just take out the speedo and put the cluster back in?

 

there is a signal from the speedo to the ECU on some cars. i'm not 100% sure what it does. the speedometer and ABS controler are both connected to the rear sensor, I'm not 100% sure if the ABS will work right with the speedo disconnected

 

Okay... mine is not equipped with ABS so I'm probably okay... thanks Pierce!!

 

What is the take people...should I just buy another odo/speedo? here's what I found. I opened it up again and with a magnifying glass could see that the three pins that go through the circuit board into the step motor had that thin copper wire on them which means that I separated the pins/board from the motor. I carefully removed the pins from the board and slid them back into the step motor thin wire first and then resoldered the pins to the board. This may or may not fix the problem. Second thing though was that I found a broken gear in the fifteen tooth also and when I touched it, the whole gear crumpled like candle wax in my hand. If I replace the gear, the step motor might still not work and then I've also purchased the gear on top of the first gear. or $30 that I could put towards a working odo. I could replace the step motor and circuit board if I could find one.... any help?

 

Tell you the truth, I would go grab a cluster from the JY. I pulled a cluster and it cost me $35. However, chances are when pulling one from the JY it may have a bad odometer gear as well since this is a common problem. When searching the junkyard, look at the trip odometer. If it shows 000 then the gear is bad. Not showing 000 doesn't guarantee a good one though. Also, try to get a cluster from an '89 or '90. A '91 model might work if the car it comes off of does not have ABS. I believe that '92+ models all have the ABS speedo regardless of whether the car has abs or not. ABS speedo won't give you the correct speed readings since the tone ring in the differential that provides the signal is different.

You can't run your cluster without the speedometer circuit board without some adapation. All the power for the cluster comes in from one of the wires on the three wire connector to the speedometer. If you disassemble the speedo circuit board from the rest of the cluster, there is a bare u-shaped wire that goes from the speedo circuit board to the cluster circuit board. This provides the power to the remainder of the cluster. Also, there is a small flexible circuit board that is attached by two screws. This is actually a fuse for the main circuit board and also needs to be in place.

 

if you were creative, you could rig up a small 12V battery (maybe 8 AA batteries?) and a source of a low frequency sine wave (could be anything from around 60Hz (around 20MPH) up to like 300Hz (~ 100MPH) at about 0.25-1V peak to peak. you might be able to get this out of a guitar tuner that has a headphone output, with that output turned up quite loud (by headphone standards). you'd hook up the 12V to + and - on the speedo, and the audio between - and the "O" or whatever its called input signal that normally comes from the sensor in the rear axle. this would let you spin a speedo and odometer at the JY...

I got my inspiration for this idea from Electronic Speedometer Notes

guitar low E is 82Hz, the G string is 249Hz...

 

Gday, Posting for anyone reading this in 2021. This was not my thread but I had a similar situation and hope my info can help others.

I definitely had a broken gear (small gear on 89 240) when I opened mine up. Thought it would be a simple replacement, reassemble and away it goes.
Unfortunately not. I had 5 tear downs, with broken bulbs and lots of frustration before I got a fix. I was also wondering if I had broken the motor or some other wiring during the replacement but with nothing obvious and visibly broken, and more importantly without the skills / tools on hand to test it, I decided to persevere with realigning the gears and once more and hope it worked.

Another post reassured me that perseverance can work, as it took them 5 times to get it working, without any OBVIOUS problems in the previous cog installation / replacement (i.e extra broken gears or other parts blocking the cogs / missing parts etc.,). So with all that in mind, here are my ideas:

1. After you replace the gears and screw the ODO motor back onto the odometer housing, use a pin or very thin metal object to poke throught the plastic motor housing to turn the brown motor disc, anti clockwise. You should see the ODO numbers counting up. It took me a while to figure this out as it is very fiddly but once you get the hang of it, it is very easy to show the motor spinning the gears and the odometer is counting up.

2. While spinning this brown motor disc, it should spin freely. If not, then the screws holding the motor down are too tight. On my last (successful) installation, I loosened the screws to a point that feels unnatural. Certainly much looser than I have left a screw on anything in my life. Not even gently tight. So loose that the actually motor housing and the electronic board which protrudes through the back of the instrument cluster could wobble slightly (about 3-4mm in either direction). I would say this was about half a turn of the screws back from gentle tight with a screwdriver. In this position I noticed that brown motor disc moved much more freely than before. I believe that the special washers under the screws which hold the motor in place, are probably designed to hold screws in, even when slightly loose.

3. Clean the electrical contacts (mainly the three pins that go into the instrument cluster + the three metal stripes on the board which is connected to the cable in the dash. To do this I used isopropyl alcohol and contact cleaner and some hard but gentle rubbing (in tricky spots I was use a pin or screwdriver to apply pressure to a cloth and rub. Also give the three rectangular pin connector housings a VERY gentle crimp with some pliers after cleaning. You can see one side of pin house protrudes into the rectangle to make contact with the pin. This one is easy to bend slightly further to ensure there is a good contact.

4. In the car, before reinstalling the cluster, turn the key to the on position and test the odometer connector pin with a multimeter (its the one with three wires going into a plastic plug). simply put the multimeter on volts, and put the red to red, and the black to the black (and the blue) and you should read 12 volts. This will tell you that you have no problems elsewhere in the car.

5. Install and test!




WHERE TO BUY
The link below is the where I bought my odometer gear. It works fine. I think its located in Australia so probs no good for far flung places.
https://www.ebay.com.au/itm/132487620155

BULBS
Jaycar (Australia) has instrument cluster bulbs on hand behind the counter for a very good price. So you can take yours in and double check you are buying the right ones before ordering 50 off ebay.

 

You can buy a rebuilt Odometer. Not just the gears but the circuits for $375.

The https://www.swedishcarparts.com/part...repair-service