Odometer not working on 91 940. Took 5-6 attempts to get the trip to reset. I'm thinking gear problem as I have replaced 2 of them on 240s now. But thought I would ask here since I don't know anything about the 940s odometers. Is there any common failure points in the 940's (specifically 1991) odometer? Speedometer works fantastic by the way. Seems that often the 940s speedo/odometer fail together.

Thanks everyone!

 

It's the speedo diodes that fail on this car, and you need a new or rebuild one. For DIY there's a great write up in the brickboard.com (700-900) FAQs/
in this case, fail to reset, it may be a question of the mechanicals (gears) damage. I'd crack it open and look...

 

my 92 745 with 200K miles, the pushbutton to reset the trip is very stiff, I'm pretty sure thats sign that it will break before long, and probably bust the odometer with it.

our 87 240 odometer stopped at 250k miles about 15 years ago. I figure its got 400K on it now.

I know you used to be able to get these rebuilt for about $100 at Palo Alto Speedometer (in the SF Bay Area) and I'm sure many similar places across the country, but I dont even know of PA Speedo is still in business.

 

The 740/940 odometer is different from the 240, but not any more reliable. Unfortunately, fixing it is not just a gear replacement like in the 240; there's a mini electric motor that goes bad. When the speedo itself fails, it's usually due to a couple of capacitors that leak whatever is in them all over a couple of connections. Rick Borth at Overseas Speedometer in Austin TX showed me exactly what happens. The bad news is that it is such a PITA to fix these things right that most shops, his included, don't mess with them any more. I'm in the process of trying to get mine repaired and will let everybody kinow if/when I get some positive results.

 

appreciate the info Joseph, just wondering if it applies to my situation since my speedo is working great. Just the odometer is gone, I hope this means that the odometer can be fixed more easily than what you describe.

 

Joseph/TX, Any word on how to get the odometer fixed? I've got mine torn apart in the living room right now. i have no idea what's wrong as my visual inspection tells me nothing. Where exactly are the diodes on this thing? Once again, it's ONLY the odometer that is not working. Everything else (speedo/warning lights/fuel gauge/temp gauge) is working great. Everything that is, except cruise control (don't know if that has anything to do with the odometer, but thought I would throw that in there.)

thanks in advance for any ideas!

 

well, if the motor is bad, there's really nothing you can do but replace it.

 

Ugh. I'll have to head to the parts yard and see what I can round up.

 

Just wondering if I can drop a 740 speedometer in a 940???

I'm pretty sure the cluster won't fit.

 

Actually a '91 740 speedo may work in the '91 940, the cluster is the same, as is the rest of the car... Also, probably '92 740...

 

Yes, I've swapped a 91 740 cluster into a 92 940...all worked well...

 

yeah, 91/92 740s are really 940's, in about every respect except the trunk of the sedan, and stitching on the seats..