i got a early 91 d350, the odometer didn't work. i replaced the small gears in the speedo. they were all chewed up. the odometer worked for about 200 miles then quit for about 100 miles then quit again. i pulled the speedo back out and looked it over (i thought possibly one of the old gear teeth got in a spot where it shouldnt have gotten) but everything checked out. i put it back in and it worked for 40 miles then quit for about 45 miles then was taking a few miles then not. it goes on and off. do you think this is a speed sensor or the wiring for the sensor? also when my headlights are pulsating. i dont think this has anything to to do with the odometer but, stranger things have happened.

also the truck is a dually, and has 6 new tires on it. at 60-70 mph it has a bad shake. i was reading in the stickies that you have to properly center them with a tapered lug nut. if they are not centered correctly would that cause a shake at higher speeds or at all speeds? do you think i need to center them or should i look at the front end over for loose or worn out components??

 

If the odometer quits but the speedometer keeps on working, it will be a problem that's internal to the speedo head. If they both quit working at the same time, I would look at the sensor and its circuit.

Those vibrations can come and go at different speeds. I would definitely try centering the wheels first before going into further troubleshooting. Do the simple stuff first, besides, it doesn't cost anything to center the wheels (after you spend a couple bucks on two centering nuts.) While the truck is jacked up to center the wheels, it only takes a minute to give them a shake and feel for looseness for your own peace-of-mind.

 

what do you mean by speedo head? how would i got about checking that out?

 

Speedo head is the part you put the gears in. Mine did the same except changed the gears and still dont work

 

Did you ever get it fixed?

 

Well it may he fixed, I replaced the speed sensor and when I pulled the old one out and moved Tue little pin around and it felt like it was binding up. I checked the new one out and it did not bind up and moved freely also the gasket was bad because it was leaking tranny fluid. I'm not calling it fixed till I put a few more miles on it, because it may he the wiring. After it got it fixed I was going down the road and I lost my marker lights, dash lights, and radio. I put it in park to check the fuses and bam! Lights and radio are working again lol. So we have yet another wiring issue and the odometer might be apart of that. I hope not..

 

Has anyone got wiring diagrams for the odometer motor in the speedo head? and /or diagrams for the entire odometer system [ including pulse generator for the odometer motor and what drives the generator?i.e. magnet on driveshaft? etc etc ?]

 

forgot to enter my truck specs,sorry, NEW to this forum/thread stuff,so don't know how to act! If I'm messing up some body please let me know!! [I'm too old to get it right the FIRST TIME !!! Just ask my KIDS and GRANDKIDS ! ! ] TRUCK:1992 D 350 ,Stock Cummins 2-valve w/Intercooler, Stock Auto-Trans Uglee-Butt-Reeliable ! ! lol. At present odometer reads 99,000 + mi., but odometer inop AFTER replacing damaged gear[s] and manually turning the mechanism as suggested in the " STICKY"[I don't really know what sticky means[besides like"sticky fingers"] SO, if some one has wiring diagrams or can tell me how to hook up w/ a member w/experience or diagrams,please let me know! I hope I' m doin' this right! j.b. Truck is a Club Cab. By the way SPEEDO WORKING JUST FINE THANK YOU ! ! !