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Another speedo/od question!

2K views 18 replies 9 participants last post by  justinfonder 
#1 ·
I have a '93 D350 and it will randomly drop the speedometer, odometer, and overdrive. It will pick back up and work eventually and then quit again. Totally random. I just replaced the speed sensor with no luck. And the drive gear looked good on the sensor housing. Was wondering what past experiences y'all had with with this problem? :S:
 
#9 ·
i have a similar issue in my 93 w250 getrag. it's happened to me 3 or 4 times now in the past 4 months. each time it's a bump that makes it go out and a bump that makes it come back.
 
#10 ·
Yup same thing here...still have the same problem somewhere...but have checked and cleaned every ground wire and connectors I could find on mine...most of mine cleared up. But every once in awhile my airbag light will ding off n on and the engine will cut out. But not as often as it used to.:banghead:
 
#13 ·
ya i have a 92 w250 and my speedo and odometer stopped working when i had my auto and i did a getrag swap and still isn't working someone said just to get a gps that does speed an keeps mileage. a good garmin cost $50-$100 on amazon.
 
#14 ·
So.. I'm wondering if it's not my harness. Use to be able to move the CPS around and it would come back. Now you can't do that. It is also related with wait to start light now as well. If wait to start light does not come on you will not have speedo or OD. The battery seems to not be charging as much or at all if the speedo and od is down. Harness? ECM?
 
#16 ·
Pretty much everything your describing as not working is dependent on a good clean signal from the CPS. You need to verify that the CPS is in good working condition, and that the air gap is set to .049-.051.

Also check all the connections and wiring from/for the CPS right on back to the firewall and PCM. There are a number of connections that the signal has to go through in the harness. If there is corrosion, or broken or frayed wire at any point along the way, the signal may be degraded enough that the PCM will not recognize that the motor is running.

It's going to take a little bit of effort to find the problem.
 
#19 · (Edited)
my speedo just started jumping all over the place a couple days ago. it will level out once up to speed but sometimes it will just start jumping all over when driving and even when sitting at a stop light idling. this happens maybe every other time i drive it. any ideas? was thinking it was just that sensor in the back of the t-case? anyone have a part number for that thing?

i just read something that makes perfect sense. i was driving in a really bad rainstorm when it first started happening. i guess water gets into the connector/vehicle speed sensor and causes the jumping. going to take it apart, clean it good, and seal everything up, especially where the wires go into the connector.

i'd still like to replace the VSS if anyone knows a part number?

rockauto has it listed as PN - SC105 or SC105T , can anyone verify this is correct? looks like it comes with the connector at about 1/3 the price of advance auto
 
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