Just brought home my new (too me) 1993 B250 conversion. Wanted a full size van for 20 years and I finally got it! 150,00 miles and it definatley needs work. But driving it is a awesome. First things first, the speedo doesn't work. Not really anyway, doesn't budge until i get to about 40 MPH (guessing) and then it will start moving up to 10-15. I'm guessing the problem would be the speed gauge at the end of the transmission but I'm wondering if this is the best guess. Is there a way to test it? Yes, I'm a relative noob at working on cars but i know i"m gonna have to do most of the work on this myself. Thanks for any advice, and anyone with recommendations for what to do first or next I'd be more than happy to hear. So much to check and replace I'm having a hard time deciding where to start.

 

The vehicle speed sensor is the likely culprit. My VSS is inline on my speedo cable and it works by a spinning magnet opening and closing a reed switch inside. The ECM sends the VSS 5 volts, and 5 volts is pulsed back to the ECM which then determines speed.

I just had to replace my VSS as the contacts of the reed switch got a little too friendly to each other and would not separate.

There is probably another sensor on the differential, I do not know if this is for the ABS or another VSS.

You should get a factory service manual. They are miles better than a haynes or chilton.

Goto e bay motors
Type in 1993 van service manual

Congrats on the Van ownership, and good luck.

 

Thanks Landy, got the Chilton on ebay (you were right) and I think it's the speed sensor on the tranny. Got the part at advance and I'm ready to install, problem is there is so much caked in road on the undercarriage I'm having a hard time spotting the old one. There are a couple of things plugged in where the manual places this and I don't want to wrip something out that doesn't need ripping.

 

That sensor on the differential is just for the ABS (RWAL). For the speedo, only the one on the tranny needs to be changed.