Speed sensor.

[zak]

92 4.0 4X4 ax15

 

I'm on my 4th speed sensor, and this one is starting to go out again. Sometimes is works fine, sometimes is doesn't work at all and reads 0 even if I'm going. 45+ and then will randomly jump up and work until I shut the truck off. Now yesterday it was working fine and then starting jumping all over the place, both up and down, then returned to normal.

 

Has anyone else had to replace theirs nearly every two years? This time around it hasn't happened yet but in the past if it wasn't working and the speedometer was reading 0 even while I was moving it would shut off if the RPMs dropped too suddenly while I wasn't in gear or didn't down shift very quickly.

 

Do I have another problem that keeps causing these speed sensors to fail?

[Rockfrog]

Sure you don't have a wiring issue? Trace the wires coming off the VSS, or possibly it's a cluster issue.

 

 

Sent from my SGH-I337M using Tapatalk

[zak]

Sure you don't have a wiring issue? Trace the wires coming off the VSS, or possibly it's a cluster issue.

That's what I'm starting to think, but I would think that even with a new sensor it would still act all crazy if there was a bad wire. Every time I've replaced the sensor it's been fine for a year or two and then starts to go out again.

 

I'll try pulling the cluster and make sure all the connections are good.

[HOrnbrod]

I agree it's probably wiring as these sensors rarely fail. Make sure the cable connectors are plugged in securely and clean on the cluster and that the speedo mounting screws are tight. Check the cluster's foil printed circuit for cracks and tears. I have a few of these foils if your's can't be repaired.

[zak]

Thanks everyone, I'll report back once I get a chance to check the cluster and wiring.

[HOrnbrod]

Check THIS out. Similar problem, same year...........

[schardein]

I noticed on the way to work one morning that my speedo wasn't working.  Everything else seemed to be ok.  I looked down 10 minutes later and it was now working.  Over the course of several months I would occasionally notice it wasn't working first thing in the morning.

 

I've since switched instrument clusters twice.  And since then I've never noticed it not working.  Perhaps in my case it was the screws on the instrument cluster or the wiring connection.  

[HOrnbrod]

92 4.0 4X4 ax15

 

I'm on my 4th speed sensor, and this one is starting to go out again. Sometimes is works fine, sometimes is doesn't work at all and reads 0 even if I'm going. 45+ and then will randomly jump up and work until I shut the truck off. Now yesterday it was working fine and then starting jumping all over the place, both up and down, then returned to normal.

 

Has anyone else had to replace theirs nearly every two years? This time around it hasn't happened yet but in the past if it wasn't working and the speedometer was reading 0 even while I was moving it would shut off if the RPMs dropped too suddenly while I wasn't in gear or didn't down shift very quickly.

 

Do I have another problem that keeps causing these speed sensors to fail?

 

I'm curious - does your 92 use a 3-wire or 2-wire VSS?

[zak]

I haven't had a chance to take a look at anything yet, and it's also been working the last few days. If I get a chance after work today I'll take a look to see if it's 2 or 3 wire.

[FrankTheDog]

Two wire vss on the 92's. Mine does the same exact thing.

The tell tale is that the truck works fine for a year or two then the speedo starts jumping around and it stalls if you're not paying attention.

It did the same with the old sensor.

I know if I put in a new sensor it'll stop for a while.

[HOrnbrod]

Looked it up Frank, shows up in the parts book as 91-92 being the same, then 93 went to the 3-wire. When you guys change them out, are you using the Mopar VSS (p/n 5252438) or aftermarket? My speedo hasn't acted up yet, but I'd like to have a spare handy.

 

[FrankTheDog]

91-92 two wire. Standard motor products speed sensor. Cheap parts.

Is it possible to get a mopar speed sensor?

[HOrnbrod]

Yep, about $50-$60, p/n 5252438. Mopar calls it a SENSOR, Distance, on Trans. The p/n crosses to Duralast, Standard, Airtex, etc. p/n's and all the aftermarkets call it a speed sensor. It's just a reed switch in a case, so I wouldn't mind an aftermarket unit in this case.

[FrankTheDog]

It may last longer in your climate. Last two winters it saw a lot of salty winter weather. That probably hastened it's demise.

[zak]

Sorry for the last response. I was out of town. But yeah as a few of the other guys have already said, it’s the two wire.

 

I’ve always just bought what I could afford at the time, but I don’t think I’ve ever went to the dealer for the mopar replacement, first time I went to the local autopart store and I think I paid around 60-80 and then after that I started using rockauto when I knew it was going bad again. Although I had to return one from rockauto, don’t remember which brand i bought but it seemed to be accurate to about 25mph and then after that the needle just crawled to about 35 even if I was going 70.

 

I hasn’t been acting up the last two days so I haven’t taken the dash apart yet, I’ll get around to that later in the week, guess I’ll order a spare sensor in the meantime and ride this one out until it dies.