99 Stroker with OD light flashing

[99 Red Stroker]

This is new to me. The wife was driving the truck this evening and the speedometer quit working and the overdrive light started flashing. Could this be a speed sensor on the rearend or am I way offffff? I have a 99 350 4+4 dually. Nice truck that we haven't had just about a week or two. It has a 7.3 with an automatic and 145,000 miles. Hope someone can help. I thought I had seen this posted before and searched and didn't come up with anything.Thank you to all !!!!!!!
99 Red Stroker

[mschn99]

sounds like the rear diff speed sensor is probably bad as you thought.....im not normally one for throwing parts at things, but i would in this situation...put the sensor in and disconnect the battery cables for a half hour...

[99 Red Stroker]

Thank--s Marc,
You guy's are great. The thing I forgot to put in is that the speedometer and the light stopped flashing after about 3 or 4 miles. I kinda figured it will come back if I don't take care of the problem. Things like that don't seem to happen until someone else is driving HA!!!!! The thing is that my wife is real good at keeping an eye on things which is great. Am I on the right track as it will come back? I haven't been under it to look at the wire connection. I will get a new sensor and inspect the wiring at that time. Sometimes I scare myself. I know I live in southern Ia. and I'm kinda close to the MO. line HA!!!!
Thank you once again.
99 Red Stroker

[mschn99]

ive commonly seen speed sensor have intermittant problems, and yes, it will come back if this is the case. Obviously look at the wiring while your there, but it sounds like a pretty cut and dry speed sensor failure to me..

[99 Red Stroker]

I went to the parts store this afternoon and picked up a speed sensor. When I looked at the rearend the only thing on it was what looked like a ABS sensor on the top front. I even called the parts store to see if the 98 and 99 were the same as I thought there may have been a mid year change. The part that I have looks like it should drive on a gear out of the transfer case or the tail of the trans. I looked both over real good and no luck with finding anything. I need to get a service manual it would sure help. Any ideas would make me smile or I could be over looking something. thank you
99 Red Stroker

[mschn99]

the rear diff speed sensor is in the rear diff just where you discribed....sounds like they gave you a wrong part to me!!!

[99 Red Stroker]

I'll do another part look see. It didn't seem right to me (who am I to question the parts man ) HA!!! I'll get back when I find out and get the right part in.
Thank'''''''s
99 Red Stroker

[99 Red Stroker]

I took back my part this morning and drove 120 miles to get the right one. Our local Ford dealer didn't have it in stock and I thought it would give the truck a good run anyway. The more I drive it the better I like it. The fuel prices kinda suck as the gas prices did with our other one HA!!! I haven't checked the fuel mileage yet. I filled it when I got back so I could give it a true check. It does have 3.73s and hope to get 17 to 18. What I drove today the sensor didn't act up. I'll have to drive it a while to see if the new one done the trick. Thank's for the good info. As always from what I've read on here you've been there and done that HA!!!!
99 Red Stroker

[mschn99]

glad to hear you got it fixed buddy!!!