23chris

Hi, I have a 95 F150xlt with the 5.0 L 302 engine. For several months I had a flashing airbag light that I ignored. A few weeks ago my #18 fuse blew. I replaced it and the speedometer and odometer stopped working. The o.d. cancel light started flashing, and the transmission started shifting hard. I replaced the vss and the speedometer with a unit that had a working psom. The #18 fuse still blows each time I turn the key to the "on" position. Does the airbag system run through the #18 fuse, and if so can I disable the airbag to cure the blown fuse? Any help would be greatly appreciated. .

Chris_1

iTrader: (1)

What year truck did you get the psom from ?

23chris

To be honest not sure. Bought it on ebay. Was under the impression that any years between 92-96 would work. I do know that the odometer briefly comes on before the fuse blows.

Chris_1

iTrader: (1)

The PSOM is fairly year specific. I understand that 92 & 93 will interchange, and 94 and 95 will interchange and 96 will work in 96.

23chris

Wow I didn't realize that. Everything I had read said they were interchangeable. I'll contact the seller and see if he knows what year the speedometer is from. I just requested one with the mileage the closest to the mileage that was on the original.

Chris_1

iTrader: (1)

I'm just going by what others have said. Apparently there are some wiring changes in the cluster. I've been researching, but can't find much of anything definitive on the psom - seems to differ depending on who wrote the opinion.
Currently trying to figure if we can use a 96 gas cluster in a 96 diesel. Apparently we have to swap over the gas gauge and tach because diesel ones are different, but I'm still trying to find out the difference in psom's or if there is one.
I just know that quite a few people have said that the different years won't match up, but they don't say exactly why, so I'm still looking for something definite.

Chris_1

iTrader: (1)

So far I'm finding things about the circuits being different in the different year clusters. Supposedly no difference in the PSOM's other than the early ones are not as good because they couldn't compensate well for a poor VSS signal and the later ones (95 - 96) had been improved.
I wonder if anyone else knows of any other differences.
As for your #18 fuse, there are a number of things on that circuit. I read a post of someone unplugging them all and plugging things back in till the fuse popped.
If the problem is in your airbag, I'd recommend finding the short and fixing it. Other than not having an airbag when you need one, I'd worry about the airbag somehow going off when you don't expect it to.
I'm just not a big fan of just unplugging things. You never know what effect that will have somewhere else is my reasoning there.

23chris

I contacted the seller of the psom I bought. Understanding that he's in the business of selling parts, he told me that every psom he lists is tested on a '96. He did offer an exchange if I wanted. But you are correct in saying there could be an issue with the airbag system. I disconnected the airbag diagnostic monitor and no more blowing fuses. I could see no obvious issues with the adm itself, so I'm going to check the sensors. I'm also going to put my original speedometer back in to see if there was ever a problem with it in the first place.

23chris

I did read in several sites that a psom from a gas or diesel are interchangable, and that they will work in F150, 250, or 350. I will try to find the references and pass them onto you if it would help your situation. There's also a YouTube video showing how you can rebuild a psom.

Chris_1

iTrader: (1)

If you can find them that'd be great. I'm trying to find as much info on these clusters and speedometers as I can to try and get a definite answer as to what works with what and what can and cannot be interchanged.