Thanks dieselzen and rancherman84 ...
I'll re-check the under carriage tommorrow morning when I get home.
Tommorrow I'll also lift the fuse box up to have a look at the wires coming from that fuse and try and follow them.

 

Turbo..
I was reading this post feeling sorry for ya man! I think you can go to "autozone.com", type in the truck, year,etc. and look up any parts. They also have electrical schmatics on line, I'm pretty sure. I've got the factory services for my old work horse (from ebay) and they've been a great help. Those little pains sure make you learn more about your truck, don't they! Stay with it.

 

Thanks ditch witch
I went to Autozone.com and registered and will do a search in a few minutes to see what I can find.

 

Well I finally got a chance to do the search and came up the wiring schematic for my truck there.
I worked 12 hrs and didn't get home till 10am so I just got up and it's dark!!
So I'll try again in the morning.

 

hey guys...
I picked up some liquid tape,20A,30A fuses...
I'm going to tackle this in the morning,starting at the back of the truck and checking for broken wires or dirty connections.
Hope you guys are here!

 

Well I've had it!!
I give in...
Had the truck about a year and half now, never blown a fuse and now all of sudden turn the key to accessory and it keeps blowing this fuse taking out the TACH and OVERDRIVE!!!
I've checked everything that has been posted but can't find what's causing it.
If I was a little more mechanical/electrical inclined but I'm not.
I'm going to have to bring it in to a shop.

 

Sounds like you're at the point of tracing every wire out though it seems it would have to be a large wire which is grounding as small ones would most likely just burn open if they were taking enough amperage to blow a 20 amp fuse. And it also seems to me that if it isn't a large wire which can handle at least 20 amps, then some device in the elec. system which can draw 20 amps would be the culprit. I wonder if maybe the RPM sensor itself has developed a short condition inside it? Have you had the alternator/reg. checked yet? Hard to come up with answers not being there to poke and prod. R.A.

 

Thanks dieselzen
I really appreciate all the help you've given me with this.
I'll be dropping the truck off tommorrow and will be looked at Monday.
I'll post back after to let you know what it was.
Thanks everyone.

 

Well I got the truck back today...here's what was wrong:

The Fuel Heater shorted...that was what was blowing the fuse.
Also the RPM Sensor was finnished.

Total bill:
Fuel Heater Assembly.......$233.82
RPM Sensor.......................$84.64
Fuel Filter Adapter.............$20.00
Labor........2hrs..................$143.00
Total...................................$564.42

The weather here has been crazy,last night the temp dropped to -42C!!!!
Cold!!!

Thanks for everyones help!!

 

Turbo Tuff,
Glad your ride is fixed and you've got it back. Hopefully, your troubles are behind you now. Wish the bill could have been less. Brrrr, that's a whole lot colder than where I'm at. R.A.