Working really good for 95,000 miles, had to replace an alternator, a bearing, replaced shocks rotors calipers. No big deal, its getting old. This Crank fuse going out is starting to wear me thin. Had a diagnostics check, oh yeah crank fuse. ok..replaced. Week later bamn there it goes again.. Well, I replaced it with a 10 fuse, and ok for a couple days. Darn thing leaves me stranded again yesterday with another blown fuse..well, ok I have 4 more. All blown before the engine even turns. Is this a short? and if it is where?

 

What is a 'crank' fuse? Where is this fuse located?

 

Hi. The crank fuse is in the Engine compartment fuse block located under the TBC fuse. It is to the right of the Fog LP Fuse. Its the Clutch Switch, and NSBU Switch. I also am wondering why the TBC fuse is just able to pull out without any force, like it is sitting in there?

 

Ah, okay, gotcha. What problem is the truck giving you - not starting, or cutting off while running? My first thought would be that perhaps a grounding strap for the tranny might be loose and shorting the NSBU if the truck won't start.

 

not starting, no crank. and I had the fuse replaced, ran for about a week..blew again. not cutting off while running. I mean my horn everything works great, have good voltage, just this darn fuse keeps blowing, even after the dealership checked it. I figure a short somewhere, but just not sure where..grounding strap. where is that located?

 

We're starting to get out of my area,but here is a diagram of the connections on the A/T.



[IMG]local://upfiles/4800/7D183717584944B681F433E651CFDAEA.gif[/IMG]




(1)
C104

(2)
Park/Neutral Position and Backup Lamp Switch ConnectorC2

(3)
Park/Neutral Position and Backup Lamp Switch ConnectorC1

(4)
Oxygen Sensor Bank1, Sensor1

Hopefully one of the members with more electrical or transmission info will get in on this thread.

 

The Crank fuse services the Transfer Case Shift Control Module (purple wire - cavity E11 w/o auto4wd or cavity D16 w/ auto4wd) and Park/Neutral Position and Backup Lamp Switch (purple wire - cavity E on connector 1 - 7 pin). The TCCM is located behind the passenger side kick panel in front of the passenger door.

This is causing a no crank condition due to the fact that the PNP switch is not getting power. Without power, the PCM cannot verify that the transmission is in park or neutral, hence the no crank.

Now, you can remove fuse and the connectors from the TCCM and PNP switch and test for continuity to ground on either of the purple wires. Next would be to reconnect the TCCM and repeat the continuity to ground check. Repeat with the PNP connector connected and the TCCM disconnected. If you find that there is no continuity to ground with any of these checks, then I suspect it is an internal fault in either of these components that grounds out this line during operation. If I had to guess, I would suspect the TCCM.

 

I missed your post, I was out of town for 3 weeks! hate to say swartlkk, that it has already been tried..and it still blows in about a week an a half...

 

Have you tried a larger fuse? Not a permanent fix, but you have to assess what is drawing the additional current. It is possible that there is a broken wire causing a higher draw..? Just throwing out ideas. Short of replacing the wiring harnesses... Don't know what else to tell you. You could put an ammeter across the fuse location and monitor the draw to see how high it actually goes...