the 30 amp starter fuse (#113) on my 2002 excursion keeps blowing.
put in a new starter and it continues to blow fuse.
tried to look for possible shorts in line with no luck.

 

Manual or Automatic Transmission?
The power leaves your battery and goes thru a junction block then to two fusible links. It then goes to a central junction box with a 50 amp fuse. It leaves this box and goes to the ignition switch and then to the start pin of the switch. It then leaves the ignition and goes thru a central junction box again and thru a 15 amp fuse. Leaves here and goes to the Clutch Pedal Position Switch(CPPS) and then to the starter relay on the solenoid side and then to ground.
The main power that goes thru your 30 amp fuse goes to the main contacts of your Starter relay and then to the starter Bendix and eventually to ground.
For the 30 amp fuse to be blowing the only likely culprit after your Starter replacement is the Starter relay. (Not the starter solenoid) The other thing that could be it could be a loose positive battery cable, Corrosion build up at battery terminal or in your battery leads or a loose lead at positive on your starter/bendix. I would check every lead Tight.
You can also clean up the wires and ensure they are tight but the most likely culprit is the Starter Relay.

 

unfortunatly the starter relay is good
Not sure what 2 do next

 

the truck is automatic
have started unpluging things to see if their is a short somewhere
no luck
hope I dont have to bring it to the dealer

 

checked battery cable
cleaned and reaseated all connections
fuse still blows

 

Inspect the Positive cable from the fusible link(at the connection box closest to the battery) and the fuse and then from the fuse past the starter relay all the way to the starter. This is not just a cursory look. This is a hand over hand inspection of the cable. Look for anything that is burnt or cracked or visually messed up. You need really good lighting for this.
Also remove both of your ground cables between your frame that go to your battery NEGATIVE terminal.
The current still has to flow thru these negative cables to the batteries. Ensure to do all of them. The drawing shows two grounds on one battery and one ground on the other. Wire brush the cables and clean up the place on the frame it connects to.
The only other explanation is the bendix in the starter but you said it was new.

 

Do you have a starter solenoid under your hood mounted somewhere on the passenger side under the hood. On the f250's they are on the left side. Similar to a glow plug solenoid but will be on the left side of the engine mounted above the wheel well. There will be large red cables coming to it from the battery and then to the starter. ????

 

No starter solenoid mounted to fender on 2002. 2001 was last year for it. However, there is a connection there that should be checked for damage/corrosion. It is behind on the battery on the inside of the rt front fender. It is basically where the solenoid would be was there one. There is a one wire weather pack connector there with an orange (i think) wire in it. It is probably fine but does not hurt to check it.

 

working on cable inspection and cleaning
can not seem to find fuse links
will look again

 

any chance it could be the ignition switch

 

Fuse 113 is the small wire that engages the starter. It leaves the fuse and goes to relay c2163 (top right of fuse box) and then goes thru the connector I mentioned earlier to the starter. it is a yellow wire with a LB stripe from the relay to the starter relay I was wrong about the color. So, it is either a bad relay, a bad wire, or a bad connection to the starter. There is always the possibility of an issue with the fuse box as well.

The fusible link for that circuit is before the fuse that you have blowing so I would consider that a non-issue as it feeds that part of the fuse box.

If u have an ohm meter, measure the resistance from the cold side of the fuse to the #30 blade of the relay. IF that is good, measure the resistance from the 87 blade of relay to the small wire at the starter. That will require some alligator clips and a jumper wire to complete. Disconnect the small wire from the starter before checking. If that is good, it is in the starter.

 

measured the resistance from the 87 blade to the wire as you recomended.
I get 3.8 ohmes

 

2.8 ohms from the 30 on the relay to the bottom post of where the 30 amp goes. 0 ohms from the top post

 

Its a little higher that it should be. The almost 4 ohms is what is really bothering me but I know the jumper wire adds a little to it. However, that is still only 3 amps in the circuit. When u take your leads of your meter and just touch them together what is that reading. That could be some of it

Take your relay out and ground 85 and put 12 v to 86. Measure the resistance between 87 and 30. Do it once and then do it again in say 10 mins with it plugged up and see how if it changes.

 

It will not be the ignition. The ignition goes thru a 15 amp fuse to the solenoid side of the starter relay. The thirty amp fused circuit goes through the CONTACTS on the starter relay that the 15 amp circuit/ignition circuit fires.
If you do not know how a relay works then I will describe for you. A relay allows for a smaller wire and smaller fused circuit to operate a solenoid(coil of wire with a metal core that moves). This metal core that moves operates a Very large set of contacts(similar to a light switch) to allow a much larger current to flow through. It is all located in a small plastic assembly or hard plastic with the studs or pins to connect to the system.
I hope this helps. Can you take the small positive lead going to the bendix off and look to see if it is touching the transmission case or engine case? If you have verified the wires and you have some pretty low resistance readings there then I would be giving the starter another look even though it is brand new. You want low readings on the wires. When the relay is not picked up it will be low. I do not know how many ohms the solenoid side is but the solenoid side of the relay is part of the 15 amp circuit from the ignition. New things are sometimes no good. I know it sucks to pull the starter because I had to do mine last year.