I changed the starter on my 1995 tahoe 4x4 and when i go to crank it thr big ignation b fuse under hood keeps blowing the 50 amp but the wires are not touching on starter?

Try disconnecting the starter solenoid control lead and see if it still blows the fuse when no engine crank while switch in start position.

Try disconnecting the alternator and see if symptoms change.

You might also try using a 12V test lamp (or better, a headlamp) in place of the fuse. It may not crank but it allows you to low power circuits without blowing fuses. Observe lamp brightness as you go from run to start. Brightness is relative to current flow.

Comment for further assistance.

Try jumping the starter with the key on. If it doesn't blow. Check the start wire for chafing and grounding out. You can pull the starter relay, Try to start it, see if it blows,yes, it is between the fuse panel and fuel pump. no. Put it in and pull the fuel pump relay. Start it. If it blows, then it is some where between the fuse panel and starter. If you have one of those intelligent fuse panels, it could be that also. You can have the codes read for it. But it takes a scanner, not a code reader.

FUSES BLOW BECAUSE THE COMPONET THAT IT PROTECTS IS EITHER PULLING TOO MANY AMPS OR YOU HAVE A SHORT. LOOK FOR BARE OR BURNED WIRING

50amp only clue and you dont have the book, the FSM.
nor access to alldata.com?
if you did youd, not be asking right?
my guess is that fuse is in the mains box under hood..
and is a real fuse and not a circuit breaker found elsewhere....????
old car, and can be anything this old.
sounds like fuse #33 in the main box blew. and feeds the white wire main.
USA car? ABS opted? A/C opted. sure.
top cause, shorted alternator, so take off that big wire from alternator
and see if fuse blows now. (do so with battery neg lug removed
the remove alt big wire and tape it all up, so it can touch metal.
then put back battery Neg lug, and last the fuse.

the whtte feed goes vast places and runs whole sections of
the cab fuse boxes and power windows.

if the Alt is good.
then you must start dropping all white wire loads.
if it still blows, the harness is shorted.
I personally just uses a temporary circuit breaker in place of the
50 amp to find the short and an ampclamp DC ammeter.
fast.
login to alldata.com and follow the big white wire.

You have a short in that wiring, most likely related to your starting motor. Pull the starter relay (in the underhood fuse box) and try a new fuse to see if that is the case. If so you will need to have the motor checked. If not, there are a variety of systems that use this feed via the ignition switch and each will have to be checked (including the switch). If you need a wiring diagram, try Alldatadiy.com.

go to the front axle and take the actaushwaiter out and gert a new one

Check both under the hood driver side to thr rear of the batterie. And in the dash.

you need a new starter I just went through this problem had my starter changed and have not blown any fuses in days....oh and by the way getting to the starter was not and easy task.

sorry this is not going to make you happy but its a wire shorting out to the negative side of the battery it could be anywhere under the hood, look for any wire that look chaffed, hope this helps regards John

You have a large wire that powers the ECM, it has rubbed through and is grounding out and blowing the fuse, locate the power source for the fuse under the hood, then look for damaged wiring, check places were the wires touches the body, it will not be easy, it takes time and a keen eye.