Fuel system blows 20 amp fuse

Fuse 6 (20 Amp) brings power to the fuel pump relay. My instructions say the fuel pump relay is in the fuse box behind right hand side of instrument panel, but an illustration shows it on right side of dash. (The relay is by it self on the fuses side of the fuse box).
Fuse is in same fuse box.

check the amp draw from the window motor may be drawing so many amps that fuel pump /ignition system not getting full 12 volts to work properly

All lights,windows andradio works it will not turnover to start

If the fuse and relay is good, and there is power AT the pump, then the pump is bad. Fuel pump power goes through the oil pressure switch but only after engine is running. So there should be power to the pump for approx 2 seconds when you turn key on. There is a RED wire (prime, it will be a single wire poking out near relay) at the fuel pump relay, if you put 12V on that wire the pump should run, IF the wires and pump is good. The GRAY wire powers the pump.

replace blower motor resistor

bad ground to fuse box

if there is no power to the fuel pump check relays and fuses....UNDERHOOD FUSE & RELAY PANEL IDENTIFICATION Fig. 2: Underhood Fuse & Relay Panel Identification Courtesy of ISUZU MOTOR CO. Fusible Link Identification ? A - 80 Amp (1991-92 3.1L) ? A - 60 Amp Main-1 ? B - 30 Amp Main-2 ? C - 30 Amp (1993-94) ECM (3.2L) ? D - 30 Amp Condenser Fan (A/T Models) Relay Identification ? 1 - Headlight Relay ? 2 - A/C - Heater Relay ? 3 - Starter Relay ? 4 - A/C Compressor Relay ? 5 - Charge Relay ? 6 - Fuel Pump Relay ? 7 - ECM Relay ? 8 - Wiper Relay Fuse & Circuit Breaker Identification ? 1 - 15 Amp (1991) ECM, Fuel Injection System ? 1 - 15 Amp (1992-94 2.6L) ECM, Fuel Injection System ? 1 - 10 Amp (1992-94 3.1 & 3.2L) Heated Oxygen Sensor, Fuel Injection System ? 2 - 20 Amp (1991-92) Fuel Pump ? 2 - 20 Amp (1993-94 2.6L) Fuel Pump ? 2 - 15 Amp (1993-94 3.2L) Fuel Pump ? 3 - 10 Amp (1991) ? 3 - 15 Amp (1992-94) Turn Signal Lights, Hazard Warning Flasher Lights ? 4 - 10 Amp Horn, Door Locks ? 5 - Not Used (1991 3.1L) ? 5 - 10 Amp Charging System, Charge Warning Light WARNING: Always disconnect battery ground cable before servicing "high- current fuses. It is recommended that "high-current" fuses be replaced by a qualified technician. Page 1 of 2 FUSES & CIRCUIT BREAKERS -1994 Isuzu Rodeo LS? 6 - Not Used (1991) (1992-93 2.6L) ? 6 - 10 Amp (1992-94 3.1L & 3.2L) A/T Interlock System ? 6 - 10 Amp (1994 2.6L) Heated Oxygen Sensor, Fuel Injection System ? 7 - 20 Amp Heater/Air Conditioning Blower Controls ? 8 - 10 Amp Air Conditioner Compressor Controls ? 9 - 10 Amp Right Headlight ? 10 - 10 Amp Left Headlight © 2008 Mitchell Repair Information Co., LLC.

Underhood fuse block swap out relay #7 thats the ECM relay.
Ground Circuits Using a DVOM, touch negative voltmeter lead to a good ground. Touch positive voltmeter lead to each ground terminal. With vehicle running, voltmeter should indicate less than one volt. If reading is greater than one volt, check for open, corrosion and loose connection on ground lead. See ECM GROUND LOCATION table for ECM ground location.
Page 1 of 1 SYSTEM/COMPONENT TESTS - 2.6L EFI -1994 Isuzu Rodeo

cannot send diagram,technical problem,but its the 20 amp fuses one labeled fuel pump,other injectors/fuel

You have a problem in the fuel pump relay circuit for sure then. I'm betting the relay, but it could be that dropping resistor.

i just had this problem with my 93 dakota. my truck had a fuse in the same fuse block as the relays. i had to end up bypassing the relay with an inline fuse holder that i put a 20 amp fuse in i later found out that these trucks had a problem with the auto shutdown system that i was unable to figure out.