I have a 1998 dodge ram 1500 5.9. I have a crank no start issue, so started diagnosing. After research, I replaced crankshaft position sensor, distributor cap, rotor, plugs. Wires, ignition coil, map sensor, iac, tps, battery,asd relay, fuel pump relay, checked all fuses and relays, and new fuel pump. Still crank no start. Tested the connector at the pump and it's testing 12.7 volts. Hardwired a battery to the new pump and it comes on, and fuel comes out of the sending unit(i removed the fuel line to see if fuel comes out, the pump is extremely quiet) i tested old pump similarly in a bucket of water and it comes on also, so pump wasn't issue. I ran a power and ground from the connector to old pump to see what the voltage is when i turn key to on position and it's only reading .73 volts. Fuel gage is working when connected. I'm at a loss. Please help.

 

Need to figger out what's missing. Are you getting fuel to the rail? Are you getting spark?

 

No fuel at rail, I disconnected fuel line from sending unit to test if it was sending fuel at key on or crank, and it does not. The pump works when hard wired to 12v battery. I am getting spark.

 

Blown fuse? Bad relay?

 

Checked all fuses and relays, all tested ok. I'm at a loss

 

Does the fuel pump even try to test at initial key on? If you are getting power to the pump, have you checked the ground? (grab the service manual for your truck from here... wiring diagrams are in section 8W.)

 

I can not get to the new pump to test the connector plugged into the pump to as what volts is getting at key on position, but I did test it on old pump and I'm only getting .76 volts at key on. I assume the ground is good because when I tested the connector, I used the ground and power on the connector and got 12.5 volts. Wouldn't that mean the ground is ok?

 

I am confused.... You state you only get .76 volts at the pump, but, then say you have 12.7 on the connector...... Could you be a bit more clear there?

 

I get 12 volts at connector when connector is unplugged from pump when key is on. When I connect it to pump and test, i only get .76 volts at key on.

 

Then you have high resistance somewhere along the line. Swap the fuel pump relay, and the horn relay. See what happens.