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Hello I have a 2004 ml350 that the fuel pump will not turn on I just replaced my water pump and put it back together went to start it and all it does is crank there was not fuel pump noise so I checked fuse and relay both are good so I replaced the pump and still nothing while so I tried to jump the relay and I the pump still won't turn on
Excuse me as I gave you the wrong instructions. With the key in the ign., place your testing device (DVOM or test light) on one of the fuse contacts, then have someone turn the key to the on position , NOT START POSITION; while you quicklly test both contacts for 12v on fuse 13.
Do you understand?
Last edited by Maj. Dundee; 11-15-2020 at 04:28 AM.
Excuse me as I gave you the wrong instructions. With the key in the ign., place your testing device (DVOM or test light) on one of the fuse contacts, then have someone turn the key to the on position , NOT START POSITION; while you quicklly test both contacts for 12v on fuse 13.
Do you understand?
Ok so I tested it while the relay and fuse were both in and on both contacts for the fuse I get a 12.5 volts while the key is in on position (no cranking) but only for a second then drops off to .1or so
Mike, could it be that you dislodged and electrical connector while removing the pump?
Well the problem only started after I changed the water pump put every thing back together and went to start it to pull out of the garage and that's when there was a problem I check all plugs that I unpluged in front of the engine maybe I got a bad sensor but not sure what they all are or how to check that there working properly
Well the problem only started after I changed the water pump put every thing back together and went to start it to pull out of the garage and that's when there was a problem I check all plugs that I unpluged in front of the engine maybe I got a bad sensor but not sure what they all are or how to check that there working properly
So take a photo of of the components that you removed and point to them.
Check to see that you installed the belt correctly.
Last edited by Maj. Dundee; 11-18-2020 at 03:20 PM.
When the eng. is cold, remove the cap at the fuel rail and press the valve in and catch fuel with a towel.
Install the gauge, and have someone turn the key to the ON position (NO START) and note the fuel pressure. What was it?. Then turn the OFF and keep looking at the gauge. Does the pressure drop slowly or quickly? Then after the expiration of 30 mins., what is the fuel pressure?
By the way, removal of the water pump does not call for removing any of those components.
Last edited by Maj. Dundee; 11-19-2020 at 07:52 AM.
When the eng. is cold, remove the cap at the fuel rail and press the valve in and catch fuel with a towel.
Install the gauge, and have someone turn the key to the ON position (NO START) and note the fuel pressure. What was it?. Then turn the OFF and keep looking at the gauge. Does the pressure drop slowly or quickly? Then after the expiration of 30 mins., what is the fuel pressure?
By the way, removal of the water pump does not call for removing any of those components.
I have a code reader I removed the sensors to open up the area more and I have took off the main fuel line going to the fuel rails to see if any fuel comes out of the line when I turn the key on nothing comes out and I don't have power running to the plug the plugs into top of the pump
F2 fuse #13 travels to X18 conn. A3 wire GREEN. Remove cover under left side Inst. Panel and locate conn.
Test both sides of conn. X18 wire A3 GREEN for 12v while eng. is cranked.
My ml350 is left hand drive so would it be on driver's side? This is my connector doesn't look like the same pin out as you gave unless I not looking on the right spot
11-09-2020, 01:48 PM
