Cooling Fans run all the time

2010 nissan sentra has a no Start no Communication noticed that cooling fans run all the time though..
Should I stop fans from running all the time first then see why it won't start .?
there wasn't a problem until my friend changed his fuel pump himself and
Now it won't start and has no communication
Before he changed the fuel pump it ran , now it has 1.3 at the reference wire and 12v at signal wire

I would start with the No Communication. The cooling fans running, and the starter not cranking ( I am assuming that it is a No-Crank, No-Start? ) could be a symptom of the communication problem.

Disconnect the battery and check the resistance between pins 6 and 14, at the DLC. You want to see 60Ω.

Diagrams are attached, below.

I agree with Chad. Chase the no comm first. The fans running constantly is a symptom of the IPDM losing communication.

Changing the fuel pump shouldn't have installed any problems by itself. Was he doing any other testing prior to the pump replacement? What was the original symptom?

Car kept blowing low beam fuse .
Found out today it's a salvage that had front end smashed in and fans were connected where they found power with no regard for where or to where it was going aslong as fans came on there is one Blue with black stripe wire connected to a white with black stripe wire
Another white with black stripe wire connected to a solid white wire both connected to power distribution box.
I looked at wire díagram and it's just don't seem right could that be cuasing the problems also?
Went out this AM and moved wires at ECU now I have 12v at MAF also ..

Fans running on high (even with the car off) and no start are the default when the CAN hi network is down. Not sure if the fans are on with the car off too.

Start with chads suggestion at the DLC.

Yikes, I just saw the picture of the wires. This is gonna get good...

In addition to have 60ohms at the DLC with the battery neg cable off, with the battery connected you should see 2.75v on the can high line and 2.25v on the can low. The values have to be very close to these numbers on your voltmeter.

Nissan Technician

Okay so today I downloaded a Nissan service manual for the 2010 Sentra as I was going thru the procedures I raised the vehical to check grounds underneath it was then that I realized that the steering doesn't lock and the windows work even with ignition key in the off position I get no voltage at the S terminal of starter solenoid during crank or with key in ON position I had the same problem with an F-150 it turned out to be a bad ignition switch mainly the little plastic ring at the entrance ofm the switch that reads the key everything was pointing at a bad ECU but now I'm not so sure at $238 for a ECU or $230 for an ingition and then to be wrong I would appreciate a second, third or fourth opinion.
( although his ingition will eventually go out due to it already not locking)
Should I test the knock Sensor I still have no communication but with the rats nest of rewiring that was done I dought I will
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Ok will re-check those numbers and get back as of yesteday they were 1.75 on both and 11.5 on the reference with battery connected but I do know now all grounds are good ..

I would Check the pins on the fuel pump connector. He may have bent the connector pins when connecting it. It sounds like a short to battery voltage. hopefully you didn't fry that computer because any voltage on a reference wire to PCM will fry the driver.

Thank You
Im still fighting with this thing, Kind of gave up on getting it started and just started to rewire the wiring harness in the engine compartment because it's a mess and I wanted to rule it out (I don't know how the vechical even ran but it did for a year )until I could get some more feedback and fuel pump was just the feedback I was hoping for (rewiring gives one time to think)and the fuel pump was gonna be what I checked next (when it should of been what I checked first ) I'll check that today and let you guys know...