mesadad

So, my sons 2007 GT Stang had a slow drain on the battery. Also the blower fan quit working. Bought a new battery and replaced the blower resistor. Fan started working. Not great but worked. Made some squeaking noise so i ordered a new fan. Son drove the car to work. Snow and Ice formed that night. He got off work and warmed up the car. Fan didn't come on. Ice was forming and it was a long drive home. Bought a new fan and installed it. Fan won't come on. Checked fuses and relays. All good but no power to the blower fan resister. Checked connections but nothing out of the ordinary.
Forgot the key was on and started to unplug connector in front of SJB. Everything went off. Plugged it back in and no dash lights no crank no start. DEAD. Left the battery unplugged over night. Came back out the next morning, connected battery and turned the key. Dash lights and HVAC controls worked, except for the blower fan. Went to start the car and it just cranked. Realized the fuel pump is not activating. Fuses are good and relays seem ok. No voltage to the pump, none at the Driver module in trunk and no power at the inertia switch, left side kick panel.

So, does the SJB control any part of the fuel system? None of the schematics i've seen show the SJB controlling the Fuel delivery. Now a few years ago water got into the passenger side, via the vent in firewall. Water may have gotten onto the SJB but everything still worked. Did i miss something? could it be the SJB? How? why?

Troubleshooting the crap out of this thing and it's driving me crazy.

Any help is greatly appreciated. I've googled, yahoo'd, and binged everything i can find but no followups and no conclusion.

Derf00

check for water infiltration from these areas:

https://latemodel.cachefly.net/downl...sb08-26-07.pdf

There's also a possibility that there is water getting trapped in the firewall of the car and eventually ending up in the passenger compartment near the HVAC stuff that could be causing a short. If you remove the passenger side cowel under the windshield outsidewhere the Air Cabin filter is, directly under the Air Cabin filter holder is a rubber grommet (about foot down the firewall) that often gets plugged with leaves etc. This prevents water from draining out.

Check the SJB fusebox in the passenger kick panel as well for any signs of corrosion or rust or water.

Most if not all of that is in the TSB.

mesadad

Thanks for the info. I knew about the water leak but never saw the TSB, so thanks. About 2 years ago my son lived in Houston and they had major rain storms. He had a lot of water in the passenger side floor board. But, up until now, the car ran great. When i checked the SJB, i pulled the connector off and saw the corrosion. I cleaned out what i could and re-installed it. blower still didn't come on. So i went to check the white connector in front of the SJB, the one with the palstic clamp.(don't know the number of it) i lifted the clamp to unplug it. Forgot i had the key on because i was checking for voltage, then everything went off. I realised what i did so, with the car off, i reconnected it, turn the key to the "RUN" position and nothing. DASH lights, HVAC, NOTHING. Unplugged the battery and came back the next day. Dash lights came back, HVAC temp buttons worked, except for the blower fan. Turned the key and only cranked. Tried again and realized no sound from the fuel pump. Started checking fuzes, relays, interita switch and driver module. I'm only getting .33 volts at the driver module and same at the interita switch. So what part of the fuel system runs through the SJB? i see nothing in the wiring diagrams that the fuel system receives a signal from it.
So if the fuel system operation does not rely on the SJB, where do i go from here? I'm at a loss. short of tearing everything out of the dash, i'm stumped. One thought is, the previous installed a Viper Alarm. It does prevent the car from starting if its not unlocked with the remote, but the fuel pump would still prime with the key in the run position. If i could find where the control box for the alarm is installed, i would disable it.

I'm sure the SJB has some water damage to it and i'll probably replace it just to be safe. But again, the car has been running great up until i unplugged that one connector.

tw1234

Check Fuse 19-5amp in SJB. It controls the PCM Relays. It supplies power for the pull-in coil connection #85 of the fuel-pump relay. It should be Hot in Start or Run.

mesadad

thank you for responding. I went back and read some forums to get some other ideas. I read one about a 93 Ford Ranger that had the same problem. He used a jumper wire in place of the diode in his fuse box and his pump came on. So I went back and checked both of the diodes. Both checked good. However I noticed that one was turned the opposite direction of the other. So I turned it around to match the other on,(upside down) and I’ll be damed the pump came in and it fired right up.

tw1234

Was the diode removed before and reinstalled backwards?

mesadad

You bet I did it was totally my fault. Initially I was troubleshooting the blower fan that quit working. Not realizing that while checking all the fuses I pulled the diode and reinstalled it in reverse. Nothing on the BEC indicated the direction the diode should go. Common sense tells me to put it back with the number reading left to right. With that said, I now have to ask why didn’t ford design the fuse box so that all the relays go in one direction? Guess we’ll never know. I’m just relieved everything is working now. As for the blower fan, it turned out that the new blower resistor I put in went bad because the blower motor was straining to turn and drew too much power. So I replaced the blower motor and got a new resistor and she works. Lots of lessons learned from this and I’ve created my own little “smart book” of lessons learned from this.