Progress Thread Talk about an oh shiiiiiiaaaaat moment!!

Reddevil91

5 Year Member
Mar 3, 2010
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Ok guys so I need to change my fuel filter being that it hasn’t been changed in a long time. My question is do I need to depressurize the system? I’ve seen ppl do it by the schrader valve on the fuel rail but I have my fuel gauge on that area.
 
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Mustang5L5

Mod Dude
Feb 18, 2001
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Unplug eithe the fuel pump relay or the inertia switch and run the engine until it no longer will run.

Some older pumps have check valves that aren't as efficient so you wait 10-15 mins the pressure might drop to 0.

You still get some leakage, but much less than if you crack a line without relieving pressure a bit
 

Reddevil91

5 Year Member
Mar 3, 2010
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Unplug eithe the fuel pump relay or the inertia switch and run the engine until it no longer will run.

Some older pumps have check valves that aren't as efficient so you wait 10-15 mins the pressure might drop to 0.

You still get some leakage, but much less than if you crack a line without relieving pressure a bit
Cool I have a new aero 340 in the tank now, so this won’t obviously damage anything? By the relay it’s the one under my seat correct? I have a 91
 

Mustang5L5

Mod Dude
Feb 18, 2001
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No power means the pump doesn't run so you just run the engine on residual pressure. Obviously iywont run long, but it does relieve some of the pressure in the lines.

Unsure how well the check vakve is in the pump. With my 190 walbro, pressure is 0psi less than 15 mins later
 
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Reddevil91

5 Year Member
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No power means the pump doesn't run so you just run the engine on residual pressure. Obviously iywont run long, but it does relieve some of the pressure in the lines.

Unsure how well the check vakve is in the pump. With my 190 walbro, pressure is 0psi less than 15 mins later
Thanks for the info, had a friend that changed his and I don’t think he depressurized his or maybe he did but it splashed him real good when he disconnected and got gas in his eyes and ears!! Trying to avoid that situation.
 

Shakerhood

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Oct 28, 2004
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I usually change the fuel filter in my car after it sits for a few days then the system has pretty much no pressure, I also stick vacuum plugs on the old filter as I am removing it as it lessens the amount of fuel spilling out.
 

Reddevil91

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Ok my friends so I did this wiring trick many years ago that I read in the older 5.0 magazines to try and run the fog lights with out having the headlights on. I cut and spliced and jabbed a wire into the fuse panel and one grounded to a screw. Idk honestly bc not real sure what exactly I did but basically my fog lights didn’t work so I’ve just left them be. But..... now I would like them to work as in changing out all the headlights etc. How can I fix this wiring/relay mess? Should I just get rid of that mess with the relay, and re-connect the two wires for the fog light connector? The two open wires with electrical tape were the ones that were grounded and one in the fuse box.
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02 281 GT

Agreed...My wife has great Boobs
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It looks like at some point you modded the headlamp circuit to run off a relay rather than directly through the switch. That's a worthwhile modification that I would keep. Best bet is to get your hands on an EVTM for your model year and a multimeter and sort out what's what in that harness.
 

Reddevil91

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Mar 3, 2010
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I found this article and I want to say it is similar but they did something different down at the fogs bc mine wasn’t wired that way. I’m just trying to figure out the best way to wire this up and hopefully get my fog lights to work. Also saw a different wire up where they just did an add a circuit which on saw on brew2l YouTube.
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Reddevil91

5 Year Member
Mar 3, 2010
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It looks like at some point you modded the headlamp circuit to run off a relay rather than directly through the switch. That's a worthwhile modification that I would keep. Best bet is to get your hands on an EVTM for your model year and a multimeter and sort out what's what in that harness.
Hmm ok I just posted an article I found which they did pretty much the same thing. Just not sure where I went wrong. Maybe I’ll find the link and post it.
 

Reddevil91

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02 281 GT

Agreed...My wife has great Boobs
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Feb 3, 2009
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Wichita Falls, TX
Hmm ok I just posted an article I found which they did pretty much the same thing. Just not sure where I went wrong. Maybe I’ll find the link and post it.
I see now. I'm wrong about the headlight relay thing. Looks like you tried to do what was said in that article. However, the relay you used looks slightly different than the one they did.
 

Reddevil91

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Does someone make a female plug for the relay that would clean up the spade mess?
I have no idea what I even did here. I tried this many years ago at some point based off an article I saw in 5.0 mag which is about the same as the one I posted out of the mm&ff. I’m almost thinking about maybe rewiring it back to stock with the two wire connector for the fog light switch then popping in an add a circuit kinda like this guy did as well as brew2l
View: https://youtu.be/uhXRrbwTLdg
 

90sickfox

I didn't really have an issue with the stink...
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The only downfall I see with that is if the fog lights and the radio are on it could overload the ( intended 15amp circuit running to the fuse box.

The issue with the old wiring is that there was no relay in the circuit. All newer cars have seperate relays for high, low, and fog. The reason for that was the amount of load a bad bulb can put on the switch circuit wiring. I have 04 cobra fog lights but utilize a relay and a factory fog light switch. Works like a charm. The 15amp circuit the fuse buddy is plugged into was never meant to carry 30amps.
 

Reddevil91

5 Year Member
Mar 3, 2010
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The only downfall I see with that is if the fog lights and the radio are on it could overload the ( intended 15amp circuit running to the fuse box.

The issue with the old wiring is that there was no relay in the circuit. All newer cars have seperate relays for high, low, and fog. The reason for that was the amount of load a bad bulb can put on the switch circuit wiring. I have 04 cobra fog lights but utilize a relay and a factory fog light switch. Works like a charm. The 15amp circuit the fuse buddy is plugged into was never meant to carry 30amps.
So you think running the add a circuit like in the video may end up overloading? I tried that setup in the other article but for whatever reason it didn’t work, unless some where else down the wiring to the fogs something is messed up.
 
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Reddevil91

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Well i am in a mix of redoing the headlights since a buddy hooked me up with a set in a gift exchange. Car is a mess right now bc I also started into another project as well. Decide to rid of that mess of wires and relay, re-connect the original fog light harness, plugged a 15 amp fuse back in and well damn we have power. So all new headlights, I ended up dropping one of the fog lights, which led to a lot of cursing but a new one is coming in. I changed everything out to LEDs, head light, parking, turn signals etc front and rear, fog lights, even added some to the heater ac area. Now I think I’ll try the add a circuit this weekend and see how that turns out to make the fog lights work independent.
 

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