91 ford explorer fuel pump hook up wrong?

[lofton316]

91 exp fuel pump hooked up wrong?Almost Fixed!

I had two fuel pumps installed last year, since then there has been a slow start in the morning, have to crank the engines a few times to get it started, could take up to 10 minutes doing it, but if it turn the ignition on and off real quick i could get it to start in less then 3 seconds. Now i was wondering if my fuel pump is could have something to do with it, the red wire from the pump i guess is hooked up directed to the fuse pump under the steering wheel. The red wire is wrapped around a yellow fuse 20 i think, when i take it out the fuel pump doesnt come on. Could this be cause my slow start in the morning, once is ran for a while it will start right up for a few hours. Then once i let it sit the same problem, all started after the fuel pump was changed. starter silionoid has been changed.ignition switch has been changed but not the key part.

Edit
here are the pics
here are the pics
this is where the red wire is

and this is where it goes

 

[cloaked_chaos]

Sounds like the check valve to me.

 

[lofton316]

Sounds like the check valve to me.

so the fuel pump could be bad ??

 

[TedJ]

I'm having a little trouble understanding original post... did you mean to say that there is a wire that goes to the fuse panel and is wrapped around one end of a fuse? i.e. some kind of jurry-rigged setup? or am i misunderstanding that?

Is the pump running for a few sec when you turn the key on?

-Ted

 

[lofton316]

I'm having a little trouble understanding original post... did you mean to say that there is a wire that goes to the fuse panel and is wrapped around one end of a fuse? i.e. some kind of jurry-rigged setup? or am i misunderstanding that?

Is the pump running for a few sec when you turn the key on?

-Ted

Yes there is a red wire coming from the fuel pump that is wrapped around the fuse, then. Once the accessory come on or the ignition switch is turned on half way the fuse pump runs, the old stock one use to run for a few seconds but the new one stays on constantly when it gets power. So im guessing its not suppose to be hooked up that way

 

[TedJ]

Um... yea its really not supposed to be hooked up that way... I have no idea why it would be like that.

Since the fuse has power in run and acc, it means that the pump runs constantly if you're listening to the radio, etc w/o the engine running. Not only will that drain the batt, its probably not too good for the pump either.

I'd bet that the fuse has power in run but no power while cranking. If you stick a test light beteween that fuse and ground, and crank the engine, I'll bet you have no light while its cranking (but light on in acc or run) If thats true, then every time you're starting it you're depending on residual pressure b/c the pump isn't running while cranking. If you keep turning the key on and off it will build pressure every time the key is passing by run on its way to the crank position, and eventually you will get enough gas into the engine to start it. When its hot, there is allready some built up pressure in the lines and a hot engine also doesn't take as much gas to start, so it will start up more easily on the residual pressure.

I would get it rewired the right way as soon as you can. Its not doing your pump, wiring, or starter/engine much good the way it is.

-Ted

 

[lofton316]

Um... yea its really not supposed to be hooked up that way... I have no idea why it would be like that.

Since the fuse has power in run and acc, it means that the pump runs constantly if you're listening to the radio, etc w/o the engine running. Not only will that drain the batt, its probably not too good for the pump either.

I'd bet that the fuse has power in run but no power while cranking. If you stick a test light beteween that fuse and ground, and crank the engine, I'll bet you have no light while its cranking (but light on in acc or run) If thats true, then every time you're starting it you're depending on residual pressure b/c the pump isn't running while cranking. If you keep turning the key on and off it will build pressure every time the key is passing by run on its way to the crank position, and eventually you will get enough gas into the engine to start it. When its hot, there is allready some built up pressure in the lines and a hot engine also doesn't take as much gas to start, so it will start up more easily on the residual pressure.

I would get it rewired the right way as soon as you can. Its not doing your pump, wiring, or starter/engine much good the way it is.

-Ted

WOW WHAT YOU JUST SAID IS EXACTLY WHATS HAPPIN, THAT WOULD EXPLAIN WHY ITS EASIER TO START IN THE SUMMER THAN THE WINTER, So much have been replaced. I just noticed the way the fuel pump was hooked up about 6 months but i didnt think anything of it. So i need to get the wiring correct can i do that myself, is there awire i can hooked that red wire thats wrapped around the fuse to another source? or would it be better to get the whole thing done professionally. I think you just saved me a ton a money on guesses! It was just about to go in the shop yesterday, but if i can do that myself i can prevent that. Its scheduled to go in for repair monday but they have to find out whats wrong which would probably be alot of money.

 

[shamaal]

You want figure 7.

http://autozone.com/servlet/UiBroke..._us/0900823d/80/0b/a9/c7/0900823d800ba9c7.jsp

The box in the left center of the page titled Fuel Tank Unit is the pump (labeled M) in the gas tank.

Ask question, fuel pump problems are well researched.
FWIW, the Inertia Fuel Cutoff Switch is on the floor on the passenger side just under the top of the carpet.

 

[TedJ]

I'd say that you need to get it hooked back up the way it's supposed to be. Autozone has some halfway decent wiring diagrams but they're lacking in places. If you're gonna try it yourself, i have the Ford 93' to 94' service manual on cd so I can get you the real schematics if they will help. I'd rather not try to come up with some kind of half-assed fix for this, b/c when your truck burns down or you get stranded in the middle of nowhere its not worth jurry-rigging it.

I'd first off try to see where they hacked into the wiring to add the red wire you're talking about. It shouldn't be too hard to see what is factory and what isn't. Put everything back to the way it was factory (do it well, solder and shrink wrap), then start looking for reasons why the factory wiring doesn't work. Check the inertia switch and fuel pump relay. Make sure the relay is being triggered by the ecm. Look for melted wires and blown fuses. The fuel pump circuit isn't that complicated so I'm suprised someone took the time to hack it up instead of just fixing the original system. A lot of times its more obvious than it would seem. A good DVOM or test light will help a lot.

-Ted

 

[lofton316]

here are the pics
this is where the red wire is

and this is where it goes

the bundled red and black wires in the first pic is from the radio to the amp

 

[TedJ]

oof... that is a pretty bad hackjob. That wire looks pretty thin to be powering the fuel pump... I cant figure out for the life of me where the 2nd pic was taken. Is that by the side of the frame or ???? I cant visualize what that thing is in the pic. It looks like an alarm siren? Maybe that's why I can't figure where that would be..there's nothing recognizable there. If you could take a pic of the general area where the 2nd pic was taken that would help.

Did you check if your fuel pump relay/inertia switch are there and look ok? Did you check to see if the relay is getting B+ and triggering voltage from the ECM?

-Ted

 

[mikeinri]

Especially now that we've seen the pictures, I agree with the posts above and urge you to get this back to the stock configuration as soon as possible. There are too many stories of burning Explorers due to wiring mishaps.

Buy a good wiring diagram and get ready to spend some quality time getting to know the nether regions of your truck more intimately...

Mike

 

[lofton316]

oof... that is a pretty bad hackjob. That wire looks pretty thin to be powering the fuel pump... I cant figure out for the life of me where the 2nd pic was taken. Is that by the side of the frame or ???? I cant visualize what that thing is in the pic. It looks like an alarm siren? Maybe that's why I can't figure where that would be..there's nothing recognizable there. If you could take a pic of the general area where the 2nd pic was taken that would help.

Did you check if your fuel pump relay/inertia switch are there and look ok? Did you check to see if the relay is getting B+ and triggering voltage from the ECM?

-Ted

Thanks Ted and Mike, sorry about the second pic, i thought about the same thing about not being able to figure out where it is. that is the driver side rea fender area, the red wire goes through the back of this hole behind the fuse box under the dash., that speaker thing was apart of the alarm but was but that was unhooked. When you unplug the red wire, the fuel pump does not come on. The inertia switch doesn't even work anymore, its like its not even hooked upor been bypassed. I am so mad! This was my mothers truck but she got another car after a year because the thing would take forever to start but when it was towd back to the shop that did it the car started right up and they said it was fine. The car is in a new shop now. I was trying to tell them what the problem was and they had this look on their face like it was crazy what i was describing and could be hell fixing it.

 

[UKExploder]

I have 'rigged' a few vehicles in my time & can honestly say the wire that is being used to power the fuel pump is too small. You could just get a good toggle switch & some heavier duty wiring, hook up the red wire to the battery instead of under a fuse & turn the fuel pump on when just before you start the truck and remember to turn it off when you turn the engine off, if you want to really save a lot of cash. I had a Ford Courier pickup that this was how the factory had wired the electric fuel pump.

 

[lofton316]

I have 'rigged' a few vehicles in my time & can honestly say the wire that is being used to power the fuel pump is too small. You could just get a good toggle switch & some heavier duty wiring, hook up the red wire to the battery instead of under a fuse & turn the fuel pump on when just before you start the truck and remember to turn it off when you turn the engine off, if you want to really save a lot of cash. I had a Ford Courier pickup that this was how the factory had wired the electric fuel pump.

Some how that wire is powering it! Its been in the shop for 6 days now, and no word from them...I'm going to have to call them today!:exp:

 

[BluOvalMan]

What it sounds like, is that sometime in the past, the Fuel cut-off switch was tripped or the fuse went and someone hacked the RED wire to a fuse and spliced into PUMP power wire. If the current shop hasn't fixed it yet, I would get it out and check a couple things yourself.
I would start by tracing the RED wire to see if it is spliced or Cut & Crimped to the Pump power wire. Fix that how ever it was done. Then make sure your fuses are all good, even the box under the hood. Basically Isolate everything one at a time till you find the fault. Couple hours on a Saturday morning and I think you would be pretty proud of yourself for fixin it and saving the cash.

 

[lofton316]

What it sounds like, is that sometime in the past, the Fuel cut-off switch was tripped or the fuse went and someone hacked the RED wire to a fuse and spliced into PUMP power wire. If the current shop hasn't fixed it yet, I would get it out and check a couple things yourself.
I would start by tracing the RED wire to see if it is spliced or Cut & Crimped to the Pump power wire. Fix that how ever it was done. Then make sure your fuses are all good, even the box under the hood. Basically Isolate everything one at a time till you find the fault. Couple hours on a Saturday morning and I think you would be pretty proud of yourself for fixin it and saving the cash.

Thats what i figured, The shop or who ever did that ran into a blown relay or fuse (all of the fuses were replaced) and instead of waiting a few weeks to order a new ford relay switch(cause everyplace around here doesnt have it and u have to order it) and hacking into the fuel pump circuitry was an easy way out. I believe i can fix this truck. I have access to a 93 ford explorer that has been sitting in a yard since last july since the tranny seal broke, the relays all work on that but i couldn't get the hood open before the car was put in the shop. But Imma give them to the end of the week, then im pulling it.

The hood in the 93 was bent in a fender bender so the hood release switch is a little screwy but that might be my best bet. Thanks guys!

 

[lofton316]

Success!!! well not quite. I picked the car up from the repair place. They werent able to find the problem even though I told them what i thought it was, i guess the miss understood. But got the to place, went to start the car after it sat over night, and bam it started right up like nothing was wrong with it! But it was like 70 saturday so the heat must of caused the pressure to build up in the tank i guess I didnt have time to look at it then cause i had to go straight to work. The red wire they ended up taken up the door trim and the side panel and carpet tracing this red and black wire. The one in the picture behind the fuse panel, that wire was to the amp. I guess i should of told them that They didnt even leave the screws to put the panels back. The red wire going from the fuse box to the fuel pump wiring was not touched.

I would of worked on it today but its been raining and flooding so Im going to have to wait until later on in the week when its clear and sunny to work on it. But i did alittle test. This morning it was cold close to freezing, so i tried to start it and of course it didnt start, so about 8 hours later came back home, still cold, took the red wire from the 20amp fuse and hooked the red wire up to the 20amp fuse on top of that one which is on constantly, even when the car is cranking, so i put it in there, and the fuel pump came on without the ignition turned. So i go to start the car and Success!!!! Car started right up.

So I Know what i have to do. I have to undo that electrical tape where that red wire goes and see what they did, hopefully they just cut the wire factory
wire into and clipped the red wire to the other half. If so then I will get the factory wiring hooked back up. The fuel pump relay was changed with a new one so everything should work. If that doesn't work i guess i will test those relays out again, until then Im just gonna have to keep the wire plugged into the 20amp fuse that continues to have power even when the car is off, and just turn the fuel pump on when needed. But also I need a bigger wire cause like someone else mentioned it is to small to deliver full power to the pump when starting.

I wouldnt of been able to do this without this forum. Thanks!

 

[lofton316]

Toggle switch installed. Took the red wire out that was powering the fuel pump and replaced that with a heavy gauge wire and plugged that into the 20amp fuse that has constant power to it,. Let the car sit out over night, flipped the switch and success the car started right up. I also went and got a new fuel pump relay and put that in there but the fuel pump didn't work without its hacked lifesupport wire, There is another relay right next to it that is looks messed up but i dont know what relay this is. But i don't know what else could be cause the fuel pump not to get power, when i took the tape off the wire it was still connected to its original wire, the casing was just stripped and that red wire was tied around it. I guess i gotta look for a burnt wire or something? the button on the inertia switch is pushed down so its not that.

 

[shamaal]

Relays are Fuel Pump, EEC Power and Wide Open Throttle (WOT). I don't recall order.

Two risks that I see to to your current setup:

1. In the event of an accident you will still be pumping fuel until switch is turned off.
2. If injector leaks or gets stuck, cylinder will fill up with fuel. Liquid fuel does no compress.