Solved In serious need of help before i lose my truck having electrical issues

[410explorer]

So heres the deal i have a 96 explorer 4.0 with 197kmiles i never had a key fob since iv owned the truck a few days ago it was parked and a alarm started going off even though i didnt even know it had one then about two days ago i went to start tge truck but the battery was dead i jumped it got it running then my voktage climbed all the way to high and the battery light came on i ordered a new altenator but it took 3 days to get here and i had to still get nack and forth to work so then on day 2 it realky stared acting crazy windows stopped working licks woukd intermittenly work the tge compass dispmay started blinking and the truck shut down i had to have it towed the battery was fr i ed i brought a new battery and webt to start the truck but no fuel pressure so i figure ok welk i need a fuel pump i replaced fuel pump with no luck i realized i coukdnt hear it cone on with they key but if i jumped the relay terminals the pump woukd run but truck not start no spark so i checked around both fuse boxes i had power to all fuses but one under the hood the air bag fuse was blown and one in the truck the GEM fuse i reokaced both the gem fuse kept popping i jumped it with a wire and then GEM started to smoke obviously has internal short so i ordered a new one but i also realized when i turn the key to on i have no check engine light does this mean the pcm fried ? I cant see anyother readon theres power at distrubution box but no spark or fuel pressure unless the pcm just not asking for it

 

[410Fortune]

Wow

That is all one sentence

Quit throwing parts at it without doing some testing, you have not fixed anything and you are out hundreds of dollars

You replaced the fuel pump and there is still no fuel pump working because it’s not being powered up

Your gem module is fried because instead of finding out why the fuse is blowing you just bypass the fuse

Where to start now?
New battery
New alternator
New fuel pump

No cel with key on this is where I would start

Check pcm fuse and pcm relay this means checking for power with a multimeter or test light

You turn the key to on” the other eec relay should power up. Does it?

 

[410explorer]

Sorry im working on truck and typing i have been testing things i know the voktage regukator in altenator went out but when the truck died i replaced this it had gotten towed had to get it out of impound i made a rash decision with the fuel pump which other eec relay are you reffering too i have power across distibutiom box yes everywhere but im not exactky sure how to test the pcm electrical is my weak point im all ears to your suggestio where shoukd i test next

 

[410explorer]

When i turn the key to on im hetting no fuel pump power no matter how i switch the relays but if i jump the fuel pump relay it comes on but truck still wont start due to no spark its cranking with no spark or fuel pressure

 

[410Fortune]

The ignition switch powers up the eec relay

The eec relay powers on the computer and the computer then triggers the fuel pump relay

No cel when you turn the key to “run” usually means the eec relay is not powering up or you have an issue with the computer itself

The regulator went out in your alternator you said, did you know the regulator is powered via a 15 amp fuse? Did you check the fuse before replacing the alternator?
Was the alternator bench tested to be bad?

 

[Turdle]

Post 15 here might help

Solved - Fuse and relay locations--2nd generation power distribution box Layout-

I think this is a good sticky candidate-- Fuses are listed here * = maxi fuse 1*=50A I/P fuse panel 2*=40A blower motor relay 3*= 50A 4 wheel ABS module 4*=20a Main light switch-Instrument cluster 5*=50A Ignition switch, starter relay 6*=20A Transfer case relay 7*= NOT USED 8*=20A Auto Ride...

www.explorerforum.com

 

[410explorer]

That is exactly some of the info i was looking for and yes the 15 amp altenator duse in the distrubution box is good no the old altenator was not bench tested but i can do so now if it helps answer things i assumed being as the fuse was good but the battery light was on and voltage that was to high now im going to look for the eec relay how can i test it oh and its 4.0 i know the GEM was going bad because the inside controls acted possesed somtimes the windows woukd work then not somtines locks work then not the done light never worked since i have owned it

 

[410explorer]

The ignition switch powers up the eec relay

The eec relay powers on the computer and the computer then triggers the fuel pump relay

No cel when you turn the key to “run” usually means the eec relay is not powering up or you have an issue with the computer itself

The regulator went out in your alternator you said, did you know the regulator is powered via a 15 amp fuse? Did you check the fuse before replacing the alternator?
Was the alternator bench tested to be bad?

Hey im seeing so e cross information which one is the eec reĺay on a 96

 

[Turdle]

That is exactly some of the info i was looking for and yes the 15 amp altenator duse in the distrubution box is good no the old altenator was not bench tested but i can do so now if it helps answer things i assumed being as the fuse was good but the battery light was on and voltage that was to high now im going to look for the eec relay how can i test it oh and its 4.0 i know the GEM was going bad because the inside controls acted possesed somtimes the windows woukd work then not somtines locks work then not the done light never worked since i have owned it

Pics in that post need to be fixed. Hopefully that will happen soon. Not accurate yet, sorry.

However, before doing anything, get a volt meter. Check for 12 v on pcm relay socket with key on. You are trying to fix things that will not work without pcm power, so address this only.

 

[Turdle]

You might have killed gem by inserting a jumper in fuse. Never do that.

@410Fortune is gem needed to power pcm?

 

[Turdle]

Hey im seeing so e cross information which one is the eec reĺay on a 96

You were looking in 91-94 sub forum.

Pcm power relay. 96 up terminology.

Info you want will be in 95-01 sub forum.

 

[410explorer]

You were looking in 91-94 sub forum.

Pcm power relay. 96 up terminology.

Info you want will be in 95-01 sub forum.

So i checked for power at pcm relay its there i also see power at some ecm connector pins but when i turn the key to crank it cranks but no fuel pressure no spark i i het fuel pressure if i jump the fuel pump relay

 

[410explorer]

And what are these other relays under fender behind battery

 

[Turdle]

And what are these other relays under fender behind battery

Those are headlight and park light fog light washer pump relays.

Once again, if the check engine light is not on, the pcm is not on. No spark or fuel will happen until you get the pcm to turn on.

 

[410explorer]

Those are headlight and park light fog light washer pump relays.

Once again, if the check engine light is not on, the pcm is not on. No spark or fuel will happen until you get the pcm to turn on.

I completly agree turdke i just verified power at pcm relay with a test light theres power at the relay if i jump it i can hear a click but still no start im beggining to think my high voktage fried the pcm i seem to have power everywhere turdle where shoukd i go from here its parked somewhere it has to be moved i dont have the money for tow truck or impound the impound when it broke down and the parts ran me dry it was 600$ to get it back from impound im not sure where to test from here

 

[Turdle]

I completly agree turdke i just verified power at pcm relay with a test light theres power at the relay if i jump it i can hear a click but still no start im beggining to think my high voktage fried the pcm i seem to have power everywhere turdle where shoukd i go from here its parked somewhere it has to be moved i dont have the money for tow truck or impound the impound when it broke down and the parts ran me dry it was 600$ to get it back from impound im not sure where to test from here

I'd try a new gem from same year and optioned truck. You can't put the magic smoke back into it.

Time to hit a pick and pull. No quick fix sorry.

 

[Turdle]

Best to match part number on existing gem.

I do have one from a 98 but I doubt the numbers match. If they do though you could have it for ship cost.

 

[410explorer]

Best to match part number on existing gem.

I do have one from a 98 but I doubt the numbers match. If they do though you could have it for ship cost.

I really appreciate that offer but i got a famiky member to order me a number matching GEM remaned off ebay from a highly rated seller it wont be here until thursday

 

[toypaseo]

First thing I read… alarm going off.

Mine was going off for no reason. Replaced battery, never happened again.

 

[410Fortune]

Gem is not required for pcm functions no

The pcm/eec relay is powered directly from the ignition switch

I would not plug in the new gem until you figure out what it going on with the pcm power / check engine light

Do you have the correct wiring diagrams now? You need to test the power and signals at the pcm relay (also called eec and ecm sometimes)
The ignition switch is on your steering column. It is controlled by the key and tumbler. It sends power to the pcm relay to power on the computer
The computer then triggers the fuel pump relay

You need the pcm relay wiring info so you can test not only battery power but also the signal coming from ignition switch

No cel at first turn of the key, this is the first thing you must solve

Forget about dome lamps and door locks until we have spark and fuel