2.3L ('83-'97) Electrical Problem I can't figure out.

[ABSOLOOT LOONASEA]

I suggested the chassis/rear lamp harness because you have lost all electrical functionality to the rear of the truck. I try to look for single points of failure.

You could jump the fuel pump relay just to see if the pump runs. It doesn't have to be at the diagnostic connector.

I will look at my diagrams tomorrow and try that, thanx Uncle Gump.

 

[ABSOLOOT LOONASEA]

it’s a simple test plug and will allow you to hot wire the pump but I believe your issue is elsewhere. You mentioned your ignition switch was unplugged and you thought you hit the sweet spot. That’s where I would go first. If it’s not on squarely only some things will work. Said from experience. Stay tuned. Standing by.

Yeah, I've been thinking about that, I've got a new ignition switch, I think I'll put it on the column and then try for the sweet spot again. I thought for sure I had the right spot when I turned the engine over and then went to the accessory position and it worked too. I'll do all that tomorrow and I'll let you know how it goes. A friend of mine came over and tested the ign. switch (the wires coming off of it) with a test light, key on, and all the wires were hot he said, but I'll put on the new switch and do the search for the sweet spot again.

 

[RonD]

I think the tail lights are an unrelated issue to the fuel pump

That's why I suggested the jumper wire to see if you could get the fuel pump working first

It would be the easiest thing to try, once you found the connector, sorry I should have said it could have a cap with EEC on it, rare to find a 1990 Ranger with that cap still in place

 

[ABSOLOOT LOONASEA]

I think the tail lights are an unrelated issue to the fuel pump

That's why I suggested the jumper wire to see if you could get the fuel pump working first

It would be the easiest thing to try, once you found the connector, sorry I should have said it could have a cap with EEC on it, rare to find a 1990 Ranger with that cap still in place

Not a problem RonD, you've helped me a lot already, going out in a few to try that. Thanx again, Loonasea

 

[ABSOLOOT LOONASEA]

Yeah, I've been thinking about that, I've got a new ignition switch, I think I'll put it on the column and then try for the sweet spot again. I thought for sure I had the right spot when I turned the engine over and then went to the accessory position and it worked too. I'll do all that tomorrow and I'll let you know how it goes. A friend of mine came over and tested the ign. switch (the wires coming off of it) with a test light, key on, and all the wires were hot he said, but I'll put on the new switch and do the search for the sweet spot again.

Not a problem RonD, you've helped me a lot already, going out in a few to try that. Thanx again, Loonasea

I did the jumper wire trick and I heard my new fuel pump run for the first time at least now I know it works!!!

 

[ABSOLOOT LOONASEA]

Not a problem RonD, you've helped me a lot already, going out in a few to try that. Thanx again, Loonasea

Did the jumper wire trick and heard my fuel pump run for the first time, AND IT WAS GOOD!!!! Thanx man!!! Should I concentrate now on the ign. switch?

 

[RonD]

Engine should start and run with jumper in place, doesn't hurt any thing, the jumper is just doing what the Computer does, it grounds the fuel pump relay

 

[ABSOLOOT LOONASEA]

it’s a simple test plug and will allow you to hot wire the pump but I believe your issue is elsewhere. You mentioned your ignition switch was unplugged and you thought you hit the sweet spot. That’s where I would go first. If it’s not on squarely only some things will work. Said from experience. Stay tuned. Standing by.

I did the jumper wire trick

Engine should start and run with jumper in place, doesn't hurt any thing, the jumper is just doing what the Computer does, it grounds the fuel pump relay

Gonna go try that right now!!!

 

[RonD]

Ignition switch doesn't turn on the fuel pump, it turns on the Computer, and the computer turns on the fuel pump(grounds relay), but just for 2 seconds

 

[ABSOLOOT LOONASEA]

I did the jumper wire trick

Gonna go try that right now!!!

EUREKA IT RUNS!!!!!! running a bit rough but it's running none the less, should I go back to the ign. switch now?

 

[ABSOLOOT LOONASEA]

EUREKA IT RUNS!!!!!! running a bit rough but it's running none the less, should I go back to the ign. switch now?

Or, should I check something else first?

 

[ABSOLOOT LOONASEA]

Or, should I check something else first?

While it was running the check engine light came on and so did the brake light. Now I need to pull a code!?

 

[ABSOLOOT LOONASEA]

Engine should start and run with jumper in place, doesn't hurt any thing, the jumper is just doing what the Computer does, it grounds the fuel pump relay

Truck is running for the first time in 2 years with the jumper in place, the check engine light came on along with the brake light and the rear anti-lock light and the fuel gauge isn't working. It's got a rough idle but that's ok for now IT'S RUNNING, that's the main thing. Had a lifter ticking for a while but it has smoothed out a little,, idle is better but still not right. I've got it running now coming up to temp. so I can pull a code. I'll let you know fwhat I come up with, and thanxx again my friend.

 

[ABSOLOOT LOONASEA]

Truck is running for the first time in 2 years with the jumper in place, the check engine light came on along with the brake light and the rear anti-lock light and the fuel gauge isn't working. It's got a rough idle but that's ok for now IT'S RUNNING, that's the main thing. Had a lifter ticking for a while but it has smoothed out a little,, idle is better but still not right. I've got it running now coming up to temp. so I can pull a code. I'll let you know fwhat I come up with, and thanxx again my friend.

OK, where I'm at now. I tested the FP relay and it clicks, did several other tests including inertia switch and they were good, then...I grounded my test light to the battery and put the probe into the slot for #1 and I have a very dim light. I turn the switch on and the light goes out, Tried turning the engine over and the same thing, the light goes out. I then put the test light on slot for wire #2 and have a dim light, turn the switch on and the light goes out again. Could that mean that my computer is fried?

 

[RonD]

Slot #1 and #2 ???

Its a big truck, electrically, lol

Ford used two types of relays
Micro, seen here: http://www.gtsparkplugs.com/images/micro-automotive-relay-wiring.jpg

And Mini, seen here: http://www.gtsparkplugs.com/images/mini-automotive-relay-wiring-840x.jpg

These are the pin/slot numbers you should use for relays as they are common/standard
Ford used 1 to 4 or 5 but it changed all the time, lol, so not at all standard

85 and 86 are often 1 and 2 on Ford diagrams, one needs to be 12v and the other a ground for relay to activate
There is no polarity assigned, either can be 12v and the other the ground, but there must be both to activate relay

Many Ford(GM) relays are Ground activated, so relay gets 12volt with key on, but the computer or a switch activates the Ground to activate the relay
This reduces the 12volt wiring in a vehicle, so reduces the chances of a short
If a ground wire shorts a device/relay just activates
If a 12v wire shorts a fuse blows(best case) or wires start to smoke and melt(worst case)