After looking for a while, I've finally come up with an issue that has forced me to ask for help...

The Ranger is my son's and he is learning the ropes of auto repair on it. He went to install a pa system and had to have knocked something loose... The engine cranks but isn't getting gas. We pulled the filter and tried to see it would flow. It didn't.

While the fuel pump could have just gone out, I think it is an electrical issue. The OBD tool will power up but the screen says it isn't connected.

We've checked and replaced the fuses and fuel pump relay.

Does anyone have an idea of where wiring under the dash could have come loose at?

 

Welcome to the forum

What YEAR Ranger?

Also good to included which engine size as well

Does the CEL(check engine light) come on when you turn on the key?
If not then computer is not booting up, so no fuel pump and no OBD

Without the year I can't go much farther, just too many differences between 1983 to 2011

 

Sorry for leaving out the needed info... 1999 2.3 engine.

CEL does not come in when trying to start.

 

CEL should come on with Key ON, it will go off when starter motor is active

So does CEL come on with key ON, just key on

No 1999 2.3l, there was a 2.5l 4cyl?

 

No, the CEL does't come on. 2.5l engine. 2wd, manual.

After tour first comment, I took the GEM out, checked all of the wires and everything there. They seem solid. It doesn't look like there is a good way to test the unit itself. Do those units just go bad? I suppose he could have fried it trying to connect the PA system. My son's initial plan was to connect it to the power wires for the radio since he would only be using one or the other (we've pulled the PA system out until we resolve the issue).

I prefer the old school carb engines and lack of computers! :)

 

Yes, the 2.3l Lima engine was last made/used in 1997 Rangers, a new stroked version, 2.5l Lima, was used in 1998-2001 Rangers, then Rangers got a 2.3l Duratec engine in mid 2001

So your computer is not powering up, nothing to do with GEM module, that just runs cab lights and wipers

In the engine fuse box there will be a PCM Relay and PCM fuse, when you turn on the key the PCM relay should "click"/close and send 12volts from PCM Fuse to the PCM(engine computer), its in engine bay upper firewall near the center, has a 104 wire connector

So you need to find out why the PCM is not getting power, no CEL

First stop is to check that fuse and that relay

Do the other dash instrument lights come on with key on and then go off, there is a Bulb Test with key on
If not then the ignition switch under the steering column could be the problem, its above gas/brake pedal area
If dash lights come on with key on then thats not the issue

 

I appreciate the help...

Everything works in the dash. Lights, fuel gauge, etc. The only 2 issues are that it won't start ( cranks but not getting fuel) and the OBD scanner powers up but won't connect.
​​Fuses are all good
PCM relay does not have power to it. Both with key on and key off. Fuel relay has 12v.

 

Fuses and relay are good. I replaced them to make sure. I'm not hearing the clicking sound.

Dash and instrument lights come on (except for CEL) with key on.

Thanks for helping us out on this!

 

PCM Relay should "click" with Key on, that powers up the PCM(computer) and it turns on the CEL at that time, boot up

In cab fuse box check if fuse 19 has 12volts with key on, it should

There is a PCM Power diode in the engine fuse box, looks like a Fuse but has "-->|---" on it instead of a number
You can test it with an OHM Meter, should read 0 ohms BUT.......only one way, so reverse red and black probes if it doesn't show 0 ohms, if it doesn't show 0 ohms either way you need to replace it

 

You, my friend, are a rockstar!

Fuse hit 12 but settled in at 11.

I pulled the diode but couldn't get to zero. I'll put that on me for probably not doing it the right way. Putting the tips together got me to zero but my multi-meter sat at 1 when testing. I wiped the connector for the diode with my greasy fingers because it looked dirty. Stuck in back in and heard a couple of clicks. The truck started up right away and the OBD is working.

As an added bonus, my son now understands why I hate electrical... I had pulled those diodes out and put them back in previously. I guess I'll go ahead and see if I can find some to replace them all...

Many thanks!

 

Good work

Glad you got it going and thanks for the update, and THE FIX, it will help someone else down the road