No start after battery crossover, NEED HELP!!

[Dillonw127]

Alrighty guys I’m going crazy trying to figure this out. Long story short while we were out in the truck, 1996 Ford Ranger 4.0, my dual battery box that I have in the bed slid forward and the battery grounded out on the bed itself. The truck stalled out and everything shut off besides the little red battery light on the dash. I initially checked all fuses inside the cab and under the hood, nothing was blown. It wasn’t until I replaced the starter solenoid that I could get power to at least the starter and most of the electronics like headlights, radio, exc. The truck will still not start, when I turn the key the only thing that happens is the motor turns. I have no power to fuel pump, I have no spark, and I’m pretty sure the pcm has no power because when I turn the key to auxiliary the check engine light doesn’t come on. I’m stuck, any help or guidance would be greatly appreciated.

 

[black_demon69]

I would see if you have communication to a code scanner.. if not probably bad ECU/ECM would be my guess

 

[Dillonw127]

I would see if you have communication to a code scanner.. if not probably bad ECU/ECM would be my guess

If it doesn’t have communication, what would that look like on the scanner? Just a blank screen or would it give an error message typically?

 

[Blmpkn]

If it doesn’t have communication, what would that look like on the scanner? Just a blank screen or would it give an error message typically?

Probably depends on the scanner, either way.. you'd know.

 

[lil_Blue_Ford]

wonder if some relays could have got fried. My first thought was the main fuse got toasted, but if you have partial power then it may not be. I’d probably test/pull and test all fuses and relays, I’ve seen fuses that visually look fine but don’t work. Not common, most fail as designed and are visually noticeable, but not always. Check the fuel pump inertia switch too.

 

[Dillonw127]

wonder if some relays could have got fried. My first thought was the main fuse got toasted, but if you have partial power then it may not be. I’d probably test/pull and test all fuses and relays, I’ve seen fuses that visually look fine but don’t work. Not common, most fail as designed and are visually noticeable, but not always. Check the fuel pump inertia switch too.

I was kinda leaning towards the relays also, looking at them they look fine but I guess you never no really till you swap them out, I have some oe replacement relays coming in today to see if it makes a difference.

 

[Dillonw127]

I was kinda leaning towards the relays also, looking at them they look fine but I guess you never no really till you swap them out, I have some oe replacement relays coming in today to see if it makes a difference.

I checked the inertia switch as well and it seemed fine, red button was already pressed down which I believe means it wasn’t tripped.

 

[RonD]

The No CEL(check engine light) is the big thing at this point, no CEL = no spark and no fuel

Check fuse #19 in the cab fuse box, 25amp, should have 12volts with key on
Use a test light or volt meter to test for 12volts at these fuses, fuse maybe OK but no 12volts
Pull out the fuse and test the two connections for that fuse, ONE will have 12volts, may need Key on

Check fuse #13 in ENGINE fuse box, 30amp, should have 12volts all the time
In the engine fuse box is also the PCM relay, it supplies 12volt to computer(PCM) with key on

When you turn on the key 12v from cab fuse 19 goes to engine fuse box and closes PCM relay
PCM relay then passes fuse 13 12volts to the Computer(PCM) and other engine systems
When PCM powers up it Grounds CEL bulb and it lights up
It also actives fuel pump for 2 seconds

You can swap out the PCM relay with another relay in the engine fuse box, not Fuel pump relay, lol

Fuse 11 in cab fuse box powers CEL, so you can check that fuse just in case, but engine would start if that fuse was blown

You need to solve the No CEL as the first step
It could be the computer was damaged
You can pull off the 104 wire connector and test for 12volts at the power wires on the connector
Pins 71 and 97, red wires, are the 2 main 12volt wires that power computer, they come from PCM relay
If these wires have 12v with key on but still no CEL then computer is damaged

You can get 1996 Ranger owners manual from here: https://www.ranger-forums.com/gener...d-ranger-owner-manuals-1996-2011-models-3747/
If has fuse and relay layouts/maps