So my 96 ranger died while I was driving. I thought it was the fuel pump but later found it was fuse 19 which was blown. The fuse runs runs to the pcm relay's coil and also goes to the ignition coils..

so after i realized the fuse was blown, i replaced it and the truck started and blew the fuse again after a few seconds.

I was checking for shorts in the pcm relay and ignition coil wires and gave it 1 more try with a new fuse in and it ran fine.

I am scared to go for a drive and have the truck fail on the road again.

any ideas or anything i should check? Can a faulty ignition coil blow this fuse?

 

Well in case anybody is searching for a solution to the exact same problem. I eventually started throwing a CEL which indicated a faulty ignition coil.

 

Unfortunatly the same thing happened 2 me.19 blew then i put a new one in started up ran for 2 days then it blew again.put a new one in drove around the corner and it blew again. so i put in a new one and it blew right as i cranked it...i probobly blew 5 fuses trying it... i took everything apart and thought it was my pats moduel,when i put evrything back in it would start after i played with the pats everytime..2 days later.it blew again..i opened the fuse panne put anoher one in it started but if i touched the fuse it blew..i thought it was a short in the use block itself...untill i relized if i pulled out the fuse to the right of 19 tried cranking it put the fuse back in it starts and runs fine....now it dies and blow when i give it gas in reverse wtf!!! idk what to do anymore...

 

What engine?

 

v6 4.0

 

check the ground located on the firewall behind your ignition coil mine rubbed a hole in the wire right behind the plug!

 

HELP....so last week my truck died while i was driving it. I coasted to the shoulder and spent 3 hours going throuth the electrical system trying to figure out why everytime i replace the #19 fuse (pcm system/ignition coil) it instantly blows. I ended up changing the electronic ignition switch and replaced the fuse and it ran fine....until yesterday it died again...now I'm stumped...brand new ignition coil, ignition switch, spark plugs and wires, also brand new fuel pump...

 

Welcome to the forum

#19 in cab fuse box does power the ignition coil directly, but only powers the PCM relay's coil, .5amp, not PCM or other components, and it power it thru the Power Diode(see below)

It also powers the transceiver in the steering column, the "ring" around the key slot, its a 4 wire connector at the base of the column, red/light green stripe wire may be shorted which could blow #19

In the engine fuse box is the Power Diode for for #19, drawing here: https://www.justanswer.com/uploads/a...12407_bat1.gif

V34, above C101

These rarely fail, but can, pull it out and have a look for signs of overheating

 

According to my diagram, the #19 is a 20amp yellow fuse and it powers the ignition coil and pcm system

 

I think i understand what you're saying...ok I'll check under the column. I've got it pulled out already anyway.

 

Its a bit misleading, it doesn't power the PCM system just turns on the PCM Relay when fuse #19 is powered up
PCM relay has a separate fuse that powers PCM, injectors, and other engine systems


Transceiver looks like this: https://i.ebayimg.com/images/g/35cAA...M4m/s-l300.jpg

Its mounted on the key cylinder and the 4 wires run down the column and plug in to the vehicles harness
The connector can be green, white or grey

 

So...my tranceiver looks ok, there's no bad wires or anything that looks wrong there, it cranked last time no problem when i changed out the ignition switch, but i can't afford to change the ignition switch every week...could the pcm relay be blowing the fuse or shorting out the ignition switch? I'm horrible at wiring issues...not very good at this lol

 

PCM relay and Diode are working properly. Still clueless as to why my truck keeps popping this fuse...now instead of popping it instantly when i put a new fuse in, it pops when i turn the key over.

 

Then I would do this

Unplug the Coil pack
Use an OHM Meter to test the Red wire to Ground(engine metal), it of course should not show 0 or low OHMs

Leave it unplugged and turn on the key, or "key over", see if fuse blows, the coil pack is the biggest amp draw, it runs at .8-1.5 OHMs, which is almost a dead short

If fuse blows it could be Red wire has a short, but ohm meter should have shown that

But pull out the Power Diode, and repeat turning on the key, see if fuse blows, if so all thats left is the Transceiver, unplug it and repeat test by turning on the key

Those are the only 3 devises on that fuse
Coil pack
Power diode
Transceiver

 

I'll try that today. This helps a lot. I bought a bad *** multimeter yesterday and tested the relay switch and diode and they're good. Was gonna test the ignition coil, but couldn't figure out how. Thanks.

 

Does this look right to any body

 

NO, unplug it!!!

Read here: https://www.ranger-forums.com/ranger...ground-160461/

 

Replace the PCM diode. No CEL with KOEO on the early obd2 ranger? Crank no start? No Fuel pressure, no spark at the same time? The PCM is protecting itself and your engine by not completing a faulty circuit ( a failed diode in this example). The power diodes are paired with the relays to prevent any reverse current when the relay de-energizes and the tiny magnetic field it made collapses. There is more to it but that's the gist . Sometimes a person will put a higher rated fuse in 19 to keep it from blowing. That's never a good answer.

Takes about 5 minutes to swap the diode if you have no idea what you are doing, about a minute if you do.