MADMODDER
10+ Year Member
⭐Supporting Member
ASE Certified Tech
TRS 20th Anniversary
U.S. Military - Veteran
- Joined
- Sep 29, 2015
- Messages
- 116
- Points
- 1,601
- City
- Kennesaw
- State - Country
- GA - USA
- Vehicle Year
- 2010
- Vehicle
- Ford Ranger
- Drive
- 4WD
- Engine
- 4.0L
- Transmission
- Manual
Good afternoon. This is a story to be heard and a warning heeded.
For those not in the know, I'm a euro tech. I recently got an apprentice, who recently bought a '95 Ranger. The other day it quit on him. I thought I'd let him use this opportunity to learn some hard lessons. I, somewhat, showed him how to navigate alldata. Explained how the system works and made sure he didn't do anymore damage. We scanned the truck and came up with P0232. We found the fuel pump fuse was blown. Somebody had put a 30amp fuse there and its suppose to be 20. So we put a 20 and it popped. Replaced it again and did a quick google. multiple sources said the fuel pump is the most likely culprit. He asked if we should replace it and I told him, "it is the mostly culprit so you can either shotgun a fuel pump or confirm with diag."
He chose to shot gun because he needs transport. As we all do.
So we ordered a fuel pump and upon removing the bed, we found the fuel pump harness was smashed between the tank and the frame. Seeing that, we thought "surely there is a short there." but we already have a new fuel pump so what the hell. Replaced the pump, ohm'd out the harness and it met spec. So we thought, "maybe the short was in the pump" and with that replaced, we tried to start again.
The fuse blew again.
So we printed off the electrical diagram and went to town. I figured I use this chance to exercise my electrical skill because I don't get to often and teach my apprentice a few things. Mainly I=E/R but also what each of those things are and their relation to each other.
With key off, we confirmed the fuse has 12v as well as lead 3 at the pump relay.
lead 1 has .9ohms.
lead 2 has 2.1ohms
lead 5 has 3.8ohms
with key on, we confirmed lead 3 still has 12v.
lead 1 has 12v
lead 2 has 12v
lead 5 had 12v for a 1-2 seconds then 13ohms.
Seemed odd, it should had 6-8V.
We tested the relay, it is good.
So we checked grounds, those are not great, not terrible. It is 31 years old. Thing 1, 2 and 3 have been in there. But 1 thing at a time.
Checked the inertia fuel shut-off (IFS) its good.
Checked the wire from the lead 5 to the IFS, its good.
Check the wire from the IFS to the fuel pump, its good.
Checked continuity between the fuel pump relay and the PCM. They are good.
So what are we missing?
The PCM itself. There is no clear test for it you would need to map out the pins and figure it out the long way around.
Or you could remove the PCM and open it, which is what I did.
Upon opening, we found a section is fried.
Next time, he will spend 5mins to remove the PCM and make sure it isn't fried before replacing the fuel pump.
As stated, I'm a euro tech and not very familiar with Fords. So if I am missing somethings, please let me know. Likewise, if you have info to add that could help somebody in the future, it would be much appreciated.
For those not in the know, I'm a euro tech. I recently got an apprentice, who recently bought a '95 Ranger. The other day it quit on him. I thought I'd let him use this opportunity to learn some hard lessons. I, somewhat, showed him how to navigate alldata. Explained how the system works and made sure he didn't do anymore damage. We scanned the truck and came up with P0232. We found the fuel pump fuse was blown. Somebody had put a 30amp fuse there and its suppose to be 20. So we put a 20 and it popped. Replaced it again and did a quick google. multiple sources said the fuel pump is the most likely culprit. He asked if we should replace it and I told him, "it is the mostly culprit so you can either shotgun a fuel pump or confirm with diag."
He chose to shot gun because he needs transport. As we all do.
So we ordered a fuel pump and upon removing the bed, we found the fuel pump harness was smashed between the tank and the frame. Seeing that, we thought "surely there is a short there." but we already have a new fuel pump so what the hell. Replaced the pump, ohm'd out the harness and it met spec. So we thought, "maybe the short was in the pump" and with that replaced, we tried to start again.
The fuse blew again.
So we printed off the electrical diagram and went to town. I figured I use this chance to exercise my electrical skill because I don't get to often and teach my apprentice a few things. Mainly I=E/R but also what each of those things are and their relation to each other.
With key off, we confirmed the fuse has 12v as well as lead 3 at the pump relay.
lead 1 has .9ohms.
lead 2 has 2.1ohms
lead 5 has 3.8ohms
with key on, we confirmed lead 3 still has 12v.
lead 1 has 12v
lead 2 has 12v
lead 5 had 12v for a 1-2 seconds then 13ohms.
Seemed odd, it should had 6-8V.
We tested the relay, it is good.
So we checked grounds, those are not great, not terrible. It is 31 years old. Thing 1, 2 and 3 have been in there. But 1 thing at a time.
Checked the inertia fuel shut-off (IFS) its good.
Checked the wire from the lead 5 to the IFS, its good.
Check the wire from the IFS to the fuel pump, its good.
Checked continuity between the fuel pump relay and the PCM. They are good.
So what are we missing?
The PCM itself. There is no clear test for it you would need to map out the pins and figure it out the long way around.
Or you could remove the PCM and open it, which is what I did.
Upon opening, we found a section is fried.
Next time, he will spend 5mins to remove the PCM and make sure it isn't fried before replacing the fuel pump.
As stated, I'm a euro tech and not very familiar with Fords. So if I am missing somethings, please let me know. Likewise, if you have info to add that could help somebody in the future, it would be much appreciated.
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