7.3l wont start need to check the wiring harness dont know how to go about checking which wires are faulty. I have read the forums on what to do but frankly i dont understand exactly whats being said.

 

No problem not understanding. It can be confusing at first.

Let's start with the basics. Do you have a multi meter than can read ohms? Do you know how to check ohms with the meter?

Go to the post you have a question about and right click on the word permalink at the top of the box. Click copy link location and post that here in this thread. We can explain step by step exactly what to do.

 

i do have a multimeter and i thought i knew how to use it however not sure the exact process when checking the IDM female end connector. Not sure exactly where to put both probes.

 

This may help. (see attached).

The IDM can be found inside the inner fender (behind the F-250/350/450/550 badge). Removing the inner fender liner permits access.

 

thanks, would pin 23 and pin 24 be where i put the ground (black) probe and then red probe in each of the other 8 to pull the correct resistance? im inept sorry.

 

You are measuring resistance so the color of the probe doesn't really matter. The way you are suggesting will work fine. Pin 23 is the power feed to the left bank and Pin 24 is the power feed to the right bank.

One thing that isn't mentioned in the article but should be checked is the IDM ground. While still in the ohm setting, place one probe on pin 26 and the other on the negative battery post. You want to see a fairly low number...I don't remember what it was when I checked but I think it was less then 1 ohm...

 

if the resistance for all the pins meets the requirement would that mean the IDM then would be at fault?

 

No. It just means your wiring from the IDM to the injectors is fine. Also means the injector solenoids appear to be in range as well. It's recommended to test the wiring before installing a new IDM because there may be a fault in the wiring that caused the original IDM to fail....if so, then your new unit will be damaged as well.

You didn't post any additional information regarding symptoms or what is leading you to mess with the IDM so I have no clue if it's bad or not. It's not very common for an IDM to fail but it does happen from time to time. They also sometimes fill with water....not sure how that happens but it's been seen a few times.

 

yah im sorry i have a few posts going, i have run through a whole mess of diagnostics to narrow it down to either the harness or the IDM/PCM. My IDM was bubbling and corroded on the sides i even thought when i pulled it that it looked like water damage. I was pulling both 1293 and 1294 codes.

 

ok i got zero OHMS from every port on the IDM connector except for cylinder number 4 which was around 350......i have got to be doing something wrong.

 

If your multimeter doesn't read low resistance, it could show a really low number, like 0.1. What is the make/model of your multimeter?

4 is a problem. Double-check everything.

 

Yes that's correct. Just remember that pin 23 in that link is for the driver side, so when you place the black lead there, touch the red lead to the driver side pins (22, 7, 19, 9) and do the others against pin 24 when you switch sides.

First make sure your meter is set to read ohms. Google electrical ohm symbol since I don't know how to type it in here. Kind of looks like an upside down overshoe with feet on it.

After you've got the selector pointing to that, touch the red and black lead together and see if the meter reads 0. (it's supposed to if things are working right.) Then place the black lead on the negative post (black cable) on your driver side battery and place the red lead on one of the 3 mounting bolts to the alternator. See if you get a reading of 0 or close to it again. (hopefully yes). If so, repeat the IDM test. If not, there's an issue with the meter or setting.

 

Here it is, omega: Ω