In this video I bring you along as I have a look at a customers Ram 3500 with the big hemi that was dropped off with the money light on. I took a look at it to discover it was missing power to the fuel tank pressure sensor. Now it is a matter of determining if it is the PCM or broken wire.
-Enjoy!
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Hey there, viewers and welcome back to the south main auto channel, we're outside in the 2016 hemi dodge ram. It's the 3500. It's got the money light on 44 420 miles um. I gave a quick look at this the other day for the fella, and it has a code for something to do with the evap, and i checked it out quick, like a bunny rabbit and it is missing the 5 volt uh reference or the 5 volt power Supply to the fuel tank pressure sensor, uh, which has already been replaced on top of the fuel tank, so we have to track that down at the moment that i checked it for him.

I just didn't have time. I had one other issue. We fixed that i don't remember what it was, but at any rate, so i've got some time today. We've got to find out.

Do we have a broken wire, or do we have a bad computer and that's what we need to know so now that we're all up to speed? That's what we're going to do, because i think the other day when he brought it in. I had a bad attitude and i was out of time if, i'm being perfectly honest, i might wait for the cars here so today. We're gon na have a better attitude and a little more time. So what we're gon na do you're gon na, have to believe me in the fact that we don't have five volts down there and we need to find a wiring diagram and we need to go right to the source.

We need to go right to the computer and find out do we have five volts there and then, if we do now, we've got to go on the hunt for the broken wire, we'll go in and see the very lovely misses, though don't worry. Miss though we'll get it, what oh wait we'll get it we'll get our own paper? Okay right! Thanks we're doing school work here, okay, yeah go away! So let's have a look see what we're after, let me get a pointing apparatus, switch hands pop the cap. So what do we have? We have the fuel tank pressure sensor here, standard three wire pressure: transducers. We have a ground, the signal wire and then the five volt wire, and that goes up to inline chassis engine transmission.

That's handy thanks for not putting a number. There chrysler and then from there it goes to the pcm, and i think this is where i got frustrated last time and just ran out of time because they didn't give me a connector number. So, like you know where, where is this uh? So that's what we got to try to spend some time uh looking because, ideally i know for a fact that uh when i had it over there on josh's, lift i checked here and i had no five volts, but with it unplugged. I had five volts on the signal wire and then i had a good ground.

So that's you know this wire is good. This wire is good. This wire is sus and uh. We should have five volts.

Error would have been nice if i quickly could have found this open it up and say: do i have five volts here and then nothing here you know is the connector crappy uh, but i think what we'll do is we'll see if we can find where the Pcm lives, if that's easy to get to and we can find a connector c1 and pin 48. We can quickly check to see if we have five volts there and if we do then good, then we know for a fact: we have a broken wire and then it just becomes the hunt. So i pop the hood on her and i believe that this is the pcm hiding over here. I don't know which one is c2, but it's a 50 50 chance.
I do know that um. I think this is still our best option, because that is easy to get to now. I do recall looking underneath it right here behind the driver's side. Fender well, we'll take a look.

There was a couple of inline connectors there. So there's a connector there and one there and that's not mud, that's a farm truck. So if you can want to take a guess what that is, so i don't know if those are the connectors they're talking about. I thought i took a quick glance at them and did not see uh at whatever pin number it was, which was yeah, pin one and two and three.

I think i remember looking at it not seeing any of those wire colors near you know the edge of the connectors where one two and three would be so. I might have to do a little research on that. But let's perhaps start here so we'll take a guess on who is number two? It's this one or it's this one. We won't cut the zip tie until we find out, let's see if we can find some identifiers.

So there is a number on top of that. I believe that is 36. and that's 24. i'll figure this out folks who's, who here i might have to get out my old man glasses indoors, my little magnifying glass here.

So we can read the numbers and we'll find out which pin houses our 5 volt wire. Potentially, i think we might be a couple of lucky sons and mothers here today, because if that is a 24 because i think that's it, 96 24, 48, yeah, 48 and 48 would be 96. So that would make sense. So if that's 24 we're looking for pin 48 boom some days, you get lucky fella, because that 24 plus 24 is 48.

So that should be the second row right here on top and that looks like it's dark blue. That looks like dark blue with purple or dark blue pink. What's this one according to magnifying glass, this one 24 48 is black is white, so it has to be because i think we're looking for a blue wire and we are dark blue with pink 18 gauge. 48, look at that.

It is right. On top boy, i tell you what today is going to be a good day. Today's gon na be a good day folks, so we're gon na take and click this one back together, because we don't have no business being over. Here, uh, maybe why you got ta, be like that: okay, okay, that one's clicked back together! This is the wire we're after so happened to be right in a good spot.

So we'll stick our little screwdriver there right behind it, because that's where we're going we'll get a back probe, then we'll get a meter and we'll turn the key on and we'll see if we have five volts. Okay, the key is on sorry about my creaky stool. Here it's one of them: el cheapos, from the harbor freight, so it's a little noisy, but the truck's a little tall. Okay! So here's our meter we're gon na find the ground.
Maybe the pcm is grounded. I don't know we need to find something to verify that uh. Let me check, let me ground it to something else: everything's freaking plastic on nowadays cars. It's kind of annoying there's like nothing metal to hook to let me hook to the alternator case here, where you can't see all right and then we're gon na go we're gon na go to graphing meter we're gon na oops.

Here i am getting all clicky, i'm back out of there we're going to go to volts dc. We've got around a 20 volt scale, we're going to test our meter. I got it hooked to that. This was battery positive.

This is battery positive. Maybe it's not battery positive. This one should be positive. Okay, there we go 12.36, so we know our meter works.

So that's good and then we'll reach up here in the old hat, we'll grab us a t-pin. We'll come right in on that little guy, nice and straight make sure i think we're in all the way clip onto that bada bing bada boom. Look at that fellas four point: nine or niner. So we do have five volts here, but we don't have five volts down there uh.

So what kind of problems can you have with a wire? I think there's only three that you can have. You can have a short, you can have an open or you can have high resistance, and that is it. Those are the only problems you can have with a wire, a physical wire, so we're talking about the wire itself, we're not talking about a computer, sending corrupt data down it or anything like that. We're talking about the physical wire and the condition it can be in a short and open or high resistance.

That's the only types of wire problems you can have, regardless of what somebody else tells you so a short that will include a short to power, a short to ground or short to another circuit and open, is an open. That's wires, cut or high resistance, and that is it. Those are the only wiring problems you can ever have in your entire life. Every type of wiring problem will fall in one of those two categories, so this one here i believe we clearly have an open circuit, because if we had a short, we would probably have five volt reference codes and we probably would be seeing zero volts here, um.

So, let's uh, let's get after it boys, that's all we can do. We know what we have here uh. I should be smart about this because the vehicle has been gone and has returned to my shop. We should be smart about it and make sure that the problem still exists, which i assume it does, because the money light was still on.

So, let's plug a scan tool in let's look at our fuel tank pressure data pin and if it is still abnormal, then we know we're still missing 5 volts down there, and then i say our next step is to find this in-line chassis engine transmission. We need to find this connector because that's going to be the next easiest thing, i think i will also while i'm right here, quick, like a bunny, i'm just going to see where this harness goes looks like it comes over here, runs across the engine looks like It's got some pretty heavy rub spots on it, i'm just going to do a visual inspection without putting my mitts on it too heavily and see if we can find out where it goes and also help us make an assessment here. So that's the plan stan. So in the live data here we see it's still broke so fuel tank pressure is at 14.12 inches of the water, which is about a half a psi which we know is that's too much and it has a code stored in it for uh something to do With the purge purge system performance because it's turning the purge valve on, but it's not seeing any change in that fuel tank pressure because it doesn't have five volts going to it.
So the sensor, just you know, at zero i'll try not to give you a vertigo, but here is the fuel tank she's a big one, and up above the fuel tank lives, the fuel tank pressure sensor, which i'm not even gon na try to to get at. For you, folks um, i think you can see a little bit of it sticking out there, but then the harness to it runs up here through the frame. Rail runs down the driver's side frame, rail and then heads into the forward direction. Now, like i say, i did see these connectors here, which i don't believe are it because i did look around them last time i was in, and i didn't see our wire color that we needed uh and you can see she's a little crappy, we'll say, and We do have this inline chassis connector, which i'm going to take.

I'm going to do the hokey pokey up here, move some of the dirt and see if we see a connector and if we don't we're just going to have to take a guess somewhere to start splitting the system down and see what uh, what we can figure Out because it's a tad cruddy, but i don't know if there's a connector under that crud, i like calling it crud, it makes me feel better. So we'll get this set up and let's do the hokey pokey and i'm gon na. Do the hokey pokey without you, because i don't want to hold the camera and get crud all around on everything, minimal, crud removal, and i think we might be on to something because look i think i see some bigger wires might be nothing. But i wanted to bring it along just in case.

Oh, is that a blue instead of blue and a pink there on the bottom is my look still strong with me. It can't be this easy. It can't be the first place we cleaned off the crud and hence enhance unenhanced. I can't tell because my face is too close to the viewfinder.

My eyes are too old, but that definitely looks like a suspect spot. Let's uh get the screwdriver here, we'll dig out some more of this stuff. Oh yeah, there's something see. Oops people are asking me how come i'm not using a pressure washer once because i don't want to be working in the mud.
I'd rather work in dry cow crud than a wet cow crud. You know what i'm saying and don't don't be pissed at this guy for not cleaning it man, this guy's, a farmer. You should thank him otherwise, you'll starve to death. Okay, folks, guys like this, keep the world running huge baby.

I think we have some room now, folks, i wanted to get things cleaned off, because i think we're about to get the money shot. Let's come over here and find us a hooker boom got one. I'm thinking, let me see if i get everybody up in here uh, let's see, i think it's this bottom wire. Oh, yes, ma'am! Are you guys ready? Oh, this is a tuffy she's broke right yeah.

She broke your stretchy little fella ain't ya come on. Here comes the money shot pink here we are baby, we found it first try. This is all. What are you doing same thing? I need to get out the bible all right.

You know how they're spiritual gifts is one of them finding wires by any chance. Is that my spiritual gift yeah, i don't know that's listed, but it probably is a gift from the lord. I know because guess what i just did, i don't mean another wire and you can't even smell yet yeah this one down here sniffer come in here to brag. That's all! Congratulations! Thanks! Yeah! I don't know what it is folks, but i do have this uncanny ability to find broken wires.

It's almost odd, as it is almost like divine intervention um, but yeah. Now i mean that that is our wire right before we get all bragging about stuff um. I believe i did see that that was blue and pink. Of course, the drive shifts kind of in our way here.

I think we also have to see if that is the only wire that is abraded, because it appears because of the crud that is sitting on the crossmember, that it was doing. The old rub job on this thing and obviously it abraded through his abrasion. As the do you use the word braid it abraded in an abrasion-like fashion, uh through the harness here uh, which appeared to have tessa tape on it, which is some pretty rugged stuff um. But if that's happening man, that's gon na be a problem on this truck because there's a lot of crud underneath all of the harnesses.

So this could be a problem uh at any rate, i'm gon na take and work at this a little bit we're gon na unhook it off. Of that there we go now. We can probably see our wire color i'd. Have you guys on a tripod but there's kind of an awkward spot? Let's see here, let's get the wire where's our hook.

This is where right yeah. I just want to make sure it is the right wire, because that would stink to fix a wire and still have the same problem. Let me stick the hook down here, where i'm not going to get stuck, and it appears to be blue with pink, hooray hooray. We found the broken wire hoorah, let's get this fixed and i don't can't really think of anything else better to do maybe wrap a piece of radiator hose around it slit a piece of radiator hose wrap it around it, but i'm gon na before i get these Two twisted up make sure nothing else is kind of halfway gone through before we clean this off and then seal it up permanently.
I soldered in a new piece. Why? Because i like pissing off everybody on the internet uh, so i had to put a little extension. So i just put a piece of 18 gauge blue in there soldered and heat shrink and sealed it there and also there, and i didn't see any other wires in the harness that were abraded. So i think we're in good shape there.

Uh. Let's go have a little look-see, though we'll go back to our live data and see if we've fixed it that'll, be the real truth: we'll go fuel and then tank pressure, bada bing, bada boom. We got her fixed, huh, lucky guess, baby lucky guess so now what has to be done is i have to kind of clean this up here a little bit and get to a good spot, because we've got to try to prevent this from happening again. Ultimately, it's happened because of the crud uh under there abrading its way through the harness so like.

I do want to clean this up a bit, get it taped back up and i'll, probably take like a piece of scrap radiator hose, maybe slit it stick it over. It and then kind of reattach everything and then just hope for the best, and just as you thought you were getting caught up, another one gets dragged in scotch super 88 brand spanking new roll best part about this. You ready ah get a whiff of that. There ain't nothing like the smell of a brand new roll of scotch 88, not a sponsor.

The only downside is she's huge and we need to get in a tight area, a free tip friday, for you, i've showed this many times. Take your classic quarter. Inch drive, this is the 8 mil variety try to pick one that doesn't have a big step in it and if you need to make what i call a mini roll, we'll get it peeled back here, we'll get it started boom get her started. You stick around the classic nine mil, not the eight mil, and then you just wind her around town, just bring her around like that.

Don't pull it tight, though folks. Just, however, many wraps, you think you'll need to make your mini roll and then put a couple extra and then leave her hanging, bring out your edc gerber there we go give her one of these right onto the floor, almost cut my finger and there you go. There's your mini roll of black tape. So i'm thinking i've got this piece of here.

Oh it's just a standard piece of your 5 8 heater hose. It looks like we're going to slit it down. This side touch your buddy, not your body. They say so there's that, and i think we'll be better served to open this up.

Uh, stick it on a harness couple, zip ties and that'll keep it from rubbing through is my thoughts. Hey girl, i've gone ahead. You guys seen that i made the soldering repair uh to get everybody upset, and then i made the mini roll mini roll. We taped it up, and then i made a mini roll of tessa tape.
The abrasion proof tape and put that over top of it also trying to give it the benefit of the doubt, and then i think we'll go like this with our hose. We should be able to slip that baby on there, i'm thinking. Oh, we got to gear up a little bit higher because i want to be able to still utilize that one factory zip tie that we can click her back in. I don't know if it's going to help it, but it sure ain't going to hurt it right.

All right, we all agree, slide that back down and then, like i say, i think, we'll throw a few zip ties on it. It has one factory retainer up here. Has another factory retainer here now the one that went here i did have to cut off. There was no reusing that it was a zip tie and uh.

I think that'll be good and i think that abrades abraded, because the transmission's always you know, he's hammering on that hemi and constantly just scuffing this wire a little bit back and forth. So perhaps some of the ones up on the frame that aren't attached to a moving part such as a transmission, might be okay other than a normal jiggly wigglies that gets going down the road. So, let's zip tie this up, make it look all fancy and then i think we're done we'll go eat. Some lunch whoa come up here with the snap on flush cuts.

They cut zip ties flush, so the next guy doesn't look like he got in a fight with a razor blade when he reaches his hand up here and there. I think that will resolve the rubbing issues. It does look like it's hold it up off that cross. Member then, of course, you know where it runs straight through here now i stuck it back in those factory holders.

So again, folks, before you get on this guy about not washing this truck just lay off it a little bit. A lot of farmers have bigger problems than washing off their bottom of their trunk before it comes to the mechanic. So that's that folks, uh show's over this was just a simple, routine, broken wire chasing the wire down. Checking it on this end checking it on the other end.

Of course, i didn't show you checking on the other end, because you had to believe me because we're starting to have a little bit of trust, you and i and uh, and then just using our schnoz and our spiritual gifts. If you will to go through and find the broken wire which, for some reason we have an uncanny ability to do, and we did we came, we saw we conquered and uh just remember folks if you got food on your table or in your grocery store. Thank a farmer, okay, don't forget it and uh you're, not forgetting that. Don't forget to go in the comment sections! The questions, the comments, the instinct, the facebook.

You all know this by now y'all, i just said y'all, but i'm from new york and just for my viewers. If i can do it, you can do it thanks for watching.

By EricO

14 thoughts on “Ram 3500 cab chassi: the hunt for the broken wire”
  1. Avataaar/Circle Created with python_avatars MoutainMan3000 says:

    That small socket tape roll trick is probably the best trick I've learned off YouTube

  2. Avataaar/Circle Created with python_avatars Jay Strock says:

    You are a Napa auto care center and they do not sponser you?!

  3. Avataaar/Circle Created with python_avatars Dave Dodge says:

    So much fun working on the ranch vehicles with "Shtuff" covering the whole undercarriage. At least it wasn't fresh "shtuff"

  4. Avataaar/Circle Created with python_avatars Joey The Dime says:

    SMA on a Friday afternoon!!

  5. Avataaar/Circle Created with python_avatars MoutainMan3000 says:

    Nothing like some aerosolized "crud" to liven up your day…

  6. Avataaar/Circle Created with python_avatars Shadetree tech says:

    When i look at a new york video i expect to see snow.

  7. Avataaar/Circle Created with python_avatars Thomas H says:

    I love a good hunt.
    Hey Eric, how did your deer hunting season go?
    Any Backstraps?

  8. Avataaar/Circle Created with python_avatars Marcin Wojciechowski says:

    Me like hunting videos xD

  9. Avataaar/Circle Created with python_avatars old biker says:

    the hunt for the red wire October

  10. Avataaar/Circle Created with python_avatars Mark Nease says:

    Would be a good vehicle for the Motor City Mechanic being that he enjoys working on MOPARS.

  11. Avataaar/Circle Created with python_avatars Greg M says:

    Nothing like a good hunt!

  12. Avataaar/Circle Created with python_avatars Flatnose says:

    SMA! Gonna be a good day.

  13. Avataaar/Circle Created with python_avatars Jonathan Tolbert says:

    The hunt for red October!

  14. Avataaar/Circle Created with python_avatars MoutainMan3000 says:

    I love these hunts for broken wires. Gives me hope I'll be able to find the mystery electrical issues I get.

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