jdeng

Member 1 16 posts Jess Davis Report post Posted April 9, 2015 Update on my ongoing torque converter locking/unlocking issue: My transmission croaked last winter, and I went with my mechanic's recommendation of a reman from Jasper. This has been working fine, as it should for $4000, except my intermittent locking/unlocking thing has continued. The last couple of times, cleaning the battery cables didn't help for very long. I did, at some point here, test the AC output of the alternator at .022 volts, with two different meters, and I had long ago tried pulling the alternator fuse, with no affect. A few weeks ago, I took the truck back to the mechanic for a minor leak at the dipstick tube (I think), and mentioned that the hunting thing again. He added a ground wire to the APP, which he said had helped the problem on a number of other trucks that he takes care of. I've been several weeks without a single lock/unlock incident. But now, I occasionally get a dead throttle pedal, and a fault code of P121 (APP signal not right). It always comes back with a couple of strokes of the pedal, and Lance says I should probably replace the APP. Am I right in my interpretation of the alternator AC voltage test that I do NOT have an alternator problem? Anyone have advice on replacing the APP? Anyone else ever put a ground on the APP?

I'll update my torque converter locking/unlocking status. Whenever mine was acting up, I would tighten the battery cables, and it would go away. I was using some marine batteries with 3/8 studs, and the usual stack of cables. I noticed that every time I checked, (basically whenever the lock/unlock thing flared up), I could tighten the nuts a little bit. The problem got some better when I added lockwashers, so maybe they were backing off, or maybe the springiness of the washer helped make the connection better. I also noticed that I was overtightening the nuts and very gradually pulling the studs up through the lead terminal. Anyway, this winter my 3-year-old, $60 Walmart marine department closeout batteries finally began to stagger, so I put in two new, appropriately-sized Interstate batteries with normal posts. My normal-battery-post tactic is to use the solid brass clamps with studs, and convert all the wires and cable to ring terminals (already done on the previous battery setup). So I realized today that I've gone several months now with no lock/unlock problems. I guess one other factor is moisture--there seemed to be some correlation between moisture and the problem (for me). Apparently, moisture is a thing of the past here in NW Oklahoma, so it's no longer a factor. But maybe it will rain next year, and I will have one more data point.

A couple of the manufacturers of construction equipment that I've worked for always installed an external diode in the wire between the alternator output and the battery. I've heard several stories as to why it's needed (or was needed back when they started doing it, when they used Prestolite alternators). One was that there was an path to ground somewhere in the alternator that would drain the battery. This was purported to be only on an occasional alternator, but it was cheaper to put the diode in all the time than it was to sort out the bad alternators. The other story was that if you didn't have it, you couldn't get the engine to shut off. I can't make any sense out of that one anymore, but at the time it was explained to me, it made some sort of sense. It's entirely possible that we were wiring things a little oddly--lots of confusion back at the point in history where solenoid shutoffs for diesels were new, and alternators were new, and everyone thought that a wiring harness with 10 wires was so unimaginably complex that we mortals would never be able to fully comprehend it.

I used to most of my farming at night, back when I was ambitious. I found that the **** Cepek Baja Lasers (discontinued, but still available on eBay) were a great value. I put 100-watt bulbs in them, slathered silicone all over the place to keep the dust at bay, rubber-mounted them, and they worked great. Put a big, bright spot out there about a quarter of a mile. I filled in all the other area with a pair of ABL trapezoid pattern lights (55 watt bulbs swapped for 100w), and replaced the 4 sealed-beams that were stock on the fenders with Deere Halogen replacements. Got a lot of questions from neighbors about that setup. The Baja Lasers with the sealing job lasted 4 or 5 years before the reflectors got dim. The chrome housings were pitted by then, also. Without the sealing, they were full of dust in a few weeks. Odd thing--I tried the 130 watt bulbs, one at a time, and could see absolutely no difference in the light output. They burned out pretty quickly, too. Big wires and good relays were a key part of the system also. The Baja Lasers looked just like the ones that KC used to sell, and just like the cheap ones that Walmart and O'Reilly sell.

Is it possible that some connection in the original ground wire(s) was bad, and that when the ground wires are all re-done and re-routed, it of course got fixed? And maybe the re-routing actually isn't what solved the problem? I was pretty sure that adding a ground wire to my alternator fixed mine, but I later realized that I had also cleaned and reworked all my battery terminals at the same time. Since then I've fixed it several times by retightening them. And if anyone has a good battery terminal system worked out, or even a thread where that is discussed and argued about, I'd like to know about it. I have my solutions, but am open to better ones. Not happy that I have to tighten mine every couple of months.

I'm confused, jag. Is this the ground wire that goes from the L battery to the R battery? Are you just adding an additional ground or re-routing the existing one?

I went to some trouble to evaluate LEDs versus halogens for a piece of equipment we are building. LEDs are getting there, but if you compare the actual light output per dollar, they are a long way off, still. I was looking at decent stuff but not extravagant like PIAA--ABL, Hella, Hobbs, Speaker, etc. Best bang/buck inmho is a well-designed halogen. Another 5 years or so, and LEDs will be there. Most of the manufacturers of lights are pushing LEDs real hard, and their catalogs and websites are deliberately misleading--most will give either no light output numbers, or use lumens for one type and something else for LED. They don't seem to want you to directly compare them.

Odd think I noticed on the Dodge wiring diagram is that the lights have power all the time, each through its own fuse, and the switch/relay provides the ground. Not sure why they did this, and it won't affect your plans to add more relays, really. Just kind of strange. Maybe it makes it easier for each light to have its own fuse, while the switch/relay only needs to make one ground for high, one for low. But let us knwo how your sport light conversion works out--my stock lights are terrible.

I bought a cheapo gauge from Glow Shift on ebay for less than $50. Looks good, seems accurate (it corresponded to the mechanical gauge I was checking with, fwiw), and the instructions were good. Downside is that the sending unit crapped out after about a year (and yes, it is remote-mounted off the engine). Upside is that you can get on their website and buy a replacement sender for $12. So I give them an A+ for service. I'll probably go ahead and buy a trans temp gauge from them. My experience with gauges in general is that most brands of pressure sending units tend to break occasionally, so I can't say that GlowShift is worse than other brands. And my experience with mechanical gauges is soured by my experience with cleaning the interior up from broken copper oil pressure line once. I do wish that I hadn't gone with the "tinted" gauge. It's a little hard to read in the daytime.

Somewhere I saw another formula for figuring inflation pressure that used the section height of the tire. Supposedly, a correctly inflated tire will have a loaded section height (rim to ground) of some percentage of its unloaded section height. And of course, I can't find that anymore. Ever heard of doing it that way?

I recommend NOT ignoring it when things start clattering in 4WD. Mine beat the little ball to pieces, and ruined the .50 pin that it runs on. NAPA rebuilt driveshaft on the way for $250. If I had caught it earlier, it would have been just the ball kit and seal--even the ujoints are fine.

I bought a cheapo gauge from Glow Shift on ebay for less than $50. Looks good, seems accurate (it corresponded to the mechanical gauge I was checking with, fwiw), and the instructions were good. Downside is that the sending unit crapped out after about a year (and yes, it is remote-mounted off the engine). Upside is that you can get on their website and buy a replacement sender for $12. So I give them an A+ for service. I'll probably go ahead and buy a trans temp gauge from them. I do wish that I hadn't gone with the "tinted" gauge. It's a little hard to read in the daytime.

Based on various comments above, and the wonderful picture of the internal circuitry of the VP44, here's what I think I understand: 1. There are 2 different parts of the fuel circuit before the actual high-pressure part: Lift Pump to Vane Pump, Vane Pump to High-pressure Pump. 2. There are 3 relief valves involved. Or pop-offs, bypasses, or whatever you want to call them. One is internal to the lift pump, and bypasses back to the suction side of the lift pump. This one determines what pressure the lift pump can create. Second is inside the VP44, located at the output side of the vane pump. It bypasses back to the inlet side of the vane pump. Third is the one at the return or outlet of the VP44, also working off of the output side of the vane pump, but it relieves to the return fitting and goes back to the tank. I've seen something that says the vane pump is putting out 250psi, and I've also seen 14.5 psi. No idea which is correct. 3. Nobody seems to be fretting about what the vane pump pressure is, nor figuring out how to put a gauge on it. Seems like this would be the thing to monitor, since it's what is actually feeding the high-pressure pump, and it has 2 relief valves that could die and cause problems. 4. Lift pump pressure is feeding the positive-displacement vane pump, and unless that vane pump is turning, there's no significant flow out the return fitting of the VP44. So lift pump pressure has almost nothing to do with cooling the VP44, despite what almost everyone says. In othe words, the actual fuel flow out the return of the VP44 is going to be the same with a lift pump pressure of 5psi or 20 psi. Maybe a clearer way to say it is this: At a certain engine rpm, Vane pump flow is constant. Part of that flow goes gets dumped back to the vane pump's own inlet, part goes out the injectors, and the rest out the return fitting. 5. I'm don't know why there are two relief valves on the vane pump circuit. I guess the one that goes back to the inlet is set at a lower pressure than the one on the VP44 outlet. Anyone know for sure? 6. DDOSSDD's comment about the check valve is very interesting. Assuming that all lift pumps are vane-type, when they crap out, the vane pump inside the VP44 can't suck fuel through them. If there was a check valve going around the lift pump, it might save the VP44. Are there some lift pumps that are turbine-style or diaphram-style? If so, you can probably suck fuel through those. The ones I've seen pictures of cut apart are all vane-style. Please correct me if I'm wrong on any of this.

I have an update on my converter lock/unlock problem. I thought I had fixed it once by adding a ground wire on the alternator, and maybe that did help, but I also cleaned and re-did the battery terminals at that time. I've now fixed it 3 or 4 times by tightening or cleaning the battery terminals. Last time, I did nothing except tighten the nuts on the terminal about a quarter of a turn each. Not saying that's the problem on everyone's truck, of course, but on mine, it's working. So the obvious thing to research now, for me, is better battery terminals.

OK, I have a brief update on my particular problems. Since pulling the alternator fuse didn't help, and washing the truck made it worse, when I finally got time to work on it, here what I did:1. Cleaned the battery terminals. They were already clean, but I re-configured them a little because I didn't like the way the shop had done them. I don't figure that I made any difference on my transmission problem.2. Loosened and retightend the alternator mounting bolts. At least the ones that were easy to get to. Thinks look kind of corroded and rusty there.3. Added a ground wire from the alternator case to the battery. I went to one of the case screws, since it was easy to get to.I now have 3 weeks of occasional driving and the lock/unlock problem is completely fixed. It's too dry here to do much farmwork, and I'm not feeding cattle, so the truck doesn't get driven much, but I think I've driven enough to consider the problem fixed.:hyper:I think it was the ground wire that did the trick. Does that make any sense to you guys who actually understand the system? If so, how is the alternator supposed to be grounded? Is it just through the mounting bolts?JKD