greg g Posted September 22, 2015 Report Share Posted September 22, 2015 The regulator should be grounded by its mounting screws. Do you have a test light. it should light when powered and connected to one or both of the screws. 1 Quote Link to comment Share on other sites More sharing options...
HanksB3B Posted September 22, 2015 Report Share Posted September 22, 2015 For what it's worth: I had a similar problem but thought that my 5 year old Optima 6 Volt battery needed to be replaced. I removed a "suspect" quick disconnect battery terminal lead and installed two new solid brass terminals. I and was sure to wire battery brush both the battery terminals and new terminals. The difference in starting up was truly amazing. And yes I also have a ground strap from the engine block to the frame. Hank 1 Quote Link to comment Share on other sites More sharing options...
Ulu Posted September 22, 2015 Report Share Posted September 22, 2015 I just had the generator rebuilt. It was doing this before the generator rebuild, which was one of the reason i had the generator rebuilt....grrr, yep I'm going to work on the grounding Is it possible one of the new brushes is tight and sticking? I doubt that's the case, but I remember in the '70s, a friend who returned no fewer than 5 "rebuilt" starters to Kragen, because they would only work sporadically. Don't know what the trouble was, but it was a real ordeal for him. 1 Quote Link to comment Share on other sites More sharing options...
DollyDodge Posted September 22, 2015 Author Report Share Posted September 22, 2015 Where is a good spot to locate the ground strap from the engine to the frame? Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted September 22, 2015 Report Share Posted September 22, 2015 Not sure about the need for extra ground straps......especially since you have a fresh engine and were apart recently. I have my ground cable from the battery to the top of the transmission cover. Never had any ground issues anywhere on the truck. I can see this happening on one that has sat undisturbed for a long time with lots of corrosion but you should have good clean mechanical connections. I think it is far more likely that you have either a loose wire connection or a bad terminal ...at maybe the ammeter? Hth. Jeff 1 Quote Link to comment Share on other sites More sharing options...
DollyDodge Posted September 22, 2015 Author Report Share Posted September 22, 2015 My VR is from Roberts (I think, or maybe I got it from VPW, I forget). I replaced the old Autolite when all this trouble started-I followed the help I got on this forum and it looked like the VR was the problem. Here is the history: after I got the truck all back together every thing was fine except the charging. I replaced the VR, then had the generator checked at a local shop, they said it was fine. I then decided to have both the Generator and Starter (started died on me) rebuilt and VPW. Once they came back and I reinstalled them, the problem of not charging still existed. So that is where we are right now. Quote Link to comment Share on other sites More sharing options...
Merle Coggins Posted September 22, 2015 Report Share Posted September 22, 2015 Can you verify your generator and regulator connections? I don't mean this to be insulting, but I recently had this same thing happen to one other guy. Turns out that he had his Field wire going to the generator case as a ground, and not to the Field terminal. On the regulator there are 3 terminals; B or BAT should be connected to a wire that is coming from your Ammeter. The other side of the ammeter should go to the starter post, with the battery cable. A or ARM should be connected to the larger terminal of the generator. This is the Armature connection F or FLD should be connected to the smaller terminal of the generator. This is the Field coil connection. Quote Link to comment Share on other sites More sharing options...
Ulu Posted September 22, 2015 Report Share Posted September 22, 2015 My ground strap went from the battery to a generator bracket bolt on the block. There was a smaller one (maybe 4 Ga.) that went from a starter bolt to a screw in the firewall. There was a third smaller one from the firewall to the dash near the radio, maybe 8 Ga. The 4th one went from the inner fender bolt holding the solenoid, through the loom, to the firewall & was just 10Ga. That wasn't the factory arrangement at all, but it worked well. 1 Quote Link to comment Share on other sites More sharing options...
ggdad1951 Posted September 22, 2015 Report Share Posted September 22, 2015 from an engineering stand point ground straps are a crutch. You should have good ground thru the whole vehicle as it was designed. You also don't have to worry about ground loops. 2 Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted September 22, 2015 Report Share Posted September 22, 2015 Not entirely true. I just went through this with my local auto electric shop and my generator. We put the generator on the test bench and it tested out OK. I then brought in the regulator that had been on the truck and a new one. He hooked them up and tried it... nothing. Then polarized the Reg/Gen and it would attempt to charge. Then hooked up the new Regulator and tested it without polarizing and no charge. Polarized the new Reg and it charged good. So, if you are only polarizing the generator, and not the regulator, than why would the generator that was just polarized for the last regulator not work until the new regulator was polarized? Merle Merle, You should find this interesting. There is nothing in a voltage regulator that needs polarization. Note: Why do generators need to be "polarized"? Automobile generators need some magnetism to get started. This "residual" magnetism remains in the field pole pieces even after the engine has stopped. The next time the generator starts up, the residual magnetism creates a small voltage in the armature windings. Not enough to charge the battery, but enough to allow the field windings to draw current. As the field current increases, the pole pieces create even more magnetism. That makes even more voltage in the armature, and the cycle continues until the generator is capable of producing maximum output. Note: Voltage regulators do not need to be polarized -- they are not polarity sensitive. Even if voltage regulator came with instructions to polarize it -- these instructions actually polarize the generator, not the regulator. The regulator manufacturer simply wants to make sure that your generator will work properly so you don't blame the voltage regulator. 1 Quote Link to comment Share on other sites More sharing options...
Brent B3B Posted September 22, 2015 Report Share Posted September 22, 2015 good info, so if a guy was to have his generator rebuilt as a walk in, the shop doing the work should be able to polarize it at the same time, take it home and your good to go. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted September 23, 2015 Report Share Posted September 23, 2015 You need to polarize the generator and regulator when both are wired up correctly and installed on the car. That is if you need to at all. I most always do this. In the last 2-3 years I have had way too many issues with the new regulators failing. Quote Link to comment Share on other sites More sharing options...
HanksB3B Posted September 23, 2015 Report Share Posted September 23, 2015 good info, so if a guy was to have his generator rebuilt as a walk in, the shop doing the work should be able to polarize it at the same time, take it home and your good to go. Brent, Why leave something so simple in the hands of someone thinking Negative (ground) thoughts Hank Quote Link to comment Share on other sites More sharing options...
Ulu Posted September 23, 2015 Report Share Posted September 23, 2015 from an engineering stand point ground straps are a crutch. You should have good ground thru the whole vehicle as it was designed. You also don't have to worry about ground loops. Well there are those rubber engine mounts to get around. The whole body should have the same ground potential if it's not too old and rusty. Mine was old & rusty. 1 Quote Link to comment Share on other sites More sharing options...
TodFitch Posted September 23, 2015 Report Share Posted September 23, 2015 good info, so if a guy was to have his generator rebuilt as a walk in, the shop doing the work should be able to polarize it at the same time, take it home and your good to go. Yep. I've had generators that sat on my shelf for more than a decade that worked just perfectly . . . As long as there is a slight residual magnetic field in the iron cores the generator will work. And I don't see how a generator could be tested without setting up the field magnetism. So if it is not polarized then it was not tested. Maybe some generator repair shops assume negative ground and have it polarized incorrectly for our application. But if so, I'd seriously consider finding a different repair shop. Near as I can tell the only reason most people would need to polarize a generator is if someone had reversed the polarity. Possibly accidentally by installing a battery backwards or intentionally. Quote Link to comment Share on other sites More sharing options...
ggdad1951 Posted September 23, 2015 Report Share Posted September 23, 2015 Well there are those rubber engine mounts to get around. The whole body should have the same ground potential if it's not too old and rusty. Mine was old & rusty. FEF is grounded from the battery to the bell housing, no issue with any rubber mounts. The oil pressure sender should ground the cab (as well as the fenders, grill, hood, speedo cable, etc). Plenty of grounds already exist. Ground straps are a crutch, period. Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted September 23, 2015 Report Share Posted September 23, 2015 (edited) I would tend to agree with Mark.......but in reality it wont do any harm to add a ground strap. Lots of chassis grounded machinery comes equipped with redundant ground straps.The bottom line is you always want a good solid ground. Do what you have to do to make certain you have it grounded. By the description of what happened on the road though it sure sounds like there is a loose or bad connection somewhere between the generator and the ammeter. Either way best of luck tracing it down. This kind of stuff can be frustrating......you just have to use a process of elimination to pinpoint it. Jeff . Edited September 23, 2015 by Jeff Balazs Quote Link to comment Share on other sites More sharing options...
Young Ed Posted September 23, 2015 Report Share Posted September 23, 2015 Yes please check the connections on the back of the ammeter ASAP. I had what I thought was a non charging issue which turned out to be a lose connection. By the time I found it the wires had arced on the ammeter stud and it broke off when I tried to retighten. Quote Link to comment Share on other sites More sharing options...
TodFitch Posted September 23, 2015 Report Share Posted September 23, 2015 Yes please check the connections on the back of the ammeter ASAP. . . . Star lock washers ("external tooth shakeproof washers" to use terms from my old parts book) are your friend when securing lug wire connectors onto screws or studs. Quote Link to comment Share on other sites More sharing options...
DollyDodge Posted September 23, 2015 Author Report Share Posted September 23, 2015 Hey Merle: Not insulted. I am certain the wiring is correct, but I will check again. I have gone over it a dozen times. Both using the schematics that Rhode Island wiring gave me, and the shop manual. But I will check again. I have been known to mess up even after multiple checks. Mark and Jeff. I did check the wires on the back of ammeter (as that was suggested in the shop manual as well). I even took them both off and connected them together and bypassed the ammeter. It didn't help either. The ammeter (all the gauges) were rebuilt and as far as I know they are in great working order too. The wiring is all new from Rhode Island. I will get this figured out. From my perspective I feel better at least knowing the system worked for a few minutes. We will get it figured. One thing on another note, when I sent the generator to VPW they told me there was a disconnected wire in the generator when they got it. I wonder if the local guy even really checked it for me when he told me it was functioning fine. It is a process learning all this stuff, but DD is near being "healed" up and road worthy. I sure do appreciate all the input you all have given me. As I said above we will get if fixed! Quote Link to comment Share on other sites More sharing options...
cavisco1 Posted September 23, 2015 Report Share Posted September 23, 2015 You may have a bad crimp at one of the terminals. Even a good supplier of harness assemblies can sometimes crimp the terminal over the insulation resulting in an intermittent connection. You may have to tug/wiggle the wire at each terminal crimp while someone monitors the gauge. Good luck, Scott. 1 Quote Link to comment Share on other sites More sharing options...
Jeff Balazs Posted September 23, 2015 Report Share Posted September 23, 2015 You may have a bad crimp at one of the terminals. Even a good supplier of harness assemblies can sometimes crimp the terminal over the insulation resulting in an intermittent connection. You may have to tug/wiggle the wire at each terminal crimp while someone monitors the gauge. Good luck, Scott. Yep. Another thing you may have to try is making a few jumper wires and bypassing some of the harness with direct connections. You will find it...I have no doubt of that. Jeff Quote Link to comment Share on other sites More sharing options...
Young Ed Posted September 23, 2015 Report Share Posted September 23, 2015 Star lock washers ("external tooth shakeproof washers" to use terms from my old parts book) are your friend when securing lug wire connectors onto screws or studs. So is actually getting the wires tight Quote Link to comment Share on other sites More sharing options...
JBNeal Posted September 23, 2015 Report Share Posted September 23, 2015 on pristine assemblies, ground straps are a belt & suspenders approach to effective circuit grounding. When corrosion is present, ground straps are indeed a crutch that enhances a circuit encountering variable grounding impedance. Ground straps are designed into robust systems to account for the inevitable field contamination that leads to corrosion that can boost impedance sky high in low voltage systems...one gander at the grounds present on The Blue Bomber is an indication of how important the SAE thinks adequate grounding is on low voltage systems 1 Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted September 23, 2015 Report Share Posted September 23, 2015 Prior to retiring I was a field engineer for the company that maintains and upgrades all the bank note processing machines for the federal reserve banks all across the country. One of the things required when doing an upgrade was insuring that all ground straps (and there were a lot of them) were connected prior to the final inspection and returning the machines to service. We were also required to fabricate a cardboard rear door on these machines for testing purposes. On one occasion my boss (many of you know him as forum member Chet) was paying an inspection visit to the FRB in Seattle. Prior to his arrival I connected a ground strap to the temporary cardboard door to insure compliance. He found that and we all had a good laugh. 3 Quote Link to comment Share on other sites More sharing options...
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