mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 If I set idle with headlights on, then my idle when they’re off is too high. I never see the red charge light come on, ever. I’m running a 510 60A alternator, externally regulated. 2 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 57 minutes ago, thisismatt said: Another reason to go to an internally regulated alternator, or at least a solid state regulator I looked around for a solid state version with the right plug and haven’t found one yet. 1 Quote Link to comment
datzenmike Posted June 6, 2020 Report Share Posted June 6, 2020 44 minutes ago, mainer311 said: If I set idle with headlights on, then my idle when they’re off is too high. I never see the red charge light come on, ever. I’m running a 510 60A alternator, externally regulated. 850 isn't too high. It does come on with the ignition key before starting right? 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 (edited) 7 hours ago, datzenmike said: 850 isn't too high. It does come on with the ignition key before starting right? Yes. The light does work. Once my kid goes down for a nap today, I’ll check the ground wire. It only does it at “high idle,” and never any time else. Oddly enough, it only does it when it’s hot and the truck has been running for a few minutes. Edited June 6, 2020 by mainer311 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 I just went out and had a look. It’s the original Hitachi. Getting those screws out is going to be fun. 1 Quote Link to comment
datzenmike Posted June 6, 2020 Report Share Posted June 6, 2020 Just make sure they aren't loose and the outer case rattling but I guess a peak inside might be a good idea. Specially when it's making the noise. Everything seems to be working, it's just noisy. 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 Is the case what gets grounded? I don’t see any obvious ground wires to the case, and figure it gets grounded via the body. I’m going to see what impedance I get between the case and batt negative before I remove it. 1 Quote Link to comment
datzenmike Posted June 6, 2020 Report Share Posted June 6, 2020 Yes the regulator mount will ground it to the body. Some set ups use one of the mount screws as the attachment point for the battery ground to the body. My 710 has a body ground wire attachment under the battery tray. I also ran one from the engine bracket bolt a few inches to the mount bolt on the frame rail to be sure. 1 Quote Link to comment
DanielC Posted June 6, 2020 Report Share Posted June 6, 2020 (edited) I have not read many of the last recent posts, but I noticed a few things that are really important. The regulator MUST ground to the inner fender. There should be a thick ground wire from the head connection of the negative battery cable down to the frame of the alternator. In my opinion, if you have a higher amp alternator, this wire must larger to carry the greater current. There should be a thick ground wire from the case of the alternator to one of the bolts that hold the voltage regulator to the inner fender. It is vitally important that the battery, the alternator, and the regulator have as close to a perfect electrical connection as possible. How can the regulator regulate the voltage, if it does not know what the voltage of the battery and alternator are? The alternator must have a good ground to the cab sheet metal. If this ground goes away, the cab will try to ground through anything else it can, including the throttle cable. The throttle cable is too small to carry this current, it will get hot, and melt the plastic outer case of the throttle cable and destroy it. If you are driving the truck at speed or with a load when the throttle cable melts, you will be stuck with the throttle held open. This is not as important. A working external regulator and alternator are just fine. No need to switch to an internal regulator alternator. The stock external regulator will work fine with a higher amp alternator, the regulator does not measure current, only voltage. If possible, I prefer a 50 year old Nissan (Datsun) OEM regulator over a modern new regulator, including newer electronic regulators. The 50 year old regulator can fail, but I would suspect the failure is more likely caused by bad connections. Reread my first paragraph of this post. Edited June 6, 2020 by DanielC 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 (edited) I have a couple of those grounds. I have a huge wire going from batt neg to the front engine hoist bolt. There is also a huge wire jumpered there going to the alternator case, so I have the engine block, alternator, and battery well connected. I’ll need to check the body grounding, but I’ve never had any issues with the throttle cable...yet. Edited June 6, 2020 by mainer311 2 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 Upon closer inspection, I do see the ground wire going to the VR case. Reading 0.6ohms to the battery negative. 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 Well, it’s apart. It looks very clean on the inside. Some resistors, 2 relays, and a bunch of wires going everywhere. I’m really good with electronics, but this is voodoo magic. I understand how it works (square waves) but this is beyond me. I’m currently cleaning both halves of the connector with lemon juice to get rid of all the crud. I can see how these are adjustable by messing with the spring tension on the relay, but I’m not going to mess with it. 1 Quote Link to comment
MikeRL411 Posted June 6, 2020 Report Share Posted June 6, 2020 1 minute ago, mainer311 said: Well, it’s apart. It looks very clean on the inside. Some resistors, 2 relays, and a bunch of wires going everywhere. I’m really good with electronics, but this is voodoo magic. I understand how it works (square waves) but this is beyond me. I’m currently cleaning both halves of the connector with lemon juice to get rid of all the crud. I can see how these are adjustable by messing with the spring tension on the relay, but I’m not going to mess with it. There is actually a written procedure for adjusting the mechanical voltage regulator. After reading it I bought an electronic plug and play unit. A hell of a lot simpler solution. It has worked for over 40 years with no problems, couldn't say that about a mechanical regulator. 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 35 minutes ago, MikeRL411 said: There is actually a written procedure for adjusting the mechanical voltage regulator. After reading it I bought an electronic plug and play unit. A hell of a lot simpler solution. It has worked for over 40 years with no problems, couldn't say that about a mechanical regulator. Any idea what it was? Probably not if it was 40 years ago. I’ve been looking and Autozone has one that is supposedly made by Wells. It’s very short, so I’m thinking it’s an electronic unit. 1 Quote Link to comment
Crashtd420 Posted June 6, 2020 Report Share Posted June 6, 2020 Why not just do the conversation to the internally regulated altenator and just be done with it..... I have the same altenator you have and 2 regulators sitting on my shelf .... I was so happy to switch it over..... I have a part number if you want..... I believe its 50/60 Amps and exactly the same size as what you have.... 1 Quote Link to comment
mainer311 Posted June 6, 2020 Author Report Share Posted June 6, 2020 Sure, send over the part number if you have one. I just hate replacing stuff that is practically brand new. If I throw this VR back on and the voltages look okay, I’m just going to live with it until it melts down. 3 Quote Link to comment
datzenmike Posted June 7, 2020 Report Share Posted June 7, 2020 The earliest PL521 alternator was 33 amp, the '72 was 35 amps same as the '73 and up 620, although there was a 38 amp optional alternator from '77 on. These alternators are small diameter and putting a much larger diameter car 50/60 amp alternator in is a tight fit. The lower rad return hose is above it, around the side and even in front of it and the idler arm below it. It's so tight to the block there's little adjustment room to swing it. 2 Quote Link to comment
Crashtd420 Posted June 7, 2020 Report Share Posted June 7, 2020 4 minutes ago, mainer311 said: Sure, send over the part number if you have one. I just hate replacing stuff that is practically brand new. If I throw this VR back on and the voltages look okay, I’m just going to live with it until it melts down. I know what you mean.... I have extras to prove it..... I'll send you the part number tomorrow... 1 Quote Link to comment
mainer311 Posted June 7, 2020 Author Report Share Posted June 7, 2020 Thanks boss 2 Quote Link to comment
Crashtd420 Posted June 7, 2020 Report Share Posted June 7, 2020 4 minutes ago, datzenmike said: The earliest PL521 alternator was 33 amp, the '72 was 35 amps same as the '73 and up 620, although there was a 38 amp optional alternator from '77 on. These alternators are small diameter and putting a much larger diameter car 50/60 amp alternator in is a tight fit. The lower rad return hose is above it, around the side and even in front of it and the idler arm below it. It's so tight to the block there's little adjustment room to swing it. It is a tight fit but it does fit... mainer311 already has the larger one installed just the externally regulated one.... so he has the right belt and clearance.... 1 Quote Link to comment
mainer311 Posted June 7, 2020 Author Report Share Posted June 7, 2020 Well, it’s back together, but I won’t know if it makes noise until I take it for a cruise. Battery baseline: 12.75 Truck at idle (750ish): 13.50 Truck with lights on: 13.30 (doesn’t change no matter what RPM) Lights off, cruising RPM: 14.8-15.1 3 Quote Link to comment
Crashtd420 Posted June 7, 2020 Report Share Posted June 7, 2020 Gettiing to 15v seems a little high, I didn't think you wanted to see much more than 14.4.... the rest seems right.. Well if you do decided to switch it over The alternator you want to look for is for a 1980 nissan 200sx.... I got the 60amp from oriellys.. Haines has been trying the new power select units from rockauto... haven't heard him say anything bad about them yet. Oh keep these little ,whatever they are.. They are for the ears on the altenator, since we use a slightly smaller bolt to attach to the engine bracket.... or drill the engine bracket for the bigger bolts .. either would work... Just to point out there are better amperage upgrades out there but this is the easiest swap, .... I am eventually looking into getting around 100amp alternator, but all those seem to have something that needs to be swapped or modified....I'll save that for a winter project .... 2 Quote Link to comment
datzenmike Posted June 7, 2020 Report Share Posted June 7, 2020 The regulator is temperature compensating. The specs below are for the 710 but alternators are alternators and batteries are batteries. At 14F the output is between 14.75 and 15.75 At 68F it's between 14.3 and 15.3 At 104F it's between 14.0 and 15.0 3 Quote Link to comment
Crashtd420 Posted June 7, 2020 Report Share Posted June 7, 2020 Interesting information.... 1 Quote Link to comment
Stoffregen Motorsports Posted June 7, 2020 Report Share Posted June 7, 2020 I like the idea of drilling to accept 10mm bolts. The factory 8mm bolts are weak and tend to break. Note - somewhere along the line, Nissan upgraded to 10mm bolts, but I don't know the cutoff date. 2 Quote Link to comment
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