reese Posted March 17, 2008 Report Share Posted March 17, 2008 I have a 74 620 with the stock 1.8L, one day the alt light started to flicker at start up and would go away after I drove for a minute. It happened for a week or so..then it stayed on all the time. Tested volts at battery and it was 15.5! with truck running. I replaced the alt with a rebuilt one but the light was still on. Replaced the volt reg, light goes out, drove it for a week with no light. Get in to leave, dead battery. Load test battery, old and no good. Bought new battery and cables. With everything new, I FINALLY get out the volt meter again and at the stud on the alt its 12.3v running at 1200 rpm..with lights on it drops to under 12v. I put old reg back on and it is 14v at the stud and charge light is still on. Is there any way to test the regulator, can I unhook the reg and test for voltage at the alt? Is there anything that will fry the alt or reg? I also unwrapped the harness and everything looked good, all stock and uncut. Truck never had electrical problems before, everything electrical works. What is next? Quote Link to comment
yello620 Posted March 17, 2008 Report Share Posted March 17, 2008 What is next? A conversion to an internally regulated unit. That factory Hitachi stuff is crap. And just because you have replaced these parts does not make them any good either. I have received numerous reman alternators that were BAD upon install. And dont even consider replacing the voltage regulator with a Napa Echlin brand. Complete Crap. Sorry i dont have the answer for you, mine has a 63A GM alternator installed by a previous owner. You might get ahold of Lynchfourtwenty, as he has been through a lot of this crap recently. Jason Quote Link to comment
slodat Posted March 17, 2008 Report Share Posted March 17, 2008 Erik, my recommendation is a conversion to an internally regulated alternator. Either the 280zx/720/200sx 50 or 60a or the Saturn. I recommend the Saturn if you are doing it. I'm happy to give guidance, if needed.. Quote Link to comment
reese Posted March 17, 2008 Author Report Share Posted March 17, 2008 Has anyone gone to an IR alt on a L16/18 motor? I tried a 82 720 but the larger case hit the idler arm or water neck on the block. There was very little clearance to adjust belt so I took it back and got the stock one. Is there a smaller 50amp IR one that goes on easier? How big is the Saturn one? Who has more info on this? Quote Link to comment
]2eDeYe Posted March 17, 2008 Report Share Posted March 17, 2008 I/R on a early 620? Hate to say it but do a bit of searching ;) A 280ZX waterneck will give you more clearance for a bigger alternator. Quote Link to comment
slodat Posted March 17, 2008 Report Share Posted March 17, 2008 The smallest IR alternator that I know of that fits L series easily is out of a '79 620. It is 35a. Quote Link to comment
420n620 Posted March 17, 2008 Report Share Posted March 17, 2008 when you install a new voltage reg, are you not to magnatize the new voltage reg, HUMMMMMMMMM ;) Quote Link to comment
banzai510(hainz) Posted March 17, 2008 Report Share Posted March 17, 2008 try another volt reg. If your sure that alternator is good!!!!! I would swap regs and get different results sometimes. I like the Wells brands solid state units. The IR are bigger and need mods to fit right due to the idler arm pivot poin location Quote Link to comment
reese Posted March 20, 2008 Author Report Share Posted March 20, 2008 Thanks for the help everyone..it was the regulator I bought a Baxters that was fked.. I bought another one and everything worked fine, at least now I have a new battery, cables, alt and reg. Hopefully that part of the 620 is good for a while. On to the rest of the broken shit.. Quote Link to comment
banzai510(hainz) Posted March 20, 2008 Report Share Posted March 20, 2008 PS DO not buy the USA made mechanical volt regs. they are bad news sold to NAPA under Elchin, or Neihoff brand. Ihad 2 go bad in 3 years. they OVERVOLT cooking the battery Buy the USA made Wells brand solid state ones Or maybe the Japam made mechanical ones buy a spare and keep it in the truck Quote Link to comment
reese Posted March 22, 2008 Author Report Share Posted March 22, 2008 The original one in my truck was an old looking non OEM SS one, it overcharged.. The one I got at Baxters was in a Standard box but was not a Standard, it was in a galvanized case and the wires were all different colors.. the one I got on Ebay was a Standard USA made Solid State with the same color wires as the stock harness.. I bought two for 9.99 each! http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=250167811675 Quote Link to comment
slodat Posted March 22, 2008 Report Share Posted March 22, 2008 glad you got it working! Quote Link to comment
hogboy52 Posted March 23, 2008 Report Share Posted March 23, 2008 My 75 620 with the stock regulator did the same thing; dash light on all the time though voltage was correct. I removed the regulator mounting screws then retightened them and it has worked correctly since. The dash light relay is grounded through the regulator body! Quote Link to comment
datzenmike Posted March 23, 2008 Report Share Posted March 23, 2008 Has anyone gone to an IR alt on a L16/18 motor? I tried a 82 720 but the larger case hit the idler arm or water neck on the block. There was very little clearance to adjust belt so I took it back and got the stock one. Is there a smaller 50amp IR one that goes on easier? How big is the Saturn one? Who has more info on this? Use the 720 mount to block and an L28 lower rad return pipe at the block and it will clear... barely. I had to put the tighter belt on first then the through bolts on the alt. 60 Amp! http://i138.photobucket.com/albums/q251/datzenmike/motoraltmountsZtopandL.jpg[/img]"] Quote Link to comment
Jester Posted March 24, 2008 Report Share Posted March 24, 2008 Just curious as to what Alt. is in a Datsun 810 sedan with the L24? IR or not? I found one at the local WY today. This thing was loaded with all kinds of power options and A/C. Figured the alt would be a big one. SO....I grabbed it and the lower mount. The mount had one stud in it for the forward most mounting point. Now I can see why. Pain the ass. You can't get the rear mounting bolt in (it's spaced differant than the original) but, it should work out just fine. Jester Quote Link to comment
datsunaholic Posted March 24, 2008 Report Share Posted March 24, 2008 Depends on what year 810. They went IR for the '78 model year, but the 810 had been around since '76. Quote Link to comment
Jester Posted March 24, 2008 Report Share Posted March 24, 2008 The paint marker on the fender said "79. I didn't see any regulator on the fender or under the plastic cover on the pass. side fender well. Should be good to go then, right? Jester BTW: I'm haveing the same problem Jimmy did. When I hook the Yellow and White wires together, the relay on the pass fender near the windshield clicks. Quote Link to comment
banzai510(hainz) Posted March 25, 2008 Report Share Posted March 25, 2008 I assume the 620 uses the same colors http://datsun510.com/photopost/showphoto.php?photo=124&size=big&papass=&sort=1 WB short to WR Y short to W short the the connector using jumpers wire incase you want to go back to stock. But i assume ytu know this already Quote Link to comment
Jester Posted March 26, 2008 Report Share Posted March 26, 2008 [quote=banzai510(hainz);48454 WB short to WR Y short to W Yep. That's what I did. BUT, when I hook up the yellow to white wire, the small relay by the windshield on the pass. side trips. IS THIS NORMAL????? Quote Link to comment
banzai510(hainz) Posted March 26, 2008 Report Share Posted March 26, 2008 You know wht I think it has to do with the choke relay. Look at the drawing again in the upper right. I assume the later 620s had this also. in the Dime Quarterly Eleltrical section has the right up on what the choke relay does. I dont have a eleltric choke option (relay)on my cars Im only guess is if you have a manual choke weber or sidedrafts you would just discconect that relay. If using a eleltric choke go back to Dime Quarterly and read the article on the relay on what to do. I still run external regs anyway Quote Link to comment
Jester Posted March 26, 2008 Report Share Posted March 26, 2008 Thanks Hainz. I appreciate the help. Quote Link to comment
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