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09-29-2018, 09:48 PM | #1 |
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Re: At my wit's end, please help
Here's another thread with good alternator and wiring upgrade discussion
http://67-72chevytrucks.com/vboard/s...d.php?t=763180 |
09-30-2018, 11:49 AM | #2 |
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Re: At my wit's end, please help
The alternator makes the power and it is regulated by the voltage regulator.
If the contacts stick closed in the V regulator then the alternator has no governor to control it when running. It will max it's self out and this is why you have 17-18 + volts. Just some food for though. A 1 wire alternator will work but it want have the capability to control the charge like the 3 wire. A 1 wire will charge at the same amount no matter what the load is on the battery are the rpm of the motor, where a 3 wire will only charge at a rate enough to keep the battery at a constant charge so it want ever under charge it are over charge it.
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
09-30-2018, 12:31 PM | #3 | |
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Re: At my wit's end, please help
Quote:
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09-30-2018, 12:35 PM | #4 |
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Re: At my wit's end, please help
I would like to verify some of the facts here. First off are you running an alternator and regulator set like pictured below?
Now the time line. Several months back you added new fans and relays to operate them as well a a relay for the compressor clutch. Shortly after that your fusible link failed. Then several weeks ago you installed a new alternator. And shortly afterwards you had several wires melt down. You said you changed the alternator as it was noisy. The new alternator was an 80 amp unit instead of the factory 62 amp unit shown above. At this time you problems getting the charging system to operate which you solved by swapping several regulators before going back to the old one and adjusting it. The new 80 amp alternator was damaged when the wires melted? It was replaced with another 80 amp alternator? You have installed a voltmeter and disconnected your amp meter? Firedemon's link to madelectrical will help explain the difference between 1 and 3 wire systems in a coherent manner. That will give you the knowledge to decide which way to go if you are going to change to a newer internal regulated system.
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377 Last edited by HO455; 09-30-2018 at 12:41 PM. |
09-30-2018, 01:38 PM | #5 | ||||
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Re: At my wit's end, please help
Quote:
And this regulator Quote:
The old OEM alternator was noisy and I replaced it with a new 80A unit. At the same time, I added the fans. Shortly after that, the system overcharged and melted wires from the alternator to the regulator. The alternator was thought to be shorted internally so we replaced it with a new identical 80A unit and repaired the melted wiring. System was still overcharging and new regulators didn't fix it. At this point, the old regulator was re-installed and adjusted, and things seemed normal. Several days later the fusible link blew. I was in traffic and failed to notice if the ammeter showed an excessively high rate of charge. I had been running A/C at the time and after re-attaching the remains of the fusible link, I made it home (well over an hour) without using A/C, just in case that was the problem. I have since replaced the fusible link and added a relay for the compressor. Still dealing with a too-high rate of charge, which is where we are now. Quote:
Quote:
I have decided to get a 3-wire, 12SI, 94A internally regulated alternator. If I have trouble finding a 94A unit, I'll try for a 100A -- they seem to be fairly common.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 09-30-2018 at 02:56 PM. |
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09-30-2018, 12:35 PM | #6 |
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Re: At my wit's end, please help
An 80 amp alt. draws too much field current for a standard point type regulator. It will burn the points & make them stick. You need an internal regulated alt. or solid state regulator.
George |
09-30-2018, 07:13 PM | #7 |
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Re: At my wit's end, please help
I appreciate any input I can get.... it all helps.
My original alternator was a 61A (maybe 62A?) Still, an 80A can put out more current -- but isn't it supposed to put out whatever the load calls for? In other words, it's not going to pour out 80 amps all the time, only the amount asked for by the truck. That's my understanding, though I may be wrong. You are correct that I did not increase any wire sizes. I do not know which wires, specifically, would need to be beefed up. Can you offer any advice about that? The fans are powered by a relay wired to the junction block on the fender -- effectively the + batt post -- not through the fusibile link.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
09-30-2018, 08:58 PM | #8 |
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Re: At my wit's end, please help
First off I apologize somehow I got the idea your truck was a 67 thus the tangent off on the other alternator styles. The wires to be upsized would be the alternator output wire (red 12 guage on 1/4-20 bolt on the back of the alternator. And the battery charging wire (red 12 guage wire at junction block next to battery). I recommend you look at the first link for a good explanation of what wire is which and what size to go to and why. The quick answer is change the battery charging wire to a 10 guage and the alternator output wire to an 8 guage if your going for the 94 plus amperage alternator.
If you look at their Chevy diagram and compare it to a 67-72 C10 wiring diagram (2nd link) it is pretty easy to understand what they are talking about as it applies to our trucks. Trucks went away from the horn relay wiring they talk about on pre71 years earlier than cars did, but they didn't go to charging the battery through the starter in 71 like the cars did. http://www.madelectrical.com/electri...evymain2.shtml http://outintheshop.com/faq/wiring/wiring.htm
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Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban (the WMB),1988 S10 Blazer (the Stink10 II),1969 GTO (the Goat), 1970 Javelin, 1952 F2 Ford OHC six 4X4, 29 Model A, 72 Firebird (the DBP Bird). 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377 |
09-30-2018, 09:12 PM | #9 | |
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Re: At my wit's end, please help
Quote:
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
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10-01-2018, 07:41 AM | #10 |
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Re: At my wit's end, please help
Electrical is my weak point. I do have an understanding of the particular functions of most things electrical on these trucks through experience, though. I just don't have a full understanding to be the one giving advise. I am an advise taker in this area.
I have never experienced an overcharging system, yet I feel your issue is similar or the same as one I had in my old blue & white K20. I kept smelling rotten eggs and I never hauled eggs in it. Never saw a bird nest under the hood (at least not near anything real hot). It seemed to be coming from under the hood. I noticed the battery was warm enough to cook an egg, but no eggs in sight. It was a new optima marine battery. IIRC, I got to my old shop and the starter wouldn't crank. The purple(?) wire didn't look good so I went with new from the fuse block. Fixed that problem but still the rotten egg smell. I went with an later internal regulator alternator and the smell ended. I never considered that a one wire set-up. It used the two wire plug on the alternator and harness and eliminated the white(?) wire to the voltage regulator. Everything was still there if I every wanted to go back to original. It was really easy and straight forward. I hate the smell of rotten eggs. I'm glad I didn't get any on me or my truck. That could hurt. * Spoda be sumwut silly story based on actual experience
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10-01-2018, 02:45 PM | #11 |
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Re: At my wit's end, please help
Trying to stay on top of the details but I always have doubts....
In the original meltdown, the truck had been running fine, then suddenly started pegging the ammeter, then everything went dead. The mechanic said the alternator had an internal short which caused the meltdown. I have not experienced a battery drain throughout all of this. *the alternator will only output enough amps to run the loads and charge the battery* that's always been my understanding too.... I went with a higher rated replacement alternator only because of the additional current draw of the fans. I am in the process of upgrading the wiring based on advise in this thread. Yes, as I posted above, I ran the compressor wire through a relay. The fans were initially wired through a relay. I have read a few links on converting to an SI series alternator. I have ordered a 94A 12SI internally regulated alternator and it should be here tomorrow. I agree completely, I have gotten great advise & help in this thread, and I appreciate it very much. As to my current progress today, I have replaced the 12ga red wire from the fusibile link to the point where all the red wires join. It is now a 10 ga. wire. I need to get a length of 8ga to run from that point (don't know what to call it) to the lug on the alternator. Then extend the brown and red wires from the old regulator to the terminals on the alternator.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 10-01-2018 at 03:54 PM. |
10-02-2018, 12:07 PM | #12 |
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Re: At my wit's end, please help
Make sure all your ground straps are in place with clean tight connections. Spinning up 18 volts seems unusually high? That got me to wondering what the pulley diameters were between alternators, sometimes that makes a difference. I have a chrome 100amp one wire alt. on my BB truck, no problems in 3 years. I have an internally regulated alt. with the blue and white wires in place on the SB daily driver, no problems there either. I did make my own ground straps and added an extra strap from the block to frame and frame to inner fender insuring that rinky dink factory strap at the back of the motor wasn't getting over worked with a degraded connection from the valve cover to the firewall. One of the reasons I drive a 72 Chevy is there are no computers to present problems my 60 year old mind cant cypher. Tim, that rotten egg smell happens to me once in awhile, usually sumpthin I ate. Good luck
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10-02-2018, 03:57 PM | #13 |
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Re: At my wit's end, please help
I never have checked / reinforced my ground straps -- guess that would be a good project one of these days. In 41 years, I never had electrical problems until installing that 80A externally regulated alternator. That's when things started to go south. I think it speaks volumes for the goodness of the original design and hardware of these trucks. Disclaimer, I replaced a bendix drive on the starter many years ago. That's it, still the original starter and until now, the original alternator. Not bad at all. EDIT: Ironangel, you mentioned pulley diameters -- they have all been the same at 2 1/2".
Oh by the way Good News everyone! The new internally regulated alternator is on and seems to be working perfectly! It's outputting 14.5 volts at idle, and drops to just under 13 with A/C on (and sloooww idle, not sure just how slow). If it stays like this I will be one very happy camper! I want to thank everyone again. I never could have fixed this without you. Board members here are some of the best anywhere!
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 10-02-2018 at 11:55 PM. |
10-02-2018, 09:36 PM | #14 |
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Re: At my wit's end, please help
Good news! Alternator charging at idle should be 13.5 Volts minimum in order to push the electrons back into the battery. The 14.5 Volts is a good number for when the engine speed comes up. Look into what your idle speed is, since if you spend a lot of time idling, the battery can get discharged too much.
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10-02-2018, 11:23 PM | #15 |
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Re: At my wit's end, please help
Luckily I don't spend much time idling, but I'll check the idle RPM anyway just so I will know. The RPM is fine with A/C off, but goes down a fair amount when the compressor engages, and the draw from the fans might have a slight impact too. Should have checked idle speed today but I was too busy celebrating that the new alternator actually worked!
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
10-03-2018, 06:23 AM | #16 |
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Re: At my wit's end, please help
Glad it worked out and seems to be doing it's job for you.
At idle with ac on and in gear you should try for 650 RPM's min. Main thing is make sure the lights and other accessories don't flicker are deem at idle.
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
10-03-2018, 02:47 PM | #17 | |
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Re: At my wit's end, please help
Quote:
Fast idle, choke on: AC off, 1000 rpm, 14.67v AC on, 750 rpm, 14.58v AC on, in gear, 650 rpm, 14.30v Engine warm, choke off: AC off, 750 rpm, 14.56v AC on, 600 rpm, 13.23v AC on, in gear, 550 rpm, 12.40v Voltage reading is steady with AC off, fluctuates a few tenths with AC on. Headlamps dim slightly (nothing flickers) at idle when AC is turned on. Frankly, at this point I'm not concerned about it. Side note: The LED bulb in my dome lamp chose this exact moment to flicker and then die. I'm thinking just great, that's what I need is more electrical problems. Turns out it was a failed bulb, and I had one (standard, not LED) on hand.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
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10-03-2018, 03:10 PM | #18 | |
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Re: At my wit's end, please help
Quote:
You should idle up with the motor warm no choke on to around 650 in gear maybe 600 just depends on your self really. With the choke on it's going to idle pretty high which is what it's for to warm it up in the winter time.
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
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10-03-2018, 03:57 PM | #19 |
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Re: At my wit's end, please help
Done. 650 rpm idling in neutral w/AC on, drops to 600 in gear w/AC. Neutral w/AC off idles at 1000 rpm which seems high to me but I can live with it. I can always adjust it back down a tad if it bothers me.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
10-03-2018, 12:17 PM | #20 |
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Re: At my wit's end, please help
Congratulations on the fix. It proves that if you stay with it you can solve most of the electrical problems on our trucks with the help of the guys on this forum.
It's been an interesting thread to say the least and I hope it helps a lot of the viewers. One comment I would like to add is pertaining to the last post about idle charging being lower. Even the SI alternators are prone to this, and that's why I usually recommend going straight to the CS 130 or CS 144 style. They put out more charge at idle than the SI when a load is heavy at idle. They are just as easy to convert, are way more plentiful, and good used units are cheap.
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10-03-2018, 05:28 PM | #21 |
20' Daredevil (Ret)
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Re: At my wit's end, please help
Well, that 1000 rpm didn't last long. I backed it off to 950, a number I think I can live with. For whatever reason, my engine has always shut off *right now* with no after-run, even from a 1000 rpm idle. I often shut it off in gear anyway, but if I forget and put it in Park, it still shuts off quickly. That's a good tip though.....!
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay |
10-03-2018, 08:34 PM | #22 | |
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Re: At my wit's end, please help
Quote:
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1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
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10-04-2018, 07:24 AM | #23 |
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Re: At my wit's end, please help
Glad it is working again.
Now you need to keep it that way. You need to increase the size of the wire from the alternator to the battery to handle the increased load that the new alternator can put out. With the stock size charge wire you are limiting the ability of the new alternator to do its job at best and at worst risking another melt down if the alternator tries to push too much juice through too small of a wire. The stock wiring on most of the late model rigs with the high amp 12si that I have pulled apart have had 8-gauge wire and one with a longer travel path through the harness had 6-gauge. Pulling the wiring out of a new body style 88-up truck will give you the size you need with the correct ring terminal already in place on one end along with the terminal cover to match so that is where I would start unless it is easier for you to get new stranded 8-gauge wire and the right size ring terninals. Make sure the alternator case has a good ground back to the battery as well. This will help you get the most out of what you have. I run a case ground wire back to the battery just to make sure there is a good path of travel to complete the charge circuit to take full advantage of what the alternator can do.
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10-04-2018, 09:07 AM | #24 |
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Re: At my wit's end, please help
Per HO455's advice in post #32 "The quick answer is change the battery charging wire to a 10 guage and the alternator output wire to an 8 guage if your going for the 94 plus amperage alternator". This is what I did, and I soldered a proper ring terminal on the 8ga. wire for the alternator lug. I connected a ground wire to the alternator bracket for now, and will plan on running a ground wire back to the battery just to be sure.
EDIT: Just ran a new ground wire from the ground on the fender (which is connected directly to the battery) to the alternator.... one more little detail out of the way. Thanks for the good advice. As a couple members have said, there is a wealth of info in this thread and it should be helpful to others who might experience similar problems.
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- Mike - 1972 K20 LWB 350/350/205 RIP El Jay Last edited by Stocker; 10-04-2018 at 09:19 PM. Reason: Added info |
10-04-2018, 09:40 AM | #25 |
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Re: At my wit's end, please help
I'm glad you have it up and running with a good charge.
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