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| Light surging issues https://slantsix.org/forum/viewtopic.php?t=51417 |
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| Author: | aspen76 [ Fri Mar 15, 2013 4:54 pm ] |
| Post subject: | Light surging issues |
Hey guys, I'm having some issues with my lights surging when I put the engine under load. I've recorded a video that you guys can watch here. A few weeks ago my dash illumination lights went completely out (not my brake, oil, and turn lights). I checked my fuses and everything seemed ok (I will note that there was one fuse missing, I added a new fuse and I can't seem to figure out what it did, all I know is there is power going through it at all times when the car is on). Since my speedo doesn't work as it is, I didn't think it was a big deal yet, something to address later. Well last weekend I went to a car wash and ever since my car has been doing this light surging thing. When I'm driving under steady throttle, you can hear the car go under heavier loads when the lights flash brighter. I don't depend on this car on a daily basis any more and am capable of really getting in there but not sure where to even look. This, of course, had to come on the weekend I had been planning to do my HEI swap. Which, will have to be put off because I'm not going to potentially confound issues by adding more potential problems. Thanks for any and all help, Aspen76 |
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| Author: | DusterIdiot [ Fri Mar 15, 2013 6:23 pm ] |
| Post subject: | Hmmm... |
What brand of alternator are you running (and output), and have you checked your ground attachments under the dash and in the engine bay? Just a thought. -D.Idiot |
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| Author: | aspen76 [ Fri Mar 15, 2013 7:25 pm ] |
| Post subject: | |
The new alternator is this one. 120A. I've run two additional charge wires direct to my positive terminal with both sides of each wire 50 amp fused (per SSDan's recommendation). I beleive the grounds in the engine be are good, or at least appear to be solidly grounded. I haven't checked under my dash yet, I hate getting in those tight spots lol. My thought is that there is an exposed positive wire somewhere grounding out. This is causing my lights to be dim under no load but brighten up once the alt kicks in. This grounding is causing my alt to kick into high gear with the output, putting my strain on my engine, which would explain the sound of going up a hill when my lights flash brighter. My biggest suspect is up under the dash at the wire that supplies power to the dash lights. I think the dash lights only come on when I have my headlights on, so the light surges (on my tach) should only happen with the head lights are on if thats the case. I have to rely on my vehicle tomorrow for the first time in a few weeks, good time to test my theory. I'll definitely be bringing a fire extinguisher. If anyone think I'm way off, please point me in the right direction, I appreciate all help, Aspen76 |
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| Author: | DusterIdiot [ Fri Mar 15, 2013 8:33 pm ] |
| Post subject: | Engine Bay not engine.... |
The 1976 has ground for the head lights up by the radiator support at the front of the car... if one has cracked or degraded from corrosion or being 40 years old...it will use the path of least resistance for grounding which can be our instrument cluster light circuit ( this is a common 'ooops' on 1976 A-bodies as well, and helps to upgrade the ground- a mass of 20 gauge wires to something a bit bigger and better). -D.Idiot "Been there, did that before..." |
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| Author: | aspen76 [ Sat Mar 16, 2013 8:21 am ] |
| Post subject: | |
I just examined all my wires under my hood and all seems to be well insulated. All the wires going to my head lights are wrapped together in, what seems to be, thick electric tape from the firewall to the lights. I checked the ground from the head lights and it was running to a bolt under the hood which had also had a wire running from the bolt directly to the negative terminal of the battery. I checked my alternator wires to make sure the wires were still secure and one of my regulator wires was starting to strain out but still securely attached. I need to figure out a way to reduce the vibration on my alt, It seems pretty extreme even though I have all the mounting bolts tighten down as tight as I can possibly get them. I checked my tach light with the head lights off and it still dims at idle and brightens under load. I could also hear the engine being put under load and then removed while sitting at idle and at steady throttle. I have to drive it a few miles down the road in an hour, hopefully it makes it without issue so I can spend some time with it the rest of the weekend. Thanks for the help, Aspen76 |
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| Author: | DusterIdiot [ Sat Mar 16, 2013 8:25 am ] |
| Post subject: | What brand alternator? |
Just curious was it a duralast alternator as your link showed? -D.Idiot |
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| Author: | Aggressive Ted [ Sat Mar 16, 2013 10:59 am ] |
| Post subject: | |
Quote: When I'm driving under steady throttle, you can hear the car go under heavier loads when the lights flash brighter.
1. Did you run a ground strap from the voltage regulator to the alternator? 2. How old is your voltage regulator? 3. Do you have a spare for testing? 4. Did you change the negative cable on the battery? I just did the double 10 gauge rewire before winter like you have done but with a new stock alternator. I have noticed that the engine does surge at a light and when I look at the volt meter I see it swinging 2 or 3 volts (13.5 to 16.5v) at a 600 rpm idle. Yes, the lights flash. So I have been trying different regulators to reduce the effect. I haven't found a good one yet....even my new Echlin. They all seem to cause this surging at light electrical loads. If I load the electrical system hard, wipers headlights, radio, heater fan on full, electric fans on, then it settles down and quits surging at a solid 13.5 volts. I can imagine that a 100 amp alternator would make a significant surge and do it any time. I just haven't found a good regulator to smooth it out yet. It is interesting that the old stock wiring never did this and absorbed the peaks....but the upgrade wiring sure brought it out! |
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| Author: | TonyPgh [ Sat Mar 16, 2013 7:10 pm ] |
| Post subject: | |
Quote: Quote: When I'm driving under steady throttle, you can hear the car go under heavier loads when the lights flash brighter.
1. Did you run a ground strap from the voltage regulator to the alternator? 2. How old is your voltage regulator? 3. Do you have a spare for testing? 4. Did you change the negative cable on the battery? I just did the double 10 gauge rewire before winter like you have done but with a new stock alternator. I have noticed that the engine does surge at a light and when I look at the volt meter I see it swinging 2 or 3 volts (13.5 to 16.5v) at a 600 rpm idle. Yes, the lights flash. So I have been trying different regulators to reduce the effect. I haven't found a good one yet....even my new Echlin. They all seem to cause this surging at light electrical loads. If I load the electrical system hard, wipers headlights, radio, heater fan on full, electric fans on, then it settles down and quits surging at a solid 13.5 volts. I can imagine that a 100 amp alternator would make a significant surge and do it any time. I just haven't found a good regulator to smooth it out yet. It is interesting that the old stock wiring never did this and absorbed the peaks....but the upgrade wiring sure brought it out! |
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| Author: | Aggressive Ted [ Sat Mar 16, 2013 9:18 pm ] |
| Post subject: | |
Yes, read SL6 Dan's recommendations for the past 15 years. Most folks never clean the paint off the mounting tabs so the voltage regulator may not see a good ground. |
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| Author: | DusterIdiot [ Sat Mar 16, 2013 9:24 pm ] |
| Post subject: | No.... |
Quote: but is there supposed to be a ground strap from the voltage regulator to the alternator? I don't see one on my 71 Valiant?
There won't be one from the factory...in the 60's you will have a wire going from the engine block to the firewall, sometimes, mostly it's the battery cable to the block. On 70's cars, they went to add a braided cable from the head to the firewall for more direct ground....To improve this for a much more complete system, then the SSD upgrade is the best bet as the factory only did the minimum of what was necessary at the time on the smallest budget... -D.Idiot |
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| Author: | olafla [ Sat Mar 16, 2013 10:02 pm ] |
| Post subject: | |
I had flickering of the lights in my Aspen, but not as pronounced as yours. Mine were also more regular, and did not wary in intensity as much. I tried several voltage regulators I have, but the problem turned out to be a defect diode in the diode bridge in the alternator. I switched to a 3-wire GM alternator I had. The Piper Cherokee airplane used a Mopar setup for charging. If you really want to know your charging system in detail, you should read this commented overview, it's the best I've seen. http://flymall.org/aircraft/docs/Piper- ... System.pdf Olaf |
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| Author: | TonyPgh [ Sun Mar 17, 2013 7:26 am ] |
| Post subject: | Re: No.... |
Quote: Quote: but is there supposed to be a ground strap from the voltage regulator to the alternator? I don't see one on my 71 Valiant?
There won't be one from the factory...in the 60's you will have a wire going from the engine block to the firewall, sometimes, mostly it's the battery cable to the block. On 70's cars, they went to add a braided cable from the head to the firewall for more direct ground....To improve this for a much more complete system, then the SSD upgrade is the best bet as the factory only did the minimum of what was necessary at the time on the smallest budget... -D.Idiot |
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| Author: | DusterIdiot [ Sun Mar 17, 2013 9:20 am ] |
| Post subject: | Yes.... |
Quote: Do I just add a wire from a bolt on the regulator to the bracket of the alternator?
That'd do it.
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| Author: | TonyPgh [ Sun Mar 17, 2013 2:29 pm ] |
| Post subject: | Re: Yes.... |
Quote: Quote: Do I just add a wire from a bolt on the regulator to the bracket of the alternator?
That'd do it.My alternator has a stud with a nut that says "grnd"..I guess that needs grounded too. No wonder mine is always at 14.8 volts. My grounds arent there |
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| Author: | aspen76 [ Wed Mar 20, 2013 7:32 pm ] |
| Post subject: | |
I've been busy for a few days but the car survived my trip down the street. The alternator is definitely engaging at full load randomly while under load, very pronounced at 50 mph. Anyone have the link to SSD's ground strap recommendation? I know it's not in place if it weren't factory. My voltage regulator is brand new (from Napa), replaced it when I changed my alt. That alt I linked is the exact one I have. I know there was plenty of warning regarding Chinese copy cat alts but there was no alternative options (this seemed to be the best option). If it turns out to be the alt again, I'll go pull one out of the junkyard and pay for it to be rebuilt as I'm a little more financially secure then when I initially did the swap. This is my second alt during this swap, my first was a $30 alt off of rockauto and it never worked for a second (should have known). The part that really gets me about this whole thing is that this came out of now where. The swap seemed to be a success until the car wash. On the subject of my alt, it seems to be vibrating excessively. The bolts are all as tight as possible. Is there any thing I can do it stop it from vibrating so much? Can I get rubber disks and use them as washer on the mounting bolts to help? Thanks for all the help, Aspen76 |
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