I have been working on my cooling issue, long thread over in the engine section and an electrical issue seems to have popped up. There has been some great suggestions on my cooling thread, but wanted to get other insight as well.
So after installing new electric fans, i noted the voltage dropping to 8volts on the volt gauge once the fans kick on.
I suspected the Alternator was not able to keep up. however, I removed the electrical fans and used the clutch fan, and after a short drive the gage dropped back to 8.
At idle the alt put out a little more than 12 volts, never more even at higher RPMs.
Last year I smoked the battery due to a wiring issue on the VR. I fixed the wiring and added a new AGM Battery. That was recently tested and seems to be OK.
I have done the Mad Electrical Amp Meter bypass.
The ignition box is new last year. I did not notice any electrical issues the first time out this summer,
This all started after the fan install, but continued with the fans disconnected. Could it be an issue with the relay I install for the fans?
Current suggestions are the verify all the grounds and connections are good and do not have any resistance.
Ground the Feild wire to see what the output is. Does it mater which field wire gores where?
Any help would be appreciated.
Jas, the one thing I can comment on is the alternator output. 12 volts just won't cut it. I typically look for an output voltage of 14 or a wee bit better. Do you have another alternator?
Will a 50 year old alternator charge an AGM battery correctly? Also you should be seeing 13.5 volts or more when the car is running....not much help I know
If you are adding additional electrical items like fans, then get a Powermaster alternator.
I installed one 2 years ago when I added a Holley Sniper.
For the battery to be " ok" it needs to be fully charged. Do not try to charge a battery with your cars alternator. It is not designed to do that. You can damage your alternator.
Battery chargers are designed to do that. The battery than needs to be load tested and pass.
After surface charge is taken off it should load @50% of CCA rating to no less than 9.7 volts. If it does, no good.
Naturally recheck all electrical connections and grounds. Not just a jiggle test.
Your Alt is dead , don't waste $$ on Powermaster junk either , I have seen them last less than 1 day .
With a charged battery you should have 14.2 v minimum.
no it doesn't matter which wire goes where on the Alt it is just a closed circuit in & out although usuall one wires is a bit shorter & only reaches the top terminal easily .
If I remember right, leave the blue wire on, ground the other. Should prove out whether your alt CAN put out over 12v if commanded to. If it goes over 14v you have a resistance problem, re wiring or VR. If it doesn't, you have an alt problem. Dropping quickly to 8v without significant load may indicate your battery has been killed though...
FYI...My mopar alt charges at 14.1-14.3 at idle after starting and drops to about 13.6-13.8 after a bit.
Ground the terminal that green wire goes to to bypass the voltage regulator
here's a decent step by step video https://youtu.be/uxVwuF5SI90?t=175
Just bringing over Brad's offer with his link.
Same price? I've had them on my cars for over 10 years now with no issues? These do actually charge at idle, unlike mopar alternators sometime struggle doing this? :alan2cents:
:thinking: I also have a spare I could lend you to try if you want? I have the same alternator on both the Challenger and the Javelin, and one spare.
https://www.qualitypowerauto.com/catalog.php?item=557
New VR installed today...first fire up and the volt meter was 15 pluss.
Checked the alt with the multimeter and it read 15.67 volts
So :woohoo: :woohoo: :woohoo: time for a test-drive!!!!!
Or is that too high?!?!? :pullinghair:
:veryexcited: Still have plan to replace the stock alternator to accommodate the draw from the electric fans?
I believe that 15+volts is to high. I would charge the battery fully with a battery charger and if the situation continues suspect the new VR is bad or the Blue wire that the VR reads the need has poor connections or degraded wires.
Quote from: Bullitt- on June 09, 2023, 03:26:06 PM
I believe that 15+volts is to high. I would charge the battery fully with a battery charger and if the situation continues suspect the new VR is bad or the Blue wire that the VR reads the need has poor connections or degraded wires.
:pullinghair: :pullinghair: :pullinghair:
Never mind. I just put the old VR back on just to see if the new one was bad. With the old one, reading over 16volts!!!!
Maybe to old one is bad???
I will pit the new one back on and check the wires. The wires are all new as I redid that part of the harness last year.
Do you know how to perform a voltage drop test? I have been searching for a relatable video but most are bench tests with minimal losses. This one focuses on the battery terminal but can be conducted between any two points in a circuit for instance you could put one lead on the + battery terminal and the other to the VR connector with the Blue wire (with ignition in run position) to see how much loss there is total. I believe .5V or less is acceptable. If it's higher you can break it down into smaller segments to see where the problem lies.
https://youtu.be/3-9oZuX6-Pg
Agree with bullit about voltage drops. It is not necessarily one large drop. It can few smaller ones at different connections. When I had an overcharge issue a number of years ago, three places were the culprit. bulkhead connector, connector along the passenger side valve cover (small block only), and the grounding of the vr case to the firewall.
Removing and installing the vr obviously did something, either the connector on the front or the grounding of the vr. To reduce the chance of VR case ground becoming an issue again I replaced the self tapping screws with small bolts and removed the cowl screen to add star washers and ny-lok nuts to the back side of the firewall. I also spent quite a bit of time cleaning the BH connector. Every time you improved the connection you could see the alt output voltage change from a previous reading.
Quote from: Bullitt- on June 09, 2023, 04:58:29 PM
Do you know how to perform a voltage drop test? I have been searching for a relatable video but most are bench tests with minimal losses. This one focuses on the battery terminal but can be conducted between any two points in a circuit for instance you could put one lead on the + battery terminal and the other to the VR connector with the Blue wire (with ignition in run position) to see how much loss there is total. I believe .5V or less is acceptable. If it's higher you can break it down into smaller segments to see where the problem lies.
https://youtu.be/3-9oZuX6-Pg
Thanks man helpful as always.
I checked the blue wire at the VR as discussed above and I getting about .7. So not to high.
I checked the connections at the temp sensor, bot for the fan and the gauge.
The fan sensor was under .5. The gauge was like 5 volts. That seems high.
I did pull the gage sensor off quickly and fired it up.
Initallyblooked good, under 14volts. But quicly moved up over 15. So thats not it.
Checked the
Well i just checked all the connections under the hood.
Not really sure if this is right. But i disconnected all the bulkhead connections and checked them. Most connectors show full 12 volts. Is that right or should I do it with the connectors on?
I cleaned and checked every connection under the hood, including the battery terminals. Did not help.
The fact that it seemed normal right after you messed with it may be a clue.
I found a video that blamed an overcharging issue on a bad VR plug. I seem to recall using a tiny flat blade inserted between the rubber & metal connector to collapse the connector a tad to tighten it up.
Otherwise I might suspect a poorly crimped connector or wire that's breaking down.
Quote from: 7212Mopar on June 09, 2023, 02:55:23 PM
:veryexcited: Still have plan to replace the stock alternator to accommodate the draw from the electric fans?
@7212Mopar (https://forum.e-bodies.org/mlist/7212mopar_441) yeah that is still my plan. I have the fans and the shroud SO I may as well use them. Just trying to see if I can get this alt to charge at less than 15 volts first.
Quote from: Bullitt- on June 12, 2023, 05:16:59 AM
The fact that it seemed normal right after you messed with it may be a clue.
I found a video that blamed an overcharging issue on a bad VR plug. I seem to recall using a tiny flat blade inserted between the rubber & metal connector to collapse the connector a tad to tighten it up.
Otherwise I might suspect a poorly crimped connector or wire that's breaking down.
I actually rebuilt the VR connectors last year using only a new rubber plug and all new connectors, not that it means much. One of the original wires snaped and caused an overcharging issue. I did pinch the VR connectors last night, no change, still charging at a tick over 15 volts.. I may redo or jump the green wire just to make sure that is not the problem.
With connectors unplugged you will always read battery voltage. Without current flow, there will be no voltage drop.
Due to your reported symptoms, I would concentrate on the vr mounting and the connector and the wires to, and from the vr. I might even run a temp jumper from battery negative to the vr case.
Quote from: dodj on June 15, 2023, 05:51:24 AM
With connectors unplugged you will always read battery voltage. Without current flow, there will be no voltage drop.
Due to your reported symptoms, I would concentrate on the vr mounting and the connector and the wires to, and from the vr. I might even run a temp jumper from battery negative to the vr case.
Thanks
@dodj (https://forum.e-bodies.org/mlist/dodj_816) that is my plan, a jumper on the green wire. I like the additional ground idea, I will try that as well.
Jason
Quote from: Cudajason on June 09, 2023, 04:23:52 PM
Quote from: Bullitt- on June 09, 2023, 03:26:06 PM
I believe that 15+volts is to high. I would charge the battery fully with a battery charger and if the situation continues suspect the new VR is bad or the Blue wire that the VR reads the need has poor connections or degraded wires.
:pullinghair: :pullinghair: :pullinghair:
Never mind. I just put the old VR back on just to see if the new one was bad. With the old one, reading over 16volts!!!!
Maybe to old one is bad???
I will pit the new one back on and check the wires. The wires are all new as I redid that part of the harness last year.
I still suspect the alternator is bad. If internally is fried, it will not properly regulate regardless of VR output signal.
~16 volts is full tilt alt will put out unregulated.
I chased same issues. Bad grounds, low signal voltage, multiple vr's and finally replaced alternator.
What I did to convince myself was start engine. @idle it was 16 volts. I then dogged engine rpm down until it almost stalled. With engine rpm way down, charge voltage never dropped off of 16v.
Borrow the offered one. Once on retest the blue wire voltage with full charged battery to reconfirm signal wire is proper.
Quote from: YellowThumper on June 19, 2023, 11:22:18 AM
If internally is fried, it will not properly regulate regardless of VR output
Well the alt can't regulate... that's why there is a separate regulator......
But if it was fried internally.... it wouldn't work at all. Jason's does.
Jason 'cause of the site's slowness feel free to text me if you want re: my alternator.
John
Okay, no problem. Because of this site's issues I didn't get your post before typing mine. What a clusterf@#$%&! :verymad:
New 130 amp alt came today. Have ti fiddle with the belt adjustment a bit, but its on there.
I hooked it up using the one wire option, which is really two wires because you have to ground it.
Fired up reading 13.9 volts at idle. The gauge shows lots of movement when you rev it up!
I think that is fixed.
Quote from: Cudajason on June 20, 2023, 04:13:33 PM
I think that is fixed.
Sure sounds like it :bigthumb:
Hmm. One wire option. Is the regulator in the alternator?
Quote from: dodj on June 20, 2023, 04:40:49 PM
Hmm. One wire option. Is the regulator in the alternator?
Yes sir, it has what I would call a small external regulator on the alternator.
Jason
So you didn't fix the problem..... you bypassed it. Irrelevant I guess seeing as you are going with a regulated alt.
Just a personal opinion, but one wire alt's aren't as good as the original Mopar alt's
Going to remove the stock vr I would guess?
What do you do with the field wires and the stock regulator? Leave it unconnected.
Quote from: dodj on June 21, 2023, 01:52:17 PM
So you didn't fix the problem..... you bypassed it. Irrelevant I guess seeing as you are going with a regulated alt.
Just a personal opinion, but one wire alt's aren't as good as the original Mopar alt's
Going to remove the stock vr I would guess?
You could look at it that way, but it sure seems to be fixed.
Took it for a spin on the weekend, with the eclectic fans installed and had no issue.
Quote from: 7212Mopar on June 22, 2023, 10:08:37 AM
What do you do with the field wires and the stock regulator? Leave it unconnected.
Yep just disconnect it and tape off the connectors. I will likely dig into the wiring harness, which is not stock, I built it myself, and pull out those wires and remove the VR.
Quote from: Cudajason on June 26, 2023, 08:16:37 AM
Quote from: dodj on June 21, 2023, 01:52:17 PM
So you didn't fix the problem..... you bypassed it. Irrelevant I guess seeing as you are going with a regulated alt.
Just a personal opinion, but one wire alt's aren't as good as the original Mopar alt's
Going to remove the stock vr I would guess?
You could look at it that way, but it sure seems to be fixed.
Hi Jason, I didn't mean to say that you didn't repair the charging system, obviously did. Just that the problem with the vr and wires was never quite determined..... it was made redundant. ...... and I was left hanging waiting to hear what the root cause of your issue was.... now I'll never know! :'(