The photo you showed of the ballast is correct. What I was afraid of , is that maybe the wire colors were bleached out on your VR plug and you might have them switched. As long as you can ID the blue, should be good
Overcharging, 2 fld alternator question
- Thread starter 4spdragtop
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Vaanth
Well-Known Member
Correct, the blue with yellow tracer from the ECU plug ties into the Ignition RUN, or Ignition 1, wiring.
4spdragtop
Well-Known Member
Thanks guys, no Del it's not bleached out, it's brand new.
I wasn't sure if I should have tied the blue/yellow ecu wire into the other wire(solid blue) on the ign 1 side.
I was "hoping" it was wired wrong and would explain the V drop. I'll get this part rewired and get bucket seat pulled out to crawl under dash.
Seeing as how it's Mad bypass, I'm assuming follow the large red and blk wires in thru firewall, and leading to ign switch?
Same goes for blue w/tracer from ballast thru bh connector(N bh cavity)
Thanks guys
I wasn't sure if I should have tied the blue/yellow ecu wire into the other wire(solid blue) on the ign 1 side.
I was "hoping" it was wired wrong and would explain the V drop. I'll get this part rewired and get bucket seat pulled out to crawl under dash.
Seeing as how it's Mad bypass, I'm assuming follow the large red and blk wires in thru firewall, and leading to ign switch?
Same goes for blue w/tracer from ballast thru bh connector(N bh cavity)
Thanks guys
4spdragtop
Well-Known Member
So i replaced the VR plug/pigtail, as well as both blue and green wires to alternator. I was hoping "this" would fix issue....nope.
I get 1.4V at ign1 and batt +ve with key on not running.
Any other checks underhood before I pull seat and lay under dash?
Thanks
Steve
I get 1.4V at ign1 and batt +ve with key on not running.
Any other checks underhood before I pull seat and lay under dash?
Thanks
Steve
Steve, have you removed the blue wire from the alternator and run a jumper from the terminal on the alternator to battery positive?
Does the alternator still over charge?
Does the alternator still over charge?
4spdragtop
Well-Known Member
Thanks Dana no jumper, and i haven't started it in over a week due to overcharging and rewiring the VR pigtail. I will start it tonight after work and see what "happens"
Basically you are going to have to "chase" every terminal, connector, switch, wire in the "path" from the battery to the VR. The biggest culprits, in no particular order, assuming they are all still in the car, are the buikhead connector for the RED wire, and the BLUE ign "run" wire, the ammeter connections, including the joint between the wire ends and the wire itself, the ignition switch connector terminals and the contacts in the key itself.
It may very well be right in the switch contacts of the ignition switch. I don't know how you'd fix that, other than below, a relay. You cannot buy quality replacement switches anywhere that I know of.
I've posted before Steve, one way around this is to add a relay to run the "ignition run" loads. Electrically, you cut the dark blue "run" wire coming out of the bulkhead into the engine bay, before it has a chance to split off. Run the bulkhead end of that wire to trigger a relay. Feed the relay contacts with about a no12 from the starter relay "big stud" and fuse or breaker protect it, say, 20A
Reconnect the engine bay end of the cut "run" wire to the switched contact of the relay. This will provide a short "no drop" path from the batt to the VR
A second way you could do this is to simply power ONLY the VR from a relay. This will avoid cutting so much into the harness. To do that...........don't cut the blue "run" wire but rather splice into it. With a ballast or ballast terminals present, you can branch a new wire off the ballast "key switch" side. Feed that to trigger a relay, and again, feed the relay power to the contacts off a fused wire off the start relay. Now cut loose the VR blue wire and run that over to the relay switched terminals, leaving the rest of the harness intact.
4spdragtop
Well-Known Member
Thanks Del, just prior to reading your post I fired car back up and measured output on alternator and it's 15V, no accessories on.
Do the blue wire bypass and report back
following...
Following.
4spdragtop
Well-Known Member
So checked running V, and it's 15V, that's at alt stud to batt -ve. Unplugged VR and it now measures 12.8V.
4spdragtop
Well-Known Member
Checked again wiggling key switch, no change, 15V. Turned headlights on brought down to 14.2V, then 4 ways and dropped a little more to 14(ish). Everything off but car running and back to 15 V.
4spdragtop
Well-Known Member
Unplugged blue alt wire and ran jumper from alt **dbl edit** field terminal to batt +ve and still over charging, 14.9V and climbing.
Sorry for stupid question, what does this test show? That issue is alternator?
When I jumper the blue am I bypassing the VR?
Sorry for stupid question, what does this test show? That issue is alternator?
When I jumper the blue am I bypassing the VR?
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4spdragtop
Well-Known Member
Should the jumper go from fld terminal to batt +ve? Or alt stud to batt +ve
Dana I think you are on the wrong track with that. If the VR is seeing V drop through the harness, jumpering battery to the blue field terminal I doubt will prove anythng.
Steve can you access wherever you connected your original original ballast/ keyswitch blue run wire AKA splced that to the MSD small red? If so try leaving the key off, and run the engine with a jumper from the batt (such as start relay large stud) to that blue splice
I still say the easy way, at this point, is to add a relay in that circuit as I detailed earlier.
Steve remember that there is ONLY ONE switched power source under the hood, and that is the blue "run" circuit from the key. Any other power wire that is switched in "run" comes from that wire. The original wire to the ballast, to the blue VR, or the blue to the alternator field comes from that blue "run" circuit.
You have an isolated field alt. The Blue wire provides 12v to one field terminal. The green provides a variable ground from the VR.
the test bypasses the cars electrical system specifically this path...
battery to starter relay lug stud
to fusible link
to bulkhead
To ammeter
To main splice
To ignition switch
to bulkhead
to ballast resister and alternator.
I read 67dart273s comment and yep I missed the target.
The power to the VR needs to be bypassed too, to eliminate the cars wiring.
All of that path could cause a voltage drop.
By going from battery to terminal on alt you eliminated any posable voltage drop.
Since you are still over charging the issue must be the alt or the VR or grounds
OR.... Your volt meter is not reading correctly
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You did it correctly.
That's a good point.
4spdragtop
Well-Known Member
OK, so no luck tracking down voltage drop. I removed bucket seat and ac diffuser. Swapped ign switch, wiggled all the connections and no change, still 1V drop. I had lori watch the meter while I was under dash wiggling.
I wired in a 4 blade relay.
I still show the 1V drop from batt +ve to ign 1 at ballast, key on not running. Fired car up and measured from alt stud to batt -ve. 14.6 at idle increase rpm and increases to well over 15 pushing 16V.???
I wired in a 4 blade relay.
I still show the 1V drop from batt +ve to ign 1 at ballast, key on not running. Fired car up and measured from alt stud to batt -ve. 14.6 at idle increase rpm and increases to well over 15 pushing 16V.???
Key on you have a load from the electronic ignition OR points if closed.
That could account for 1v drop what does your alt meter show with the key on.
Of course you do. That should NOT cause a drop as such. Maybe a few tenths.
Steve I'm running out of ideas. You may have to drum up a local guy to help you. There has GOT to be a drop in that path to the VR IGN terminal. Whatever terminals, crimps, ANY connections. IS IT POSSIBLE that when you wired part of that up you, "let's say" stripped a wire and ended up with a bunch of strands cut? In other words, you turned a no.16 wire into a no.20 wire in effect?
Maybe it would be easier to measure to ground. DRAW OUT the path from the battery to the VR. If you have the relay properly connected, the path will be battery---start relay big stud---your new wire to the relay 30 terminal, from the 87 terminal to where you spliced to the blue wire, then to the ballast, and you may have to untape to find where it splices to the wiring to the VR.
You can either measure to battery plus or to ground, but measure EACH POINT on the path to the VR. If the relay is correct, there isn't that much there. And there isn't much wire length, either.
Where you cut the blue to installl the relay, is that wire nice clean shiny copper, or is it blackish and oxidized?
IF YOU HAVE the relay wired correctly, the key stuff under the dash should not have an effect on the VR at this point. That is the entire purpose of the relay.
Yes but with bad connections, old wire, old switches add another 0.5v drop.
I got a 0.4v drop at the battery just having points closed. (VR disconnected)
With engine running i get about 6 volts to the field and 13.7v at the battery
Steve, what voltage are you getting on the green wire to battery negative with the engine running
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