Alternator question

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4spdragtop said:
Del when it happened it was on the highway both times. So I'm not sure. Kinda panic mode with cars all around lol.
I wanted to get it fired up and "wait" for it to die and investigate.
To test alt, should I remove field wire from alt or battery wire?
I will look into the bulkhead connectors.
I did the Mad bypass, but I can't remember if I got "rid" of the welded splice?
Thanks Del, square peg round hole with me and electrical...better grab a bigger hammer lol.
Click to expand...

I would not even worry about the alternator/ regulator for now. Again, it sounds like something lost contact and you lost power. Do the "wiggle test" etc. Since you did the MAD thing, I'd start with the ammeter wire connections. Heck Steve it could even be a battery cable / connection
 
Ok spent time under the hood and dash. Ammeter bypass connection under dash is good.
Bulkhead connectors good. 2 out of the 3 plugs are MH in great shape.
I am going to remove unnecessary wires(ac compressor, oil psi sender, coolant temp). These are all factory wires and I have Aurometer gauges, so it helps clean up engine bay.
No spark from plug wire, no spark from coil. Both done by crossing starter relay and key on.
Measured coil resistance. Primary 1.6 ohms.
2ndary 9.040K ohms.
Coil wire 3900 ohms.
These seem within spec?
Here is pic of coil.
What's with the specifics on wire/resistance?
Break time lol
Thanks
Steve

20180827_153621.jpg
 
Ya' probably went through this but...…………
upload_2018-8-27_14-49-44.png
upload_2018-8-27_14-52-27.png


Check that plug connector for the distributor as well.
 
Step back, Steve.............LOL

What "doesn't work?"

1....Do you have lights, nice and bright? Head lights, dash lights, tail and park? Wiggle connectors, bulkhead, up in ammeter wire connections, etc anything dim? or intermittent?

2....Key on, measure coil voltage.........at the "key" side of ballast you should have "close to battery" with key in run. Wiggle test again........bulkhead connector, battery cables, ignition switch connector.................

3...It won't crank? OK you can jumper it.................but if there's no voltage at ballast, coil, that is "ahead of" yourself

You want to call, shoot me a PM
 
Thanks guys, sorry I wasn't able to get as much accomplished as I was hoping.
Here is more info.
Key on, no volts to either post on coil(used test light for test)
I have headlights, LOTS of cranking power. Battery new last year.
I checked for continuity at ECU plug to there ends and all was good.
Batt ground to vr case good.
Batt ground to ecu case good.
I'm sure I did more gotta scratch my head.
I'll get to more investigating tomorrow.
Thanks guys.
Coil #'s for resistance good?
Coil wire good?(no continuity) 3900 ohms resistance?
Daves69 said:
Ya' probably went through this but...…………
View attachment 1715216420View attachment 1715216421

Check that plug connector for the distributor as well.
Click to expand...

Murray said:
After break- do we have juice at the coil with key on?
Click to expand...

67Dart273 said:
Step back, Steve.............LOL

What "doesn't work?"

1....Do you have lights, nice and bright? Head lights, dash lights, tail and park? Wiggle connectors, bulkhead, up in ammeter wire connections, etc anything dim? or intermittent?

2....Key on, measure coil voltage.........at the "key" side of ballast you should have "close to battery" with key in run. Wiggle test again........bulkhead connector, battery cables, ignition switch connector.................

3...It won't crank? OK you can jumper it.................but if there's no voltage at ballast, coil, that is "ahead of" yourself

You want to call, shoot me a PM
Click to expand...
 
Well, there is the problem- no juice to the coil. Why? Ballast resistor? Switch? Keep backing up on the ignition circuit until you find the problem.
 
Steve, I just disconnect the ballast both terminals and the ECU plug.
I'm looking for 12 volts on the Ign 2 ballast connector in "start" key position and 0 volts in "run".
The other connector should have 12 volts in "run" and "0" in start.
I believe your test light (not continuity tester light) should have lit for you in either key position on the + side of the coil. So evidently you got notta getting to the coil.
Check the ignition switch connector too.
My open came back to the bulkhead connector. It's probably easier for you to check yours as things get a bit snug back there for me.
IMGP0189.JPG
 
Heres some more "stuff".
This is with everything hooked up.
Key on, 1.4v to coil +ve.
Key on, 5.6v to cool -ve
Tested "key" side of ballast(blue ign wire and blue w/tracer), got 9.4V(should it be 12v??)
I ohmd the ballast resistor(unplugged) and get 2 ohms.
Just got off midnight shift, I know I forgot some tests. Try to get to them soon.
Thanks all.
Oh lights on, bright hazards and tails all work good BUT, it took a second or 2 for them to "start" if that makes sense?
I also noticed there is no ground strap from engine to firewall. I bought one and would like to mount, where is factory location?
Thanks all, much appreciated.
 
Been working so finally found time today.
Heres some tests I performed, working by myself so all cranking tests were done with key "on" and crossed at starter relay. If that makes a difference?
Tests.
Key on ballast unhooked, 10.69 V at light blue wire with yellow tracer.
#2 key on coil +ve 5.75V
#3 key on coil-ve 1.4V

#4 cranking from coil tower 3.6 mV
#5 swapped coil and same test as 4. 5.3mV
#4 and #5 produced no spark obviously.
Could it be distributor pickup?
Thanks again all.
 
The light blue is that your alternator field wire? If so that is WAY LOW

Ignition "run" power comes out of the bulkhead and branches off to feed the VR the ignition, the alternator field, and if equipped, electric choke, and maybe some smog doo-dads

THAT POINT should be very close to "same as battery" with key in "run" position.

So hook everything up. Without unhooking ANYTHING probe both sides of the ballast and see what is HIGHEST and post that here. Check that reading against the battery. IE if the battery is 12.6, that point of test should be VERY close, maybe 12

If lower, you have a problem in the path from battery getting to the ignition switch, and the "ignition run" wire coming back out through the bulkhead.

With the key in run, measure coil PLUS and coil NEG. PLUS should be 6V--10V or so, this varies with the coil type. Coil NEG should be real low perhaps 1V

Try jumpering a clip from battery to coil PLUS and see if it starts, fires, or at least has spark.
 
Thanks Del, the light blue wire with yellow tracer is is same as diagram below. Measured at ballast end and had 10.69V
Key on coil +ve 5.75V
Key on coil-ve 1.4V

The ballast HIGH side test? Should I do that with key in run?
Oh i took distributor out and gave it a "spin test", and it "beeped" with meter in "continuity" mode, so that's good.
I'll get back at it tomorrow.
I'm contemplating buying another VR as a spare anyway, but before I pull trigger with that, should I go the square back alternator route with newer style VR?
Is it that much of a benefit to do so?

67Dart273 said:
The light blue is that your alternator field wire? If so that is WAY LOW

Ignition "run" power comes out of the bulkhead and branches off to feed the VR the ignition, the alternator field, and if equipped, electric choke, and maybe some smog doo-dads

THAT POINT should be very close to "same as battery" with key in "run" position.

So hook everything up. Without unhooking ANYTHING probe both sides of the ballast and see what is HIGHEST and post that here. Check that reading against the battery. IE if the battery is 12.6, that point of test should be VERY close, maybe 12

If lower, you have a problem in the path from battery getting to the ignition switch, and the "ignition run" wire coming back out through the bulkhead.

With the key in run, measure coil PLUS and coil NEG. PLUS should be 6V--10V or so, this varies with the coil type. Coil NEG should be real low perhaps 1V

Try jumpering a clip from battery to coil PLUS and see if it starts, fires, or at least has spark.
Click to expand...

ecudia.jpg
 
I would get it running before worrying about the VR. It might not be the charging problem and normally won't prevent the car from running

The 10.xx is way way low. What does the battery measure, IE is it dead?
 
I threw a battery charger on it today. It was getting a little low. I.load tested it a few days ago and it came up good.
Battery was 12.5
I'll redo those tests tomorrow and post results.
I have another used orange box ecu from my old 84 dodge D150 that I can use. Unsure of its condition, gonna order one from dealership tomorrow. I think they're only around $35
Thanks again Del!
67Dart273 said:
I would get it running before worrying about the VR. It might not be the charging problem and normally won't prevent the car from running

The 10.xx is way way low. What does the battery measure, IE is it dead?
Click to expand...
 
4spdragtop said:
I also noticed there is no ground strap from engine to firewall. I bought one and would like to mount, where is factory location?
Click to expand...

Lol, I have mine from a hole in the head (pun intended, bolt hole right head) to a heater blower motor stud.

Don't forget to check continuity at the plug connectors (ECU, dist.) and grounds.
 
Ok so made time today. I had a spare coil hooked up, laying on top of 1st one. I noticed the spare was leaking some oil.
Did ohm test on both coils. Leaky one primary was 1.4 ohms. 2ndary was 8900 ohms. Checked 1st initial coil, 1.6 ohms primary. 2ndary 8650 ohms.
Hooked initial one back up.
Static batt voltage 13.1 V
Swapped spare used ecu from 84 D150.
Fired right up.
Battery volt at idle 13.5v
Alternator stud to ground 13.8v.
I realize I didnt run all your tests del. Ran outta time today. I will get more results.
I rev in park voltmeter climbs to 15V and drops with rpms.
67Dart273 said:
I would get it running before worrying about the VR. It might not be the charging problem and normally won't prevent the car from running

The 10.xx is way way low. What does the battery measure, IE is it dead?
Click to expand...
 
4spdragtop said:
I rev in park voltmeter climbs to 15V and drops with rpms.
Click to expand...

You very likely are suffering what I touched on before.........voltage drop in the path from battery, through bulkhead/ key/ connectors and back out to the ignition.
 
Thanks Del, still a fair amount of underhood tidying to do, so will check connections tomorrow.
The voltmeter dropping to 13v is normal correct? And 15 at high rpm?

67Dart273 said:
You very likely are suffering what I touched on before.........voltage drop in the path from battery, through bulkhead/ key/ connectors and back out to the ignition.
Click to expand...
 
Ok so spent some time under hood tidying up wires. Removed 12v choke wire from ballast resistor. Removed choke last year.
Started car up, battery 12.73 Volts, 12.6V alt stud to ground.
Shut car off, general underhood tidy up, go to start car, cranks but no start, as soon as I let key to run position it fires, and is running. Weird? So shut car off and restart.
Same result if it makes sense, "turn to start", it cranks but just cranks. As soon as I let key return to "run" position it fires up and stays running/idling.
But volt gauge now reads 11V.
Battery voltage 12.5V
ECU case to batt.+ve 12.4V
Rev car up in park, voltmeter now only rises to 12.1V. Before it was revving up.to 15V and dropped as rpm dropped.
I dont trust to take the car for a run as I dont have good known spare VR Ecu etc.
Suggestions?
Thanks all.
67Dart273 said:
You very likely are suffering what I touched on before.........voltage drop in the path from battery, through bulkhead/ key/ connectors and back out to the ignition.
Click to expand...
 
Any ECU recommendations? I called dealer and can no longer get the Orange box P4120505. Should have bought a couple last year when I got last one dammit.
I also have to order a VR and coil to have as "good known spares"
Recommendations for these as well?
Thanks
Steve
 
Any ECU recommendations? I called dealer and can no longer get the Orange box P4120505. Should have bought a couple last year when I got last one dammit.
I also have to order a VR and coil to have as "good known spares"
Recommendations for these as well?
Thanks
Steve
 
Still not right. Starts after releasing key from "start" position. Turns over in "start" but wont fire.
Heres tests while it was running.
12.83 Batt V
Alternator batt stud to ground 13.4V (bounces) at idle.
10.67V at VR FLD a idle. Volts go up with rpm.
Alternator batt stud to ALT case 14.14V
Above tests were done with it running.
More tests
Key off. 12.75 Batt voltage
Alternator batt stud to batt -ve 12.72V
Key on vehicle off
VR IGN to ground 10.4V
VR FLD to ground 9.53V
FLD terminal on alternator(again 1 wire alt) to ground 12.03V
I bought a Reman square back alt(used 73 340 Duster for application).
I also have a new BWD coil(again 73 application).
2 cheap ECUS are on their way. I'm prepared to buy better ones if recommended or once I figure out what the.problem is??
Also replaced pickup coil in distributor as one wire bared.
Suggestions?
Thanks
Steve

20180916_170208.jpg


20180912_123932.jpg


20180916_105732.jpg
 
I believe that "yellow" wire in the post #38 diagram should have full battery voltage in the key "start" position ONLY which powers the coil on cranking startup.
In the key "on" position, the "blue" provides the coil with power through the ballast.
In what I read from your post #48, the coil must be seeing power as you allow the key to rotate back to the run (ign 1) position for the engine to catch and stay running.
I'd think I'd trace the "yellow"(ign 2 in post #28) back from ballast Steve.

How I check...…

1) Disconnect both sides of the ballast.
2) Disconnect the ECU plug.
3) Attach volt meter to Ign 2 ballast plug and ground.
Zero volts in "key off" position.
Battery voltage in "key start" position.
Zero volts in "key on" position.

4) Attach volt meter to Ign 1 ballast plug and ground.
Zero volts in "key off" position.
Zero volts in "key start" position.
Battery voltage in "key on" position.
 
Thanks Dave, time for a break again lol. Beyond frustrated, appreciate the help.
Daves69 said:
I believe that "yellow" wire in the post #38 diagram should have full battery voltage in the key "start" position ONLY which powers the coil on cranking startup.
In the key "on" position, the "blue" provides the coil with power through the ballast.
In what I read from your post #48, the coil must be seeing power as you allow the key to rotate back to the run (ign 1) position for the engine to catch and stay running.
I'd think I'd trace the "yellow"(ign 2 in post #28) back from ballast Steve.

How I check...…

1) Disconnect both sides of the ballast.
2) Disconnect the ECU plug.
3) Attach volt meter to Ign 2 ballast plug and ground.
Zero volts in "key off" position.
Battery voltage in "key start" position.
Zero volts in "key on" position.

4) Attach volt meter to Ign 1 ballast plug and ground.
Zero volts in "key off" position.
Zero volts in "key start" position.
Battery voltage in "key on" position.
Click to expand...
 
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