65amp wiring/trouble shooting
- Thread starter SlantedMark4
- Start date
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I've replaced the switch already but didn't check the connector... So you think it was the light switch connector that propably
started melting?
slantsixdan
=..=
Just a possibility. If it was really bad you probably would have noticed. If you have the old switch look at the terminals to see if they have sighns of overheating. If so, then might be worth checking the connector. With relays off of the alternator, then its not so important. I got away with a damaged connector for years that way.
Thanks mate. Imma gonna read it later. It's 1am here and I can't even see the letters anymore lol
Good I have to make dinner!
Maybe tommorrow you can take some more photos of the engine bay. 1974 models can have some extra electrical stuff for safety and emissions - at least the ones sold in the US (maybe Canada too).
Maybe tommorrow you can take some more photos of the engine bay. 1974 models can have some extra electrical stuff for safety and emissions - at least the ones sold in the US (maybe Canada too).
Okay interesting. I've lots of time tomorrow to fix this bi***
Thank you alot man and have a nice dinner!
67Dart273
Well-Known Member
Which part? The run line branches off. The blue alernator field wire is one of the branches. What I was speaking of, the relay, you want to break the "run" soon after it comes out of the bulkhead before it branches off
67Dart273
Well-Known Member
Mattox the big wires through the separate grommet are known as "fleet taxi police" wiring and are used with factory optional 65A alternator. OP that wiring IS IN FACT a partial "bypass" from the factory and bypasses most of the current around the bulkhead connector. You are lucky, few of these girls have that setup.
That setup is not well documented in the 74 manual as the wiring diagrams are rather AFU.
That setup is not well documented in the 74 manual as the wiring diagrams are rather AFU.
Yes. The book diagrams are not that clear on these options. We'll have to figure out what is actually on Mark's car.
Post 1. Back of ammeter photos show two wires at the black wire junction.
According to the shop manual, there should be three with 60 amp alternator and the rear window defroster grid.
Side note. Looks like the insulation is cracked and the connections are not exactly clean. Next time in there ( with the battery disconnected, remove clean, and reinstall.) Unless you see serious damage, a dab of liquid electrical tape should close up the insulation damage.
Post 18. First photo shows 3 wires battery wires at relay junction.
One is from the battery.
Can you see where the second red wire goes? or does it gointo the wrapped harness?
The diagrams show the fuseable link is the line going to the ammeter through the grommet.
Does this fusible link connect to a red wire going to the grommet. If not, where does it go?
(it would be a good idea to clean these connections too. again disconnect the battery first.)
Same post, photos show a heavy red wire coming out of the harness with a round white connector.
Where does it connect to? A fusible link?
Finally there are two black wires coming out of the grommet.
One comes from the alternator output.
What does the other connect to?
This is the diagram so far.
With the questions above answered and some more photos probably can figure it out.
Explanation of the wire codes.
A is Battery related. A1 is a branch and A1A is the first segment. 10 R is 10 gage Red insulation.
R is alternator related. R6 is alternator output. R3 is control of the rotor power.
J is Ignition related, although by 1974 that includes the feed into the key switch, power to alternator, and the electric choke.
J1 is power to key switch, J2 is run.
Post 1. Back of ammeter photos show two wires at the black wire junction.
According to the shop manual, there should be three with 60 amp alternator and the rear window defroster grid.
Side note. Looks like the insulation is cracked and the connections are not exactly clean. Next time in there ( with the battery disconnected, remove clean, and reinstall.) Unless you see serious damage, a dab of liquid electrical tape should close up the insulation damage.
Post 18. First photo shows 3 wires battery wires at relay junction.
One is from the battery.
Can you see where the second red wire goes? or does it gointo the wrapped harness?
The diagrams show the fuseable link is the line going to the ammeter through the grommet.
Does this fusible link connect to a red wire going to the grommet. If not, where does it go?
(it would be a good idea to clean these connections too. again disconnect the battery first.)
Same post, photos show a heavy red wire coming out of the harness with a round white connector.
Where does it connect to? A fusible link?
Finally there are two black wires coming out of the grommet.
One comes from the alternator output.
What does the other connect to?
This is the diagram so far.
With the questions above answered and some more photos probably can figure it out.
Explanation of the wire codes.
A is Battery related. A1 is a branch and A1A is the first segment. 10 R is 10 gage Red insulation.
R is alternator related. R6 is alternator output. R3 is control of the rotor power.
J is Ignition related, although by 1974 that includes the feed into the key switch, power to alternator, and the electric choke.
J1 is power to key switch, J2 is run.
Okay you asked here some things
The red wire you asked if it is connected to a fusible link, yes is does. The wire goes from the starter relay into the harness, then it goes into the white connector. Then, it continues as a black or smth wire to a fusible link which ends in the bulkhead connector (you can actually see it between left and middle connector on the bulkhead).
To the two black wires coming out the grommet. They merge into a single thick brown cable that goes right on top of the alternator.
It looks like there's a 4th wire going into the grommet, but it is actually the thick brown cable going to the bracked next to the grommet.
A little more information about "the red wire you asked about." From the factory service manual, starting from the B post on the starter relay - A1B 10R connects to fusible link A1C 16DBL which enters into bulkhead connector J. Then color changes to red A1 D12R on dash side of firewall which is capped off near ammeter. This wire is capped off because its not used with the 60 amp option.
If you see more in the service manual that may cover the two black wires through the grommet, please post.
Because that part of the scheme is not shown (at least in the diagrams I was looking at) I wanted to leave open the possibility that the standard A1B was not reused for some other purpose.
It's possible they are spliced into a junction.
It seems likely this a segment from the standard wiring (as townsend wrote) and is no longer used for any circuits.
Lemme look at your photos next
It appears your car has a Seatbelt interlock system.
That is what the box is on the firewall.
There should be an over ride button in case you need to bypass it to start the engine.
Brown 1 powers the the starter solenoid with the key in start. Same as a cars without the interlock.
That is what the box is on the firewall.
There should be an over ride button in case you need to bypass it to start the engine.
Brown 1 powers the the starter solenoid with the key in start. Same as a cars without the interlock.
This is my best guess so far.
A Chrysler fuseable link that was black IIRC is 12 gage. That would protect the 8 gage wires. In theory anyway.
In which case I'm surprised there is not a 16 gage fusible link protecting the 12 gage wires.
At least visually, the multiconnector on the fire wall looks good in the photos.
Other connection that often develop resistance over time are:
Column connector - especially the J1 power feed in it. But also check J2.
Engine harness connector.
At least do a visual check on them first.
Then since everything is running. Maybe the next best step is to do a test for voltage drop between the alternator and the regulator.
Same as described earlier in the thread.
With the engine running, note at the same time:
How much the battery is charging (ammeter reading)
Voltage at the alternator output
Voltage at the blue field wire if safely accessible
Voltage at the engine harness connector if it can be back probed
Voltage at blue wire at ballast resistor
Voltage at the battery.
Once the battery is recharged (ammeter needle straight up) repeat the measurements.
Then put a non-battery load on it, such as the headlights and heater fan, and repeat the measurements
Votlage should be the same at all points measured. If there is a voltage difference it will be due to resistance and be larger with loads. The problem will be along the current path from the alternator to the regulator.
A small difference under heavy load (like recharging the battery, or lights and heater fan on at the same time) is OK.
However your cars 65 amp wiring was intended to minimize that. The battery should never be subject to more than 15 Volts or it will cook itself.
A Chrysler fuseable link that was black IIRC is 12 gage. That would protect the 8 gage wires. In theory anyway.
In which case I'm surprised there is not a 16 gage fusible link protecting the 12 gage wires.
At least visually, the multiconnector on the fire wall looks good in the photos.
Other connection that often develop resistance over time are:
Column connector - especially the J1 power feed in it. But also check J2.
Engine harness connector.
At least do a visual check on them first.
Then since everything is running. Maybe the next best step is to do a test for voltage drop between the alternator and the regulator.
Same as described earlier in the thread.
With the engine running, note at the same time:
How much the battery is charging (ammeter reading)
Voltage at the alternator output
Voltage at the blue field wire if safely accessible
Voltage at the engine harness connector if it can be back probed
Voltage at blue wire at ballast resistor
Voltage at the battery.
Once the battery is recharged (ammeter needle straight up) repeat the measurements.
Then put a non-battery load on it, such as the headlights and heater fan, and repeat the measurements
Votlage should be the same at all points measured. If there is a voltage difference it will be due to resistance and be larger with loads. The problem will be along the current path from the alternator to the regulator.
A small difference under heavy load (like recharging the battery, or lights and heater fan on at the same time) is OK.
However your cars 65 amp wiring was intended to minimize that. The battery should never be subject to more than 15 Volts or it will cook itself.
Last edited:
67Dart273
Well-Known Member
Overvoltage is almost always easy
1...Can be shorted brush holder in the alternator causing it to "full field." This will have to be on the green wire connection, OR a short in the green to ground, which has happened
2...Poorly grounded VR or ungrounded VR,
3...Bad VR
4...Drop in the ignition circuit, which powers the VR and thus causes it to "think" the battery is low, and ramp up charge
HOW TO FIND
A...Turn key to 'run', engine stopped. Hook one lead of multimeter to "run" buss as close as you can get to VR WITHOUT disconnecting anything. The ballast or the blue alternator field wire. Stab remaining meter lead into the battery POS post. You should read very little, the less the better. Over .3V (3/10 of 1 volt) you need to investigate drop in the "run" circuit
Above is where adding an ignition relay comes in, as I've mentioned before
B....Can be in VR ground circuit. Run engine to warm, normalize battery. With engine running on fast idle to simulate low to medium cruise RPM, stab one probe of meter into battery NEG post, and stab other into VR mounting flange. Be sure to get through chrome, paint, rust. As above, you hope to read very little, zero is perfect.
A good way to improve battery-to-body ground is to run a jumper from an unused hole on the rear of the driver side head to the firewall, such as the master cylinder mount studs. But a "Ford style" starter cable, AKA eyelet to eyelet about a foot, foot and a half long
5...Shorted brush. The green VR wire controls "the amount of ground" so to say on the field, which is supplied switched 12V on the blue wire. Pull the field wires, check each to the case for continuity. They should be open/ infinity.
6...If none of this fixes the problem, replace the VR. WHILE DOING SO, check the VR connector for good connection. I got "waylayed" as I was going to try this but I THINK a .177 caliber rifle cleaning brush will enter those connector terminals.
1...Can be shorted brush holder in the alternator causing it to "full field." This will have to be on the green wire connection, OR a short in the green to ground, which has happened
2...Poorly grounded VR or ungrounded VR,
3...Bad VR
4...Drop in the ignition circuit, which powers the VR and thus causes it to "think" the battery is low, and ramp up charge
HOW TO FIND
A...Turn key to 'run', engine stopped. Hook one lead of multimeter to "run" buss as close as you can get to VR WITHOUT disconnecting anything. The ballast or the blue alternator field wire. Stab remaining meter lead into the battery POS post. You should read very little, the less the better. Over .3V (3/10 of 1 volt) you need to investigate drop in the "run" circuit
Above is where adding an ignition relay comes in, as I've mentioned before
B....Can be in VR ground circuit. Run engine to warm, normalize battery. With engine running on fast idle to simulate low to medium cruise RPM, stab one probe of meter into battery NEG post, and stab other into VR mounting flange. Be sure to get through chrome, paint, rust. As above, you hope to read very little, zero is perfect.
A good way to improve battery-to-body ground is to run a jumper from an unused hole on the rear of the driver side head to the firewall, such as the master cylinder mount studs. But a "Ford style" starter cable, AKA eyelet to eyelet about a foot, foot and a half long
5...Shorted brush. The green VR wire controls "the amount of ground" so to say on the field, which is supplied switched 12V on the blue wire. Pull the field wires, check each to the case for continuity. They should be open/ infinity.
6...If none of this fixes the problem, replace the VR. WHILE DOING SO, check the VR connector for good connection. I got "waylayed" as I was going to try this but I THINK a .177 caliber rifle cleaning brush will enter those connector terminals.
I've already put in a new VR and the new battery isn't overcharging, but I still need to check all those things you've talked about here I guess.
And that might have been it.
But yes check things out.
Make sure the green wire from the alternator to the regulator is not accidentally getting grounded to the chassis or engine.
Look at the connectors mentioned before.
Then do a running check of the voltage is being regulated.
The ammeter only shows whether electrons are moving in or out of the battery.
Test whether the voltage stays in the acceptable range when there are other loads and when the rpm is increased.
I think you mentioned someone had a multi-meter so take advantage of that and make sure there will be no problems when driving that could have been avoided. The battery is just one of many items that will draw more current when power is at higher voltage. That can cause lights to burn out, circuit breakers, and fuses to open, etc.
If the output voltage of the alternator stays below 15 even when lights and other items are turned on, and engine speed is increased to 1200 or 1500 rpm, then everything is working.
Regulator part number from the 1973 parts Catalog shows it was used for all Chrysler alternators that year.
So your replacement is probably fine for the application. At least as fine as replacement parts are these days.
The 65 amp L/C listed in that book is a Leece Neville alternator, and thats why it gets a different regulator.
I don't quite understand. The original VR in my car I had to replace has the parts number 3438 150, just like the one on top. But the 65amp had a different VR?
The replacement is an SMP VR125.
That is correct. The part number of the regulator you removed was in 1973 parts book as used for all Chrysler alternators.
The '65 amp L/N' alternator listed in the '73 parts book was not made by Chrysler, but by Leece Neville and has slightly different wiring.
I took look at Hamtramck Historical's Library, and the '74 sales books list the alternator with defogger as '65 amp' like you found.
See page 15 The 1970 Hamtramck Registry - 1974 Dodge Dealership Data Book - Dart
It's a confusing naming convention and its not standardized.
If your car's alternator is original, the '74 Service Manual shows
Those tags made it easier than looking upo the part numbers.
Note these ratings are just names. They very roughly indicate the maximum that they can provide.
For normal driving, they only need to keep the car running, which is around 5 to 7 amps for your car.
With headlights, wipers, heater fan on, the demand will be closer to 30 amps.
The electric rear defroster draws alot of current just by itself, that's why your car got the optional alternator, heavy battery, and wiring modifications.
I went to my car cuz I was wondering if I could find something and I've found this. The part number is 3438713 and the black dot is an indication for the 65amp I guess.
That's just the casting part number.
The black over the Date wheel may be an inspector's mark.
if it hasn't been sandblasted by a rebuilder, the casting year is in the center of the circle.
From what I can see in the photo from yesterday, everything looks like it could be original except for the black wire and device on the output stud.
If the tag is still there, it will be under the head of an assembly screw.
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