Reread his last paragraph carefully. This isn't about fuses in general, its about a protective device on the battery feed (or feeds).
Fusible Links in Charging System
Bypassing the Amp gauge - Question about the MAD Electrical method
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Fusible Links in Charging System
Xtreamist
Well-Known Member
Doesn't the two fusible links protect or am I missing something? Are you suggesting the huge feed from the battery needs a fuse?
You got it. Whatever design you have, it needs to be protected from the battery. The starter is the exception.
The weakness of the MAD's idea is that it sends all the power through two fusible links.
What you need to do is
(1) trace the alternator feed. It should go to the main splice. That's the simplest and the best for basic electric (no efi or electric fuel pumps etc). Depending on your wiring skills and the condition of the bulkhead connector should determine whether you want to run an additional wire in parallel through a grommet.
(2) see if there is a second wire from the alternator stud to the battery or the starter relay. If so, then the PO arranged a direct charging wire from the alternator. It needs fusible link.
If you chose to reinstall a wire from the starter relay to the main splice, it would provide a shorter path for battery power during start up. But it too would need a fusible link.
Xtreamist
Well-Known Member
The battery is in the trunk with the battery wire going to the starter first then to the starter relay. Never would have thought the battery would need a fuse. What amperage is normally used for that? The alternator is a two field, not sure what the amp output is though, probably 60. It is on its way out anyway and will need replaced, too.
Battery in trunk. OK. That heavy cable is also supplying the starter during start. I don't know that you can fuse it. There should be a kill switch or quick disconnect on it.
Reading back to your post # 23. See if there is a wire to the alternator output stud from the starter relay. That's where the fusible link should be. If there isn't one, size it the same as stock, or if the new wire is larger, one size up. That's plenty to carry the loads.
As far as the wire from the main splice to the ammeter goes. I think leaving it is pretty safe and could be useful in the future.
That stud is a good place to attach a parallel wire from the alternator that goes through a grommet instead of the connector.
Or you can use it to reattach a battery feed into the passenger compartment.
If you attached a battery feed to the other side of the ammeter, it will show when the battery is feeding. However it will not show when the battery is charging because the shortest path from alternator to battery is the direct wire.
Two field terminals can be easily made to work the same as pre '70 with single field terminal. Simply run a jumper to ground from one of them.
Field is shorthand for magnetic field created by sending electricty through the rotor windings. Pre '70 alternators complete that circuit with one brush connected to the chassis ground. The circuit on later alternators is completed by having the voltage regulator control the ground.
Xtreamist
Well-Known Member
Well my alternator does not have two black wire feeds coming off of it. When I replace the alternator it will be at least a 60amp and two fields. What is the correct way to wire this alternator? Dark blue goes to the resistor and the volt reg. Green from the alternator to the other side of the volt regulator. Black wire (10ga.) to a 14ga. fuse link the the starter relay? At least this is the way it is hooked up now. The other side of the resistor has a wire going to the coil and ignition.
Another issue is there are a bunch of wires connected to the starter relay. I know one terminal is for a neutral safety switch (or it is grounded to bypass that) one is for the ignition, one is for the starter solenoid, but what I don't get is what all connects to the large battery lug on the relay? Currently the large blue wire goes to the starter, there is a red wire with a factory appearing fuse link that goes to the bulkhead connector (traced this, it is the red to the ammeter) the black CB looking wire goes to toggle switch #1 in the drivers compartment (I have questions on all four toggle switches in there too! it looks like the CB wire is used as a power source for 3 of the 4 toggles) and there is a black wire, actually a solid copper house wire, that goes to toggle switch #2. On the solenoid terminal there is a green wire, which is a solid copper house wire too, that goes to toggle switch #2. Of course one wire form it goes to the starter solenoid. Toggle switch #1 goes to the starter relay and an aftermarket tach. Toggle switch #2 starts the car via the house wires, lol. Toggle switch #3 is fed/jumped from #1 and goes to the red wire on the Mallory 12V coil. Toggle switch #4 is fed/jumped from #3 and goes to an aftermarket ammeter and oil pressure gauge but neither work, it just for the bulbs.
Sorry, I sort of strayed from the MAD bypass question here.....
Here is the toggle switch panel
Another issue is there are a bunch of wires connected to the starter relay. I know one terminal is for a neutral safety switch (or it is grounded to bypass that) one is for the ignition, one is for the starter solenoid, but what I don't get is what all connects to the large battery lug on the relay? Currently the large blue wire goes to the starter, there is a red wire with a factory appearing fuse link that goes to the bulkhead connector (traced this, it is the red to the ammeter) the black CB looking wire goes to toggle switch #1 in the drivers compartment (I have questions on all four toggle switches in there too! it looks like the CB wire is used as a power source for 3 of the 4 toggles) and there is a black wire, actually a solid copper house wire, that goes to toggle switch #2. On the solenoid terminal there is a green wire, which is a solid copper house wire too, that goes to toggle switch #2. Of course one wire form it goes to the starter solenoid. Toggle switch #1 goes to the starter relay and an aftermarket tach. Toggle switch #2 starts the car via the house wires, lol. Toggle switch #3 is fed/jumped from #1 and goes to the red wire on the Mallory 12V coil. Toggle switch #4 is fed/jumped from #3 and goes to an aftermarket ammeter and oil pressure gauge but neither work, it just for the bulbs.
Sorry, I sort of strayed from the MAD bypass question here.....
Here is the toggle switch panel
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Xtreamist
Well-Known Member
I appreciate everyones help and patience with me. What use would leaving that in be? As a hot feed for something else? I wouldn't have any wires connected to the ammeter.
And its a safe, secure way to terminate that wire.
Not a problem with me. The original thread was from 2014 - I doubt your stepping on anyone's toes. If you want to start your own thread, or have a moderator help seperate, I'm sure one of them would help.
What electrical equipment will this car have?
That would be OK location for the link as well. Although maybe not the best with the other wiring mods done.
Which raises a couple questions. I'm OK with trying help unravel the existing system, but some place you mentioned returning the system closer to stock. Before we get too deep. Will this car continue to be a race car? What is/are your goals with respect to wiring?
At first glance, the stud is being used as a power distribution point.
Before you thought the ammeter was not connected. So does this red wire stop at the bulkhead connector? Or does it go on to connect to the ammeter? And if it does, does it share a stud with the wire from the main splice?
Uh?
In the photo you labeled this one as alternator feed,
and the dirty yellow as starter feed with fusible link.
If the photo is correct, then the original alternator feed to the main splice connects to nothing at the bulkhead?
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Xtreamist
Well-Known Member
Yea, I had the large blue wire labeled wrong in the photo. It comes from the starter not alternator. The dirty yellow wire does not have a fuse link. It does go to the ignition switch, slot L on the bulkhead connector. I was actually fixing the photo while you were replying to all the quotes.
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Xtreamist
Well-Known Member
Just the basics, lights, heater. I'm redoing it to be a street legal strip/bracket car. Have electric fans but they are not in yet and not sure if they are even going to be put in. Maybe I could go with a single field alternator?
I really do appreciate ypur help on this! Yea, race car that can be street driven. Not necessarily to OEM specs but it doesn't appear correct the way things are spliced/hacked together. Basically I'm cleaning the appearance up some and most importantly making good safe connections.
That's what it looks like to me too. Is there anything wrong with all those wires hooked to the lug? There are a lot coming off of it.
Yea, the ammeter is not connected to any wires under the dash. Looks like an attempt was made to do the bypass. I traced the red wire with the fuse link to slot Z (and it was melted pretty bad) on the bulkhead connector and it leads to the ammeter.
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Without the electic fans, stock alternator will be fine. If the car will be idling in traffic or used for putt putt parade stuff with any combo of lights, heater fan, and wipers on - that's when a little better output at idle speed is nice.
OK. Do you want to eliminate all or some of the toggle switches and use the ignition switch?
Depends on the wiring strategy. So far, it seems like the previous owner knew what he was doing. If you want to do it more neatly, you could have a little distribution box on the inner fender.
Got it. Its a dead end now.
Xtreamist
Well-Known Member
I would like to keep all the toggle switches. I'm not sure if the keyed ignition switch even works. I asked the POs wife (her deceased husbands car) if the key was needed to start the car and she wasn't sure.
That's a fine idea...
Xtreamist
Well-Known Member
The car did run, needed some minor work but it started and ran the way he had it. Has a Mallory dist. too
That's a big help.
OK. After dinner I'll try to draw out a schematic.
I've got a few different versions. Not sure which will be the best starting point in this case.
Maybe this one. It's worth looking at anyway so you can see the original layout.
Its also a good example of how a schematic can be made from the wiring diagrams.
Xtreamist
Well-Known Member
I have this one too and have studied it. What was throwing me on this one though is the feed from the batt going to both the starter and the starter relay and the single field alternator. I'm replacing what appeared to be bad connections and cleaning the engine bay up some.
If I understand the question is about the original system.
The Chrysler starter system has two stages.
When the ignition switch is in Start, power flows through wires S1, S2 and S4 causing the relay to close.
The Relay then connects Battery A1A to S5 which energizes the starter solenoid.
When the solenoid moves forward, the starter circuit A1 to ground, gets completed. A1 provides the battery power needed to turn the starter.
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The next car I buy from the 60s or 70s, I am going to buy all the wiring harnesses up front and change them all out. I think I wound up buying most of them anyway to get where I am at, but it would have saved me a whole bunch of time and aggravation chasing a whole herd of sparky gremlins. One of my friends did that and it only cost about $700 with a good sale for a body.
That still doesn't change the crappy charging route, but, you do have decent wires to start with.
Yeah, you correct about that, and probably a bunch of other stuff too like dim headlights, but they worked ok for a half a dozen years new, so it might get me by for quite awhile being a fair weather driver. I bought the under hood harness that was already wired for electronic ignition and the solid state regulator. That worked out really nice.
This is as much as I can figure so far.
The biggest question is how does the alternator output connect to the ignition and battery?
Switches
1. Tach. But maybe also something else?
2. Start. Apparently powers starter relay?? In which case, S2 yellow has to ground somewhere.
3. Run. Power to ignition coil and MSD 5900
4. Gage Illumination.
Xtreamist
Well-Known Member
I am open to any and all suggestions you have on correcting this so it is safe, operational, and reliable.
Let me study that layout for a bit more. It appears you forgot to include the ammeter bypass. You show the alternator still going to the welded splice and not the starter relay. Maybe it would be best and easier to simply add in the red ammeter wire back in and connect it to the black ammeter feed to it to complete the bypass? or, since there is an aftermarket ammeter and oil pressure gauge (from toggle#4) re-route the original ammeter wires to it? it is not that far from the original in the dash and I would be up sizing the feeds.
A minor thing too is toggle#2's green wire goes to the sol.terminal on the starter relay.
The aftermarket tachometer is fed from toggle#1. I would defiantly need to keep the tach, it has a rev limiter and shift light.
Thanks Mattax.
Steve
This is where I got lost. I didn't see any wire on the starter relay marked alternator in the updated photo, and you wrote there is only one lead connector at the alternator output stud. Help me out here.
OK. I think I understand. That makes more sense. And then is a neutral safety switch used, or is it grounded to the fender or engine?
Thinking about it this morning, I'm guessing the light blue wire on the coil negative goes to the tachometer?
How best to clean it up will be easier once we see how power is distributed. That's why I didn't draw in all the wires for the tach etc.
Those will be easy to deal with once we know how power is getting from the alt and battery to the distribution points.
quick update. we'll clean it up later
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