MAD ELECTRICAL?

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coalman

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Have any of you done this Amp Meter by pass? If so, looking at their picture of the 16 gage fusible Link coming off the starter relay, are both the Red and Black wires attached to the link, or are they spliced together further down??? Thanks a bunch
 
Have any of you done this Amp Meter by pass? If so, looking at their picture of the 16 gage fusible Link coming off the starter relay, are both the Red and Black wires attached to the link, or are they spliced together further down??? Thanks a bunch

The way they get re-wired the red and black form a parallel path. This does two things..........the new wiring sends charge current direct to battery, so charging current does not have to go through the bulkhead ammeter. This relieves strain on that wiring. Second, the parallel path means that the red and black, working in parallel, work as one big wire to feed current for the rest of the car.......headlights, heater, etc

Some guys don't like the way MAD does that and advocate simply jumpering from the alternator direct to the battery. That is OK, too, but it removes the fuse link protection........which is damn poor to start with

If you do that, I'd add a breaker/ fuse link to the new part of the circuit
 
The way they get re-wired the red and black form a parallel path. This does two things..........the new wiring sends charge current direct to battery, so charging current does not have to go through the bulkhead ammeter. This relieves strain on that wiring. Second, the parallel path means that the red and black, working in parallel, work as one big wire to feed current for the rest of the car.......headlights, heater, etc

Some guys don't like the way MAD does that and advocate simply jumpering from the alternator direct to the battery. That is OK, too, but it removes the fuse link protection........which is damn poor to start with

If you do that, I'd add a breaker/ fuse link to the new part of the circuit

I tried to call them, I think they leave the phone off the hook for guys like me. So both the red and black wires are spliced into the fusible link, or after further down the wire run? I am also thinking of running a 10 gage wire from the Alternator to the relay with a 14 gauge fusible link like the diagram shows as the 66 has a 12 gauge. Thanks for all your input!!!
 
I did the upgrade as MAD recommends. I also installed relays for my headlamps and for my dual electric fans. BTW, having a parallel feed through the bulkhead halves the current through the small bulkhead connectors which is the weak point.
 
I did the upgrade as MAD recommends. I also installed relays for my headlamps and for my dual electric fans. BTW, having a parallel feed through the bulkhead halves the current through the small bulkhead connectors which is the weak point.

I also did the headlight relay upgrade. Thanks
 
I did the upgrade as MAD recommends. I also installed relays for my headlamps and for my dual electric fans. BTW, having a parallel feed through the bulkhead halves the current through the small bulkhead connectors which is the weak point.

If I remember correctly, the madd electrical bypass shows doing away with the bulkhead connectors for the two wires we’re talking about. And drilling out the plastic and running continues wire through and back out, thus eliminating the connectors altogether. At least that’s how I did mine
 
If I remember correctly, the madd electrical bypass shows doing away with the bulkhead connectors for the two wires we’re talking about. And drilling out the plastic and running continues wire through and back out, thus eliminating the connectors altogether. At least that’s how I did mine

I agree, did you splice the black and red at the fusible link? Thanks for your reply
 
I agree, did you splice the black and red at the fusible link? Thanks for your reply
I did on mine, exactly as it's shown on the schematic
AMP-GA27.jpg


20170629_173908.jpg
 
Man you are up early, what model car did you do this to? Thanks
 
If I remember correctly, the madd electrical bypass shows doing away with the bulkhead connectors for the two wires we’re talking about. And drilling out the plastic and running continues wire through and back out, thus eliminating the connectors altogether. At least that’s how I did mine

I choose to keep the bulkhead connectors based on the current draw through the connectors was minimized even more by using headlamp relays.
 
The advantage of this is potentially better connections for the power when starting or running on the battery.
amp-ga27-jpg.jpg


But the disadvantage of this arrangement is power flows a longer distance and through two fusible links, which are by definition smaller wires.
MADB-running.jpg


Better to run the vehicle from a direct feed from the alternator as illustrated below.
MADB-revised-direct.jpg

Fusible links still protect equipment downstream from the battery.
When the engine is running, the alternator will recharge the battery through the wire marked Charging.
Everything else that's attached to the main junction gets power direct with just one splice.

During start, power will flow from the battery to the main junction through the path of least resistance - or some proportion of each if the resistances are similar.
 
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A variation on this is to run parallel wires through the bulkhead and instead of splicing, use ring terminals on the end and the ammeter stud(s) for the junction.
If not keeping the ammeter then this would require an stud insulated from the chassis.
If keeping the ammeter, it allows the option of bypassing it (everything attached to one stud) or keeping it in the charge circuit (wire from alternator to one stud, wire from battery to the other).
Some on the mopar forums call the parallel wires to the ammeter the "NachoRT" bulkhead bypass since he first posted this.

parallel-redrawn.JPG
 
West coast time, I just got home from work. This was a 69 GTX with factory alternator. I also added relays for the lights and fuel pump.

Thanks... I also have the head light and electric fuel pump relays....
 
I'm not a fan of the MAD method. I prefer to run a protected wire from the alt to starter relay, leave all OEM wires in place and bypass the ammeter. If the bulkhead is in good shape, go with it.

Plenty of ways to improve on the crummy charging route of our old mopars.

Pick your parts, pay your money.
 
I'm not a fan of the MAD method. I prefer to run a protected wire from the alt to starter relay, leave all OEM wires in place and bypass the ammeter. If the bulkhead is in good shape, go with it.

Plenty of ways to improve on the crummy charging route of our old mopars.

Pick your parts, pay your money.

Are you saying to run an extra wire from the alternator to the starter relay? My factory 12 gauge black wire runs from the alternator, to the bulkhead connector, and I have already bypassed the ammeter. Thanks for advice
 
I opened up the bulkhead connector today, a lot of corrosion in the 12 gauge alternator wire. the male pin was easy to clean up, not so much luck on the female side. I am going to clean it up the best I can see what happens. Thanks for everyone's input
 
Yes run an 8 gauge wire from charge stud to starter relay with a fusible link or fuse holder in it.

I build them.
 
The original wires Red and Black are both 12 gauge to the Amp gauge. I am looking at both ways of doing it. The first way is I am just going up to a 10 gauge wire from the Alternator to the starter relay as MAD shows. The other would be a 10 gauge with an inline fuse as you show. What do you think, and what AMP fuse? Thanks a lot...
 
upload_2018-9-2_8-36-13.jpeg


Here is one of the easiest to read current vs wire size charts that I have seen. Keep in mind that the circuit length includes the return (ground) side if it has a length of wire before it is tied to chassis ground.
 
As a general rule, wiring should be sized for twice the maximum current flow and fused at 1.5 times the max current flow. The length of the wire affects the wire size as shown in the chart also. Running over 80% of the rated fuse capacity will result in unpredictable fuse performance. It may work or you may blow fuses randomly.
 
Also, keep in mind that if you are running fusible links in parallel, you are doubling the maximum current you are allowing in the circuit. Fuses in parallel add. I’m not saying this is bad, maybe it is what you want. You should just be aware that you are doing it and make sure that the whole circuit can handle it.
 
If I run it as MAD shows the Red and Black from Ammeter are on one fusible link and the Black from alternator is on the other one. So is adding the other wire with a fuse not good? Thanks for your input...
 
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