Bypassing the Amp gauge - Question about the MAD Electrical method
Revision possibility 1. Lets not reinvent the wheel.
Generally return everything pretty close to stock routing and use ignition switch.
1. May need a new ignition switch and connector. Switches should be easy to buy if needed.
2. Manual cut-off switch in trunk for 0 to 4 gage wire. This assumes a basic open/closed switch for a single heavy wire routed as it is now.
3. Use the factory oil pressure and ammeter gages if they are working. They're easier to see. Arguably the Sun will be a little more accurate. Others may say if you want accurate pressure, go mechanical. I like gages. I have oil temperature and mechanical oil pressure in the accusump under the dash. I think oil temperature is a good addition for racing. A voltmeter is convenient - just keep in mind it only reveals voltage at the location it taps in at. Fuel pressure is another one some people like. I don't think its much use down low - I have a mechanical one that straps to the cowl outside the front window. Haven't used it for a long time, but when I doubts about delivery, it was helpful.
4. Keep the toggle switch for ignition. The only reason for this is the MSD Blaster 5900. Reading two different sets of instructions it seems the 5900 needs at least 12 Volts. They also say to use the ballast resistor for the coil if so equiped. Obviously the PO didn't do this. Its obviously OK to race this way. The question is whether the new coil will tolerate the heat generated from running at 12 volts for hours on end. If so, the Start and Run Ignition circuits can be tied together and the toggle eliminated.
A1 is certainly larger than 6 gage due the distance. You'll have to see how much larger.
A1A should 10 AWG or even 8 AWG because the location can get hot and its longer than the original routing.
Hot wires don't conduct as well. A wire with oil resistant, high temperature insulation would be best here.
Starter Relay. The owner may have bypassed this because it didn't work. May need a new one.
Fusible link. Same as stock, but connect one end to the stud with a ring terminal, the other with a connector to A1B.
A1B should be at least 12 gage. Its not carrying any more load that stock or going further distance.
But the connector at Z is damaged. Run A1B direct to the ammeter and use a ring terminal. Obviously use a grommet at the firewall.
Ammeter. If there's no sign of damage, I'd use it. Look for heat warping and gently check the studs to make sure they are not loose. If it is damaged, either use the Sun, or attach it on the alternator side. If its working, the ammeter will show whether the alternator is keeping up, or the battery is providing power (which is bad).
R6 Alternator output. If connection at P is OK, it still would be good to run a parallel 12 gage wire through the firewall to the ammeter alt terminal. This eliminates the firewall connection and the main splice when current is flowing to the battery for recharging. It provides a second route to the mainsplice for everything else.
Toggle 1- Tach. Power. Attach in fuse box. Tach will work when ever the ignition switch is in Run or Acc.
Toggle 2 - Start. Wont be needed if S2 is connected to a working starter switch and relay.
Toggle 3 - Blaster Power. May be needed - Could tap into any location that is hot in both Start and Run. This isn't great because it could accidently be left on. One easy location is the unused and unfused Hot terminal in the fuse box. Another would be the Alt. stud on the ammeter. A third location could be a splice into the power feed of the ignition switch.
Toggle 4 - Gage illumination. Tap into the instrument panel illumination at the fuse.
Oops. Forgot the Neutral Safety Switch. You know what to do there.
MSD 5900 Blaster. Shown here is assuming the coil is best off getting power through a ballast resistor.
If not, then toggle 3 can be eliminated entirely, and the ballast resistor can be replaced with a connector.
Revision possibility 1. Lets not reinvent the wheel.
Generally return everything pretty close to stock routing and use ignition switch.
1. May need a new ignition switch and connector. Switches should be easy to buy if needed.
2. Manual cut-off switch in trunk for 0 to 4 gage wire. This assumes a basic open/closed switch for a single heavy wire routed as it is now.
3. Use the factory oil pressure and ammeter gages if they are working. They're easier to see. Arguably the Sun will be a little more accurate. Others may say if you want accurate pressure, go mechanical. I like gages. I have oil temperature and mechanical oil pressure in the accusump under the dash. I think oil temperature is a good addition for racing. A voltmeter is convenient - just keep in mind it only reveals voltage at the location it taps in at. Fuel pressure is another one some people like. I don't think its much use down low - I have a mechanical one that straps to the cowl outside the front window. Haven't used it for a long time, but when I doubts about delivery, it was helpful.
4. Keep the toggle switch for ignition. The only reason for this is the MSD Blaster 5900. Reading two different sets of instructions it seems the 5900 needs at least 12 Volts. They also say to use the ballast resistor for the coil if so equiped. Obviously the PO didn't do this. Its obviously OK to race this way. The question is whether the new coil will tolerate the heat generated from running at 12 volts for hours on end. If so, the Start and Run Ignition circuits can be tied together and the toggle eliminated.
A1 is certainly larger than 6 gage due the distance. You'll have to see how much larger.
A1A should 10 AWG or even 8 AWG because the location can get hot and its longer than the original routing.
Hot wires don't conduct as well. A wire with oil resistant, high temperature insulation would be best here.
Starter Relay. The owner may have bypassed this because it didn't work. May need a new one.
Fusible link. Same as stock, but connect one end to the stud with a ring terminal, the other with a connector to A1B.
A1B should be at least 12 gage. Its not carrying any more load that stock or going further distance.
But the connector at Z is damaged. Run A1B direct to the ammeter and use a ring terminal. Obviously use a grommet at the firewall.
Ammeter. If there's no sign of damage, I'd use it. Look for heat warping and gently check the studs to make sure they are not loose. If it is damaged, either use the Sun, or attach it on the alternator side. If its working, the ammeter will show whether the alternator is keeping up, or the battery is providing power (which is bad).
R6 Alternator output. If connection at P is OK, it still would be good to run a parallel 12 gage wire through the firewall to the ammeter alt terminal. This eliminates the firewall connection and the main splice when current is flowing to the battery for recharging. It provides a second route to the mainsplice for everything else.
Toggle 1- Tach. Power. Attach in fuse box. Tach will work when ever the ignition switch is in Run or Acc.
Toggle 2 - Start. Wont be needed if S2 is connected to a working starter switch and relay.
Toggle 3 - Blaster Power. May be needed - Could tap into any location that is hot in both Start and Run. This isn't great because it could accidently be left on. One easy location is the unused and unfused Hot terminal in the fuse box. Another would be the Alt. stud on the ammeter. A third location could be a splice into the power feed of the ignition switch.
Toggle 4 - Gage illumination. Tap into the instrument panel illumination at the fuse.
Oops. Forgot the Neutral Safety Switch. You know what to do there.
MSD 5900 Blaster. Shown here is assuming the coil is best off getting power through a ballast resistor.
If not, then toggle 3 can be eliminated entirely, and the ballast resistor can be replaced with a connector.
