another amp meter bypass question?

[northeastmopar]

I upgraded my dash and installed a volt meter. (see pictures). I took the black and red wires at the old amp meter and soldered them together right at where they were located for the amp meter. Installed shrink tube and then taped over for a good connection. I installed the volt meter by taking the feed from the blue ignition wire and then grounded the other side along with the other gauges I installed. I have a brand new M&H engine harness with the correct fusible link on the red wire which goes to the starter relay. Because the engine harness is brand new I also have the heavy black wire, which when plugged into the main dash bulkhead it aligns itself with the black side which use to go to the other side of the amp meter. I understand I need to run a black 10 wire from the alternator to the starter relay and install a 14 GA fusible link on this wire at the relay. Somewhere I am losing what happens to the black wire already installed in the new harness when I plug it in to the bulkhead connector black wire?? Do I need to do something with the black connection at the bulkhead, or do I just leave them plugged in as they would normally be? I don't see any fusible links along that black wire in the new engine harness. So is the link I am installing at the starter relay an additional link protection?

 

[diymirage]

that is one fast office chair you got there buddy

 

[Dubob]

If your doing the mad wiring, the black is used as another conductor for power to the inside of the car thru the bulk head connector, this increases the actual gauge of the wire carrying the load. Here's the diagram from the mad website if it helps. The black and red share a fuse link at the power source. This protects the complete run of both wires. Hope this helps.

 

[northeastmopar]

that is one fast office chair you got there buddy

you noticed. I am hoping that will correct itself when it is powered up and I think it needs to be calibrated once online. so its not a fast chair. more of a stuck needle. brand new out of the box that way......

 

[northeastmopar]

If your doing the mad wiring, the black is used as another conductor for power to the inside of the car thru the bulk head connector, this increases the actual gauge of the wire carrying the load. Here's the diagram from the mad website if it helps. The black and red share a fuse link at the power source. This protects the complete run of both wires. Hope this helps.

I was wondering if just leaving the wires plugged together at the bulkhead now would do the same thing or cause a problem?? I just wanted to run a new black from the alternator to the starter relay and then just leave the bulkhead connections as is? Power thru the black from the alternator to the starter relay, thru the red fusible link and continue thru the red/black splice where the ampmeter was. But leave the black from the ampmeter splice in the bulkhead and pluf the engine harness black into it? What would the end result be??

 

[Dubob]

If you leave the black wire that normally would connect to the alternator hooked to the alternator and it's also carrying power as it normally would to the ammeter, there will be no load protection on it. If you unhook it and just use the red, the black wire normally going to the alternator would need to be insulated so it doesn't short. The idea behind using both the black and red going thru the connector like the mad diagram is it reduces the amount of current that the pins and wires carry. The one red wire would be carrying all the load of whatever the car needs if you don't use the black at all. Personally I don't think that's a good idea as the pins in the bulkhead connector are part of the issue your trying to avoid. They get hot because they are too small to begin with and cause the connector to melt. A lot of people will remove the red wire and run a heavier gauge wire to the inside of the car and splice into the harness under the dash, this eliminates the lite wire and pins all together, the black wire can be totally taken out of the system doing this also. But you have to drill thru the bulkhead connector or fire wall to run the heavier wire. You'd still need the wire from the alt to the starter relay as you have planned.

 

[northeastmopar]

If you leave the black wire that normally would connect to the alternator hooked to the alternator and it's also carrying power as it normally would to the ammeter, there will be no load protection on it. If you unhook it and just use the red, the black wire normally going to the alternator would need to be insulated so it doesn't short. The idea behind using both the black and red going thru the connector like the mad diagram is it reduces the amount of current that the pins and wires carry. The one red wire would be carrying all the load of whatever the car needs if you don't use the black at all. Personally I don't think that's a good idea as the pins in the bulkhead connector are part of the issue your trying to avoid. They get hot because they are too small to begin with and cause the connector to melt. A lot of people will remove the red wire and run a heavier gauge wire to the inside of the car and splice into the harness under the dash, this eliminates the lite wire and pins all together, the black wire can be totally taken out of the system doing this also. But you have to drill thru the bulkhead connector or fire wall to run the heavier wire. You'd still need the wire from the alt to the starter relay as you have planned.

So, if I do the Mad electric move, where to I actually tie the red and black together. In the engine bay before the bulkhead and then just let the wires pass through the bulkhead with on spade plugs involved. I understand I can leave a small loop under the dash to pull the wire through if I need to work on the firewall side of that connector plug?

 

[70dustah]

Tie the red and black together at the fuse able link, since they both now provide power to the interior. I am confused on what you are saying after that? Please reword

 

[diymirage]

you noticed. I am hoping that will correct itself when it is powered up and I think it needs to be calibrated once online. so its not a fast chair. more of a stuck needle. brand new out of the box that way......

did you mention it to the manufacturer yet ?
I do like the way those gauges look its on my list (but a ways down)

 

[Pete in NH]

Hi,

I think that hole Mad Electric conversion is overly complicated. I would tape back and insulate the original black alternator output wire so it doesn't short to anything.

Then I would run a new #8 black wire from the alternator output stud to the 5/16
' battery stud on the starter relay. This wire should have a fuse or fusible link in it sized according to the alternator you are using. Then run a new #8 red wire from the battery stud on the starter relay through the firewall and connect it to the black wire that used to go to the ammeter. This wire should be fused with a blue #16 gauge fusible link or a 50 amp Maxi--Fuse blade type fuse in a holder. This is a much simpler, reliable system than the Mad Electric set up.

 

[Logan]

I'll be doing this in the next few days and plan to pass new wires through the bulkhead fitting without any connections.
One thing I plan to do differently than suggested here, tough, is connect the voltmeter to ground on one end and the other terminal to a light ga wire soldered into the under dash splice MAD shows. This way, the guage will read the voltage drop created by the ignition, headlights, etc.. Essentially everything that uses juice except the starter which shouldn't be connected to the volt meter anyway.
Then, if the voltmeter shows discharge, it will say that the alternator isn't keeping up to what the system requires and the problem needs to be addressed.