Bypassing (removing) the ammeter on a 1973 Charger (need advice)

[nge]

Hi all,
I was just looking at at the old 1973 wiring diagram thread and I wanted to know the best way to bypass the ammeter. 
I'm switching to a voltmeter.
I thought about just connecting the two wires to the ammeter together but then I thought it would be best NOT to have an unused HOT wire under the dash for no reason. 
Using the 1973 wiring diagram, can I just connect the starter relay wire (to the ammeter) directly to the alternator (from the ammeter)....these are the two darkest lines on schematic.
any advice or lessons learned would be most appreciated!!
thanks
Vic

[nge]

BTW
I did read the exellent "MAD" article posted by Nacho-RT74, but I am confused as to why the fusible links need to be added ( as opposed to just bypassing the ammeter with a good solid splice).
v/r
Victor

[Nacho-RT74]

fuse link is needed for safety in case of a short...

I posted the MAD article just to compare they are wrong LOL.

Honestly, no need to bypass the ammeter, just bypass the bulkhead connectors

[Pete in NH]

Hi,

I agree with Nacho, if you are using a stock alternator no need to bypass the ammeter, just the bulkhead connector. If, however, you are using a much bigger than stock alternator going to a voltmeter is the thing to do.

If you are using a stock alternator the "fleet bypass" modification is the way to go. This bypasses the bulkhead connector.Run a new piece of #8 wire from the starter relay stud directly to the ammeter post through a grommet-ed hole in the firewall. You should have a fusible link or Maxi-Fuse in this line. Then run another piece of 38 wire from the other side of the ammeter through  the grommet-ed hole to the alternator output stud. On this side of the ammeter there is a black wire that goes to a big splice joint that powers the whole car, you need to find that connection and keep it. however, you can disconnect the wires that went to the bulkhead connector pins. Chrysler used this wiring when using 60 amp alternators from the factory.

If you are going to a bigger alternator, run a #6 wire from the alternator output to the starter relay battery stud through a fusible link or Maxi-Fuse rated close to the alternator output. then run another #8 wire from the starter relay battery stud through a blue fusible link or 50 amp Maxi-fuse through the firewall to the splice joint that the black ammeter wire went to. Then completely remove the original ammeter connections.

Anyway, that's how I would handle it.

[nge]

thanks!
yes I am going to a larger alternator.  While I am not anti-ammeter per se, Ive installed 2 Ron Francis Kits and his literature says someting like an voltemeter warns you of impending trouble before the fact while an ammeter tells you of touble after the fact. I have a 1966 truck, and a 1969 and 1973 car....so I was swayed by that.
Although....this site has made it super clear to me that most  ammeter problems stem from the bulkhead connectors

[Pete in NH]

An ammeter tells gives you slightly different information than a voltmeter. An ammeter shows you clearly whether current is flowing into or out of the battery and shows a relative amount. A voltmeter only implies current flow. If the system voltage is high enough current should be flowing into the battery and charging it or if the system voltage is low I would think current is likely flowing out of the battery. But, it never implies a relative amount.

I just personally perfer the information the ammeter gives as it clearly tells me about what the charging system is doing.

[Nacho-RT74]

no need for bypass the ammeter with a larger alt either... just, once again, bulkhead bypass

[nge]

Understand, the kit only has a voltmeter and I just wanted to be safe

[fy469rtse]

did the bypass , found down in in australia, made by Speco gauges , amp gauge, used the face from my gauge, fit easy, result reads the same as factory, without the load as per factory going through it, $ 18.00 + GST A steal, Ok , one more thing corrected repaired , off my list

[charger Downunder]

If using a higher amp alt run a bridge across the back of the amp gauge to take some current and the gauge will still move, you may have to try a few different wire sizes to get one that still leaves movement in the gauge. Plus bypass the bulkhead connector.

[Nacho-RT74]

that would be something like get a shunt, not exactly, but similar.

the big "problem" with ammeters wasn't really ONLY the ammeter itself, like the bad conections on studs

[texas charger 73]

So I can still hook up ammeter normal with a stock alternator as long as I just run a solid wire and fusible link through the bulkhead and do away with the cheap firewall/bulkhead connector? What size fusable link?,just one or two fusible links? Mad chart shows a 14g and a 16 g fusible link

[Pete in NH]

With a stock alternator I would keep the ammeter an just do what the factory called the fleet bypass modification. This gets the bulk head connector out of the way. Run a new #8 black wire from the alternator output stud, 1/4" ring terminal, through the firewall directly to the ammeter terminal with the black wire on it. Leave the factory black wire on the ammeter. Follow the existing alternator output wire back to the bulk head connector and cut it off at the connector.

Next remove the red wire from the ammeter and run a new #8 gauge red wire from the ammeter through the firewall to the 5/16" battery stud on the starter relay. Use a 50 amp Maxi-Fuse in a holder between the new red wire and the battery stud.

I think the Mad Electric mod is more complicated than it needs to be and I don't like the idea of drilling holes through the bulk head connector in case anyone wants to put things back like it left the factory.

[texas charger 73]

Ok I have already removed both wires from the bulkhead, what about the wires on the firewall side plug? Will i need to disconnect hot wire on engine side plug so there isnt a hot wire sitting there plugged into an open hole in the bulkhead?I'm gonna leave black wire from factory harness on ammeter with new black wire,but remove red wire.  Now i didn't get a maxi fuse, but I got an inline 14g and 16g fusible link. Will either of them work?, the reason I want to run a voltmeter separate is because it shows actual voltage and I got it on clearance at store for $8.  Was an amazing deal. 

[texas charger 73]

Looks like someone already tried to do a bypass,but no fusible link and still went through bulkhead.  Smh.  Time to fix if I can find a dang 50 amp fusible link

[Pete in NH]

Hi,

The fusible link on a 73 should be right off the 5/16" battery stud on the starter relay. There is a 5/16" ring terminal on one en and a single wire plug in connector on the other. This single wire connector goes to a wire that feeds into the bulk head connector and then to the ammeter. If you remove the original red wire an fusible link you will have disconnected the original power source.

An in line 14 gauge fusible link will be too big for a stock alternator, use the 16 gauge one. Connect one end of it to the starter relay battery stud an the other to the end of your new #8 gauge red wire. The new red wire then runs through the firewall to the ammeter terminal that ha the factory red wire on it. You will remove the factory red wire.

[texas charger 73]

This is the fusible link I bought and will install. Only one I could find that would hold a 50a fusible link.  The 16 and 14g ones I found only help like a 30a max small blade fuse

http://mobile.walmart.com/ip/Scosche-In-Line-Fuse-Block-With-40-and-80-Amp-Maxi-Fuse-PMFHIK/2606832

[texas charger 73]

This is what I originally bought but figure too small to run with 8g wire

http://m.oreillyauto.com/mt/www.oreillyauto.com/site/c/detail/CTI0/85627/N0220.oap?ck=Search_N0220_-1_643&pt=N0220&ppt=C0172

[texas charger 73]

So which one should I use before I install? Currently there is no fusible link on the car?,there makeshift fix had some cheap radio power wire with no fuse

[Pete in NH]

The O'Rielly link didn't work for me and I'm not sure what that Wallmart part really is.

I use NAPA part number NW784482 for the fuse holder and a 50 amp Maxi-Fuse also available from NAPA. The NAPA holder is a good quality part with heavy leads.

[texas charger 73]

walmart one is same concept,but instead of having wires come out each end you feed your 8g wire into it and crimp down

[VegasCharger]

The O'Rielly link didn't work for me and I'm not sure what that Wallmart part really is.

I use NAPA part number NW784482 for the fuse holder and a 50 amp Maxi-Fuse also available from NAPA. The NAPA holder is a good quality part with heavy leads.

NAPA Fuse Holder part #NW784482
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Fuse-Holder-Heavy-Duty-In-Line-Maxi-Fuse-Holder-w-Cover/_/R-NW_784482_0362425454

NAPA 50 amp Maxi-Fuse part #BK7822160
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Fuse-MAXI-Fuse-50-Amp/_/R-BK_7822160_0006409350

[polywideblock]

there on ebay to   http://www.ebay.com/itm/8-GAUGE-INLINE-MAXI-FUSE-HOLDER-WITH-60-AMP-FUSE-2-PIECES-TOTAL-NEW-/380936942629?pt=LH_DefaultDomain_0&hash=item58b19c7425