Alternator Wiring Question • The Dodge Challenger Message Board

by **Jon** » 12 Mar 2009 14:21

I am looking at a 100 amp alternator for my 70 and wondering if there are any wire size concerns with the increased amps?

The wire from the alternator to the bulkhead is rerouted to the starter relay (not through the amp meter) using #10 wire.

Jon

by **drewcrane** » 12 Mar 2009 15:21

i have heard about by passing the amp meter and going directly to the starter relay, , i have mine running through amp meter, how ever my batterery is in the trunk and if my car vapor locks i have a hard start problem ,my battery is not getting enough charge from the alternator, so my plan is to use some 10# wire and by pass the amp meter ,not to sure about this but i might try , do you have your hooked up yet let me know how it works ,

and Dave R. what do you think about this mod?

by **Eddie** » 12 Mar 2009 15:29

Just out of curiosity why do you need a 100 amp alternator?

by **Jon** » 12 Mar 2009 15:35

Drew, I have had the bypass for a couple of years now the only draw back is the amp gauge reads below normal levels however it still moves with the draw/charging.

Eddie, I found a good price for a reman chromed unit and it happens to be 100 amp.

by **Eddie** » 12 Mar 2009 15:46

Jon wrote:Drew, I have had the bypass for a couple of years now the only draw back is the amp gauge reads below normal levels however it still moves with the draw/charging.

Eddie, I found a good price for a reman chromed unit and it happens to be 100 amp.

I see! Cool. :thumbsup:

by **dave-r** » 12 Mar 2009 16:58

The amount of current supplied by the alternator depends on the amount demanded by the system.

In other words, just because you fitted an alternator that can put out 100amps, it does not mean that your system will now be carrying 100 amps. All it means is that you can draw that amount before the alternator starts to struggle.

I have heard that "bigger" alternators do not work so well at idle. But this is only what I heard and have nothing to back that up.

So the short answer is. It makes no difference to your wiring if you fit this alternator.

by **Eddie** » 12 Mar 2009 17:13

Here's a good diagram of upgrading the ammeter with a voltmeter, and bypassing this source when increasing the current as I think you are contemplating Drew. http://www.madelectrical.com/electrical ... uges.shtml I think Dave-R turned me on to this site! :lol:

by **drewcrane** » 12 Mar 2009 17:55

I need a 100 amp alt. so i can run sirens and lights big thumpin stero,bells whistles, i dunno it .....no the reason i did it is there is a company that makes them for march pulleys system and after dissemblying my alt. to put the special pulley in it i screwed it up so i got a hold of Tuff Stuff and the had one in stock with the pulley on it so now i have a 100 amp alt. and no where to dance with it , i might do this electrical wire swap sooner rather than later,but that is why :s009:

by **drewcrane** » 12 Mar 2009 17:56

Jon wrote:Drew, I have had the bypass for a couple of years now the only draw back is the amp gauge reads below normal levels however it still moves with the draw/charging.

Eddie, I found a good price for a reman chromed unit and it happens to be 100 amp.

thanks jon now i atleast your car didnt burn to the ground with this mod :thumbsup:

by **Jimiboy** » 12 Mar 2009 19:15

drewcrane wrote:I need a 100 amp alt. so i can run sirens and lights big thumpin stero,bells whistles, i dunno it .....no the reason i did it is there is a company that makes them for march pulleys system and after dissemblying my alt. to put the special pulley in it i screwed it up so i got a hold of Tuff Stuff and the had one in stock with the pulley on it so now i have a 100 amp alt. and no where to dance with it , i might do this electrical wire swap sooner rather than later,but that is why

Why a "big thumpin stereo" Drew? Are'nt the sweet sound from your engine like music enough in your ears? :wink:

by **Jon** » 12 Mar 2009 21:48

Learned the bypass setup from this message board. Now I feel comfortable the amp gauge won't case a fire if it malfunctions. Only thing is question is the red supply wire to the gauge which is still intact but it's lower draw now.

Dave, i thought maybe the 100 amp alt would help the idle current also and that would be a bonus. Not worth spending $100 to find out though.

I will say getting rid of the amp gauge loop did help with the slow blinkers though. Must have been a bad (alt) connection at the bulkhead or something.

As for thumpin stereos, I agree with Jimi, the engine is all I want to hear when driving. :rage:

I do remember cranking the old Motorola to the max hanging out at the look out spot though. :s023:

by **dave-r** » 12 Mar 2009 22:14

Jon wrote: I will say getting rid of the amp gauge loop did help with the slow blinkers though. Must have been a bad (alt) connection at the bulkhead or something.

If you haven't fixed that bad connection at the bulkhead you still need too. It will improve things futher and if left it could cause more damage to the bulkhead connector.

You will be able to tell which connection it is by looking at it. It will be the one with the burnt spade and burnt plastic around it. :wink:

by **drewcrane** » 12 Mar 2009 22:16

im kidding i have something that says sony but sounds like a transistor radio ,but its 4 speakers and tunes because i do drive mine for a few hours at a time and i gotta tell ya with my wife in the car she is kinda soft spoken and i am hard of hearing i have to let off the gas just so i can hear her :disbelief:

so a big thumping stereo wont have a chance against 3 inch pipes, im sure you can hear them in the vid , my car is LOUD at wot :rage:

by **Jon** » 13 Mar 2009 1:20

When kickin back, the drill was to start your engine once in a while to recharge the stereo. Heck, that's all that really mattered. Getting home was a simple bump start. :lol:

by **drewcrane** » 13 Mar 2009 1:54

It will be the one with the burnt spade and burnt plastic, i have had to fix that already, thanks for reminding me i need to do that to the gran cpe.

by **Jimiboy** » 13 Mar 2009 7:04

drewcrane wrote::s001: im kidding i have something that says sony but sounds like a transistor radio ,but its 4 speakers and tunes because i do drive mine for a few hours at a time and i gotta tell ya with my wife in the car she is kinda soft spoken and i am hard of hearing i have to let off the gas just so i can hear her so a big thumping stereo wont have a chance against 3 inch pipes, im sure you can hear them in the vid , my car is LOUD at wot

Just kiddi'n you Drew.. :mrgreen:

Sure, i also have some sort of mp3 with small 4" speakers at the front kickpanels... Sometimes it is nice to blend up the loud pipes with some good old AC/DC...

I just met a girl that is quite soft speaking... **I wonder how i ever is gonna hear her voice in the Beast! :mrgreen:

(maybe we should tip Ed about this) :s004:

3" with no muffles, haha!

**Still winter, not taken the beast on the roads yet....

Btw, i run without the amp gauge to my Bosch alt. and a relay/carbon extra with me in the car... This works for me...

by **Jon** » 13 Mar 2009 13:53

Don't worry Jimi, women start talking louder and louder (and more often)the longer you know them. Pretty soon your setup will be a good thing. :lol:

I carry all the replacement electrical in the trunk also. Only lacking a spare alternator.

by **drewcrane** » 13 Mar 2009 17:54

soft speaking,hope fully not much needs to be said, hay thanks for the info jimi i can use a relay too! good idea :thumbsup:

by **Jimiboy** » 13 Mar 2009 17:56

Jon wrote:Don't worry Jimi, women start talking louder and louder (and more often)the longer you know them. Pretty soon your setup will be a good thing. .

I believe you Jon... :biggrin:

Jon wrote:I carry all the replacement electrical in the trunk also. Only lacking a spare alternator.

I did actually drove around with an old alternator in my daily driver, don't ask me why....

And it was a good thing that i had not "thrown it away"... because i actually did help a friend that was in desperate need of an relay/carbon to his car, in the middle of nowhere at the late night! (His car was out of power because of an worn relay in the alt...) :mrgreen:

It sure was his lucky day to have me close of just an coincidence ! :p:

by **Jon** » 18 Mar 2009 1:34

drewcrane wrote:i have heard about by passing the amp meter and going directly to the starter relay, , i have mine running through amp meter, how ever my batterery is in the trunk and if my car vapor locks i have a hard start problem ,my battery is not getting enough charge from the alternator, so my plan is to use some 10# wire and by pass the amp meter ,not to sure about this but i might try , do you have your hooked up yet let me know how it works ,

and Dave R. what do you think about this mod?

What circuits are running from the remote battery to the engine compartment? Is there a small wire to the relay along the heavy starter wire? If so, you could just connect the alternator feed at the relay. (Clip and reroute the black wire at the bulkhead but leave a little just incase you want to change it back.)

by **dave-r** » 18 Mar 2009 10:07

Trunk mounted battery's should be connected directly to the starter motor. You then run a heavy wire from that post on the starter to the relay.
You can connect the alternator directly to either the starter or the relay. But make sure you put a fuse in that cable.