Alternator for LED lights?

[DS71Cuda]

Hello my fellow members. I am working on a 1971 Barracuda. I am installing LED headlights, taillights, side marker lights and a Dakota Instrument rally gauges. I will also be running A/C. I read somewhere on one of those after market vendors that in order to not have any electrical issues with these items I should install a more powerful alternator. Does anyone know of a vendor who makes these and do y'all have any experience using one? Thanks in advance for all who help! Don

 

[MoparCarGuy]

Consider a Powermaster 95A alternator and a wiring upgrade to your main power feed to the starter relay.
Powermaster Catalog go to page 102.

FYI - Prepare for a "ammeter bypass" discussion which brings with it a lot of controversy on whether a bypass is needed or how to safely accomplish it.
Reader beware!

 

[DS71Cuda]

I will also be running A/C. If that makes a difference? What is better internally or externally regulated? I see some have a higher amp range like 165, 215. Thoughts on those?

 

[EV2RTSE]

I'm not familiar with the power requirements of the Dakota Digital gauges but wouldn't LED bulbs draw less power than the original incandescents? Be very careful running too much juice through the wiring in these cars. I know the 70 ebody alternator was only like 37 amps without a/c, and 60 amps with a/c. If you're going to be powering an amplifier and stereo or something for better sound I could see needing more power but other than that probably not.

 

[Mopars & Missiles]

LED's use MUCH LESS power than regular incandescent bulbs (like 85% LESS). I'm sure the Digital Dakota cluster uses LED's as well. So IMHO, no need to do anything to the alternator or wiring.

 

[Mopars & Missiles]

FWI, this is right out of the installation manual for the Dakota Digital instrument cluster.

CONST. POWER
Connect the CONST. POWER terminal to a +12V power from the fuse panel that is “hot” all of the
time, or a fussed wire (5-20 amp) direct to battery power. This terminal should have power all of the time.
The constant +12V supply source should be a fused 5 - 20 amp circuit, the system draws less than 1 amp,
so sharing an existing constant power circuit will generally be fine. Use 18 AWG wire to ensure the system
receives a sufficient power feed. This terminal keeps the clock memory as well as returning the needles to
zero when the system is shut off.
AUXILLARY CONNECTOR FOR BIM-SERIES
EXPANSION MODULES
MAN 6503147
ACC. POWER
Connect the ACC. POWER terminal to accessory +12V power from the fuse panel or vehicle wiring
harness. This terminal should have power when the key is on or in the ‘accessory’ position. In addition to
turning on the instrument cluster, this is also where the voltmeter gauge senses the vehicle electrical
system voltage. The accessory +12V supply source should be a fused 5 - 20 amp circuit, the system
draws less than 1 amp, so sharing an existing accessory circuit will generally be fine. Use 18 AWG wire to
ensure the system receives a sufficient power feed

 

[MoparCarGuy]

The stock charging system barely handles the stock accessories. The upgrade is to ensure that you have 12VDC to those accessories.
Your old original wiring has likely degraded due to corrosion under the insulation. Stranded wire oxidizes over time and resistivity increases which leads to an undervoltage when measured at those accessories. That notorious pulsing of your headlights at idle is a symptom you can eliminate.

Address the overall system now and reap the benefits.

 

[EV2RTSE]

Definitely agree, and something like 90a should probably be ok if needed but 165 or 215A could potentially be a great way to set a car on fire. Just trying to say it's much safer to reduce demand rather than increase supply.

I picked up one of crackedback's headlight relay kits for my build, my brother used one on his 70 R/T and it made a noticeable difference with the stock alternator and lighting. This reminds me, I need to order one of his a/c relays as well. I haven't seen him on here lately but he's been around on some of the other forums.

Headlight relay kit-
Plug and Play headlight relay kits

A/C relay-
AC Compressor Relay Kit - Plug and Play

 

[DS71Cuda]

I apologize Y'all, I forgot to also mention I am installing the new wiring from headlight to taillight from American Autowire for 70-74 E-body.

 

[DS71Cuda]

Definitely agree, and something like 90a should probably be ok if needed but 165 or 215A could potentially be a great way to set a car on fire. Just trying to say it's much safer to reduce demand rather than increase supply.

I picked up one of crackedback's headlight relay kits for my build, my brother used one on his 70 R/T and it made a noticeable difference with the stock alternator and lighting. This reminds me, I need to order one of his a/c relays as well. I haven't seen him on here lately but he's been around on some of the other forums.

Headlight relay kit-
Plug and Play headlight relay kits

A/C relay-
AC Compressor Relay Kit - Plug and Play

I apologize Y'all, I forgot to also mention I am installing the new wiring from headlight to taillight from American Autowire for 70-74 E-body.

 

[DS71Cuda]

The stock charging system barely handles the stock accessories. The upgrade is to ensure that you have 12VDC to those accessories.
Your old original wiring has likely degraded due to corrosion under the insulation. Stranded wire oxidizes over time and resistivity increases which leads to an undervoltage when measured at those accessories. That notorious pulsing of your headlights at idle is a symptom you can eliminate.

Address the overall system now and reap the benefits.

I apologize Y'all, I forgot to also mention I am installing the new wiring from headlight to taillight from American Autowire for 70-74 E-body.

 

[Challenger RTA]

I apologize Y'all, I forgot to also mention I am installing the new wiring from headlight to taillight from American Autowire for 70-74 E-body.

Doesn't matter. Still not adequate. I know nothing of AAW. I doubt they used 8 GA or bigger for load and battery wire. As stated above Primary and secondary circuit removes overload from under rated wiring. Relay circuit in short. Mostly for headlights, AC, fan motor, any high amp stereo and rear defrost. Other than that the wiring would handle the rest.
Dakota Instrument rally gauges have an amp gauge or volt gauge?

 

[Challenger RTA]

undervoltage

Electrical components have a tolerance of +or - 10%. Electronic components are less and it can damage them.

 

[Challenger RTA]

"ammeter bypass"

I didn't say it! I briefly looked at the AAW and it looks like there is an amp ( Or charging bypass) meter bypass. And may be a headlight relay circuit. But that doesn't fix the heavy loads going through the bulkhead. I would have to look at it closer.

 

[MoparCarGuy]

Dakota Digital's E-Body Rallye Instrument Cluster (pricey at $1,855.00) uses a voltmeter with a range of 9-17VDC. Gauge is labeled BATT for the voltmeter unlike the original Rallye Instrument Cluster which was labeled ALT for the ammeter.
Source: Dakota Digital RTX for 1970- 74 Dodge Challenger and 1970- 74 Cuda with Rallye dash