Alternator upgrade

[Erico624]

Hello i am upgrading my alternator to a 70 amp its serp belt system. Wires kinda have me confused.please help where does the wires go to?

 

[KD4UPL]

Depending on what you are upgrading from and too you may or may not use all the same wires. Your post is way to vauge to answer.

 

[Scott Danforth]

If you are installing a larger alternator, you will need to up-size the cable from the B terminal to the battery

Wire colors are standardized as to their function.

Check the sticky in the electrical forum for the wire color standard

 

[Erico624]

I

If you are installing a larger alternator, you will need to up-size the cable from the B terminal to the battery

Wire colors are standardized as to their function.

Check the sticky in the electrical forum for the wire color standard

thank you. Just need to figure out the red with blue or purply line from the 50 amp circuit breaker goes to.

 

[Erico624]

If you are installing a larger alternator, you will need to up-size the cable from the B terminal to the battery

Wire colors are standardized as to their function.

Check the sticky in the electrical forum for the wire color standard

Sorry the engine i have and boat is a project. Didn’t come with Alternator.

 

[alldodge]

Sorry the engine i have and boat is a project. Didn’t come with Alternator.

Which ALT are you installing?

 

[Erico624]

Which ALT are you installing?

 

[alldodge]

The pigtail has 2 wires coming from the ALT.
One wire goes to the Red/Purple which is the sense lead (50 amp breaker)
Other wire goes to purple which is excite (key switch turns ON)

I'm unable to find a wiring diagram for the exact ALT and it may not matter which lead goes to which but they do need to be separated

 

[Erico624]

The pigtail has 2 wires coming from the ALT.
One wire goes to the Red/Purple which is the sense lead (50 amp breaker)
Other wire goes to purple which is excite (key switch turns ON)

I'm unable to find a wiring diagram for the exact ALT and it may not matter which lead goes to which but they do need to be separated

Thank you! I will separate them.

 

[Erico624]

The pigtail has 2 wires coming from the ALT.
One wire goes to the Red/Purple which is the sense lead (50 amp breaker)
Other wire goes to purple which is excite (key switch turns ON)

I'm unable to find a wiring diagram for the exact ALT and it may not matter which lead goes to which but they do need to be separated

 

[Erico624]

The pigtail has 2 wires coming from the ALT.
One wire goes to the Red/Purple which is the sense lead (50 amp breaker)
Other wire goes to purple which is excite (key switch turns ON)

I'm unable to find a wiring diagram for the exact ALT and it may not matter which lead goes to which but they do need to be separated

Hello this is what i got from DB electric for what pin does what.

 

[Scott Danforth]

one wire is the ignition reference, one is the idiot lamp.

S = Sense wire. this is purple and comes from your key switch
L = Lamp. this is a ground feed to your lamp (the other side of the lamp goes to the ignition switch.)

 

[Erico624]

one wire is the ignition reference, one is the idiot lamp.

S = Sense wire. this is purple and comes from your key switch
L = Lamp. this is a ground feed to your lamp (the other side of the lamp goes to the ignition switch.)

Purple from key this is the purple from the engine connector correct? Sorry still have motor out of the boat.

 

[alldodge]

Purple from key this is the purple from the engine connector correct? Sorry still have motor out of the boat.

Yes, purple is purple anywhere from the helm to throughout the motor "unless" someone has bugged things up

Color codes for Merc

 

[Erico624]

Yes, purple is purple anywhere from the helm to throughout the motor "unless" someone has bugged things up

Color codes for Merc
View attachment 378823

Thank you! Now i know where the connector goes. Little orange wire from starter to plus and ground also from harness to ground on alternator. Should use battery positive and negative cables from the alternator to the battery also?

 

[alldodge]

Thank you! Now i know where the connector goes. Little orange wire from starter to plus and ground also from harness to ground on alternator. Should use battery positive and negative cables from the alternator to the battery also?

ALT orange wire should go to the starter post thru a 90amp fuse. This way if the ALT shorts out it will not melt the wiring. Note the starter pic below does not show the orange connected to the fuse but it should be

 

[Erico624]

ALT orange wire should go to the starter post thru a 90amp fuse. This way if the ALT shorts out it will not melt the wiring. Note the starter pic below does not show the orange connected to the fuse but it should be

View attachment 378828View attachment 378829

Ok thank you!

 

[Erico624]

ALT orange wire should go to the starter post thru a 90amp fuse. This way if the ALT shorts out it will not melt the wiring. Note the starter pic below does not show the orange connected to the fuse but it should be

View attachment 378828View attachment 378829

Did i get it right by saying i needed to add the battery cables to the ground and + on the Alternator? Want to make sure.

 

[alldodge]

Did i get it right by saying i needed to add the battery cables to the ground and + on the Alternator? Want to make sure.

Bat cables, + or - do not go direct to ALT
Orange goes to 90 amp fuse on starter post. Bat + side goes to starter post
Black goes to pin 1 on the 10 pin Connector or other location or the block

 

[Erico624]

Bat cables, + or - do not go direct to ALT
Orange goes to 90 amp fuse on starter post. Bat + side goes to starter post
Black goes to pin 1 on the 10 pin Connector or other location or the block

Thank you alldodge! You are the best!