Alternator electrical question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

R@nger · 06-17-2005, 11:36 PM

Ok well at the moment I have my fan shroud and fan off and I'm painting the fan shroud..can't stand the yellow, half painted mess that it has been since I got the truck

. Anyways with all the extra room I changed my alternator belt. This got me looking at the HORRIBLE wiring going on in my engine compartment. My question is, where are the wires from the alternator supposed to go? I looked at the wiring diagram posted in the FAQ section but its to complicated because my wiring is so messed up I can't even tell whats what. Right now they have the power from the alternator going to a 4 way pile up where it there continues through one wire across the radiator and into the fusebox maybe???...and then they have a wire connected directly to the positive battery post going across the radiator and again possibly into the fusebox???...its a horrible mess.

Just a little explaination of what wire goes where in the engine compartment would be a huge help...thanks

.

Longhorn Man · 06-18-2005, 07:20 AM

pics?

R@nger · 06-18-2005, 02:19 PM

Yeah I'll post some today...it was to dark lastnight to take them.

**john** · 06-18-2005, 06:20 PM

There are 4 red 12ga wires connected together. See diagram. One goes to the junction block on fender by batt, One to alt One to regulater and one to block on firewall. Plus a 18 ga B/W fused wire for ammeter if so equipped. It might be easier to find another wire loom for eng if yours is hacked up.

R@nger · 06-19-2005, 06:33 PM

Ok here some pics

Alt

Where the alt wires go

Wire pile up...there are 4 wires here but one of them is like brown or black I think and its under the tape.

This is to the right of my radiator next to the headlight.

**john** · 06-19-2005, 07:59 PM

WOW it looks like it was hacked up when it was rewired for the alt on pass side with long pump and later eng. those should be the alt wires in the first pic. It should have at least a 12ga wire from pos batt to terminal block on the fender. Those red wires in the diagram are tied together inside the loom on drivers side I cant tell what goes where from the pic but I would definatly get another loom and start over. You will still have to rewire for the pass side alt. I think they do make looms for your setup. Possibly painless or a board vender. Good luck John

R@nger · 06-19-2005, 08:46 PM

Ohh so the alternator is originally supposed to be on the drivers side?

EDIT: The engine is a 77-79...it was swapped shortly before I got it...could that be the reason the alternator is on the passengers side and not the drivers?

I REALLY wish the previous owner

would have done his homework and done the job right.

06-17-2005, 11:36 PM	#1
R@nger Psalm 23 Join Date: Apr 2005 Location: Utah Posts: 360	Alternator electrical question Ok well at the moment I have my fan shroud and fan off and I'm painting the fan shroud..can't stand the yellow, half painted mess that it has been since I got the truck . Anyways with all the extra room I changed my alternator belt. This got me looking at the HORRIBLE wiring going on in my engine compartment. My question is, where are the wires from the alternator supposed to go? I looked at the wiring diagram posted in the FAQ section but its to complicated because my wiring is so messed up I can't even tell whats what. Right now they have the power from the alternator going to a 4 way pile up where it there continues through one wire across the radiator and into the fusebox maybe???...and then they have a wire connected directly to the positive battery post going across the radiator and again possibly into the fusebox???...its a horrible mess. Just a little explaination of what wire goes where in the engine compartment would be a huge help...thanks . __________________ 71 GMC Fleetside C15(cab), 3/4 ton, 350, Holley Street Avenger 570cfm carb, TH350 trans, Leaf-springs, 2WD. "Peter are you sleeping on the job? No I have a bug in my eye and I'm trying to suffocate him." - Family Guy Last edited by R@nger; 06-18-2005 at 12:11 AM.

06-18-2005, 02:19 PM	#3
R@nger Psalm 23 Join Date: Apr 2005 Location: Utah Posts: 360	Yeah I'll post some today...it was to dark lastnight to take them. __________________ 71 GMC Fleetside C15(cab), 3/4 ton, 350, Holley Street Avenger 570cfm carb, TH350 trans, Leaf-springs, 2WD. "Peter are you sleeping on the job? No I have a bug in my eye and I'm trying to suffocate him." - Family Guy

06-18-2005, 06:20 PM	#4
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	There are 4 red 12ga wires connected together. See diagram. One goes to the junction block on fender by batt, One to alt One to regulater and one to block on firewall. Plus a 18 ga B/W fused wire for ammeter if so equipped. It might be easier to find another wire loom for eng if yours is hacked up. Attached Images __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/

06-19-2005, 06:33 PM	#5
R@nger Psalm 23 Join Date: Apr 2005 Location: Utah Posts: 360	Ok here some pics Alt Where the alt wires go Wire pile up...there are 4 wires here but one of them is like brown or black I think and its under the tape. This is to the right of my radiator next to the headlight. __________________ 71 GMC Fleetside C15(cab), 3/4 ton, 350, Holley Street Avenger 570cfm carb, TH350 trans, Leaf-springs, 2WD. "Peter are you sleeping on the job? No I have a bug in my eye and I'm trying to suffocate him." - Family Guy Last edited by R@nger; 06-19-2005 at 06:35 PM.

06-19-2005, 07:59 PM	#6
john member #16 Join Date: Dec 1999 Location: Yuba City Ca. Posts: 3,618	WOW it looks like it was hacked up when it was rewired for the alt on pass side with long pump and later eng. those should be the alt wires in the first pic. It should have at least a 12ga wire from pos batt to terminal block on the fender. Those red wires in the diagram are tied together inside the loom on drivers side I cant tell what goes where from the pic but I would definatly get another loom and start over. You will still have to rewire for the pass side alt. I think they do make looms for your setup. Possibly painless or a board vender. Good luck John __________________ john http://67-72chevytrucks.com/vboard/showgroups.php board vendors http://www.flickr.com/photos/1745471...7602865984234/ Last edited by john; 06-19-2005 at 09:42 PM.

06-18-2005, 07:20 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	pics?

06-19-2005, 08:46 PM	#7
R@nger Psalm 23 Join Date: Apr 2005 Location: Utah Posts: 360	Ohh so the alternator is originally supposed to be on the drivers side? EDIT: The engine is a 77-79...it was swapped shortly before I got it...could that be the reason the alternator is on the passengers side and not the drivers? I REALLY wish the previous owner would have done his homework and done the job right. __________________ 71 GMC Fleetside C15(cab), 3/4 ton, 350, Holley Street Avenger 570cfm carb, TH350 trans, Leaf-springs, 2WD. "Peter are you sleeping on the job? No I have a bug in my eye and I'm trying to suffocate him." - Family Guy Last edited by R@nger; 06-19-2005 at 10:13 PM.



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