plee3 64Olds

Ok, this is my issue:


I purchased a 64 Cutlass with a 76 355 Cutlass engine in it. the generator light is illuminated on my dash and the alternator is not charging the battery. The alternator has 3 wires running from it. there are 2 14 gage wires running to the fire wall. there is an 8 gauge wire running to the inner fender well. Im thinking the 2 wires running to the firewall is not connected to the correct wires. I need some advice on how to make sure the alternator is wired up correctly. What wires should be hooked up to what??? remember, I have a 64. The engine is a 76.

joe_padavano

The engine is irrelevant. What alternator do you have? External regulator? Internal regulator? A photo would help us give you useful info.

plee3 64Olds

Ok. Im a newbe! LOL! How do I post pics on here???

plee3 64Olds

Let me upload all pics. I will have them shortly.

joe_padavano

Once you have typed in your post, scroll down before hitting Submit and you'll see a box for Additional Options, which includes Attach File. Note that there's a max file size limit, so you may need to resize the photos.

plee3 64Olds

Ok, here we go. I know I got a mess of wires there. I have to go behind some one else to higure out what's going on! I hate troubleshooting like that! LOL



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plee3 64Olds

there is a junction point on the inner fenderwell drivers side. I see that the 8 gauge power wire goes there. Also, I was told that the box on the firewall that says Delco Remy is the voltage regulator. Could that be the culprit??

joe_padavano

OK, the alternator is an internally regulated 10SI or 12SI. The voltage regulator on the firewall needs to be bypassed if it isn't already. I can't tell from the photos if the alternator wires actually connect to the HEI terminal or not. In any case, here's how your car SHOULD have been converted to use that alternator:



In the diagram above, the red wire from the old voltage regulator terminal 3 runs to the junction block on the horn relay. The brown wire from the old regulator terminal 4 goes to the GEN light on the dash. I would also lose the crappy spade connectors on the alternator and get a proper connector and pigtail from NAPA or other auto parts store.

Tony72Cutlass'S'

Hey All,

I have a similar Alternator i believe on my '72 Cutlass with a 350.

My question is, does it matter if two connectors that fit onto the alternator (labeled 1 and 2 above in Joe's diagram) reversed? The previous owner had a similar setup (spade connectors) and i was looking to switch to a proper connector as shown above. Does it matter if the two terminals are reversed?

Thanks a bunch!

Cheers,

Tony

- 1972 Cutlass 'S' in Bamboo Yellow

joe_padavano

Very much so. That's why the stock connector only attaches one way.

Tony72Cutlass'S'

Okay great, thanks!

Would a similar wiring diagram as the one you posted need to be followed? The alternator I have is the same part number as from a 1983 Firebird (DELCO 10SI; 63 AMP)

Thanks again,

Tony

- 1972 Cutlass 'S' in Bamboo Yellow

joe_padavano

Yup. That diagram applies to any GM car originally equipped with an externally regulated alternator that is being converted to an 10SI or 12SI.

Tony72Cutlass'S'

Oh great! Thanks, i'll print that one out for my records.

Cheers,

Tony

- 1972 Cutlass 'S' in Bamboo Yellow

plee3 64Olds

excellent diagram! I understand it! Ok, Like you stated, it does make a difference if the 2 wires are switched. as im looking at the diagram, would that be the front of the alternator or the rear?? oh, 1 more thing, whare is the horn relay located??

joe_padavano

The diagram is from the rear, but the casting is marked with #1 and #2 anyway. This is why you want to get the correct plug.

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It's the box on the driver's side inner fender with the threaded post and the battery cable going to it. Just connect the red wires to that threaded post. I did exactly this conversion on my 62 F-85 wagon.

plee3 64Olds

Ok, you stated that "the red wire from the old voltage regulator terminal 3 runs to the junction block on the horn relay. The brown wire from the old regulator terminal 4 goes to the GEN light on the dash." but the diagram is showing something different. It shows the red wire connecting to the white wire and the brown wire connecting to the blue wire. then the blue and white wires are connecting to the alternator.

joe_padavano

I was talking about the OTHER ends of those wires, which are not shown in that drawing. Your car has obviously been monkeyed with by someone so you need to verify that those wires actually go where they are supposed to if you use them. Otherwise you may introduce new problems without knowing why.

plee3 64Olds

You know what, you are correct. I just ordered the wiring diagram for the 64. At least that will give me a solid base on these electrical issues. I will keep you posted! I Thank for your assistance! You really helped me out!

Tony72Cutlass'S'

I just found that pigtail at my everday auto parts store (Canadian Tire) for 2.99, heck of a deal for finally getting my alternator to charge my battery right, heh.

Cheers,

Tony

- 1972 Cutlass 'S' in Bamboo Yellow

plee3 64Olds

I came to the conclusion that the alternator is bad. I did the rewire and the alternator still wasnt charging the battery! I removed the alternator and had it checked. it failed! I purchased a new one< installed it and it worked like a charm! I just have wiring issues inside the car. Thanks for all the assistance everybody!!

plee3 64Olds

Now that I have a charge going to the battery, I would like to know how to bypass the external voltage regulator in the firewall. Do I cut the 4 wires and tie them together?? Please leave feedback.

joe_padavano

You already have bypassed it. Simply remove the regulator and tie the remaining pigtail up neatly. Don't go cutting anything.

plee3 64Olds

One more question, I still have a GEN light on the dash when my car is running. I have the new alternator installed. I have a 4 Gauge wire from the alternator to the horn relay. I have also have the red wire (I picked up the pig tail like you suggested) connected to the 4 Gauge wire. (same as running it to the horn relay) Now where does the white wire go?? I remember you stated that the brown wire from the external regulator was responsible for the GEN light. Do I hook the white wire from my alternator to the brown wire from the external regulator?? Im sorry if I am asking alot! LOL!! Im almost finished with the charging situation.

joe_padavano

Yes.

plee3 64Olds

I have started the painful rewiring process! LOL!! Its a mess! (well, not really) I still have a gen light on the dash when the car is runningI have studied the diagram and this is my understanding:

1. On the voltage regulator, the brown wire has a dotted arrow leading to the blue wire. Then the blue wire runs to #1 terminal on the alternator.

2. On the voltage regulator, the red wire has a dotted arrow leading to the white wire. Then the white wire runs to #2 terminal on the alternator.

3. The big 4ga wire from the alternator runs to the horn relay.

What else am I missing here?? If someone has some real pics to post, it would really help. Thank you gentlemen for all of your assistance!

joe_padavano

Let's start with basic troubleshooting.

1. With the engine off, key in the RUN position, disconnect the plug from the back of the alternator. The GEN light should be off. If not, this wire is shorted to ground somewhere.

2. Engine still off and key in RUN, check the red wire in the connector for power using a test light or a voltage meter. There should be battery voltage (about 12V). If not, there is a break or bad splice somewhere in this wire.

3. Engine still off and key in RUN, connect a jumper wire from the white wire in the connector to the battery +terminal. The GEN light should go off. If not, there is a break or bad splice between the connector and the GEN light.

Run these tests and report back.

plee3 64Olds

Thanks for the steps Joe! That helped! I physically removed both wire harness from the firewall. WOW! WHAT A MESS! The red wire was melted to oher wires So somthing was shorted! I removed both harnesses and cleaned them up pretty good. I wired everything back and to my suprise, the gen light goes out when the car is started! Great! Im going in the right direction! I unplugged all of the spark plug wires and I cant ge the car started again. I will keep you posted on further events!

plee3 64Olds

Day 2 of troubleshooting. I loose 12V going to the HEI Distributor. Since The 2 big red wires were melted< i decided to go ahead and order ALL wire harnesses (dash, engine starter, front lights, rear lights) all new wire is needed. I will udate you on my progress. Your assistance really helped me out. I have the wiring schematic so I should be ok. My engine and trans is fine. Just alot of wiring issues.

compedgemarine

if you order new harnesses in stock form they will probably have a resistor wire going to the coil. this would need to be replaced with a regular wire. if you talk to the people you are getting the harness from and tell them you have an HEI most offer a harness that is already converted for electronic ignition

Tony72Cutlass'S'

Hey Joe,

Just wanted to say thanks for the diagram you supplied earlier in this post, i hooked up a 10SI alternator from '83 in my 72 Cutlass and it's charging without fail at 14+ Volts. Pretty awesome!

Cheers,

Tony

joe_padavano

Glad it worked for you.