150 Amp Alternator... Yes or No?

[B2G707]

Within the last few months the electrical on my car has started to diminish. First I noticed the radio would cut out, out of no where. Then at night my head lights would be really weak, so I purchased a new battery. Still my radio would cut off, head lights at night would be weak and eventually my car started dying at night would I hit the brakes at a stop light.

Long story short, I bought a 60 amp alternator which many people are saying it isn't strong enough to power my car along with my 2 10" subwoofers in the back trunk.

So I purchase the Tuff Stuff 130 amp alternator. Do you think 130 amp would be sufficient? Because people are telling me I should get a 150 amp alternator.

What do you guys think?

 

[704406]

Have you done the Bulkhead wiring repair and bypass yet? If not you will likely melt your main power feed from the alternator to the gages as well as possibly other wiring with a 130-150 amp alternator.
Even if you have done the repair I don't think I would run that high an amperage thru 45 year old wiring.
The symptoms you are describing sound like wiring connection issues. Have you tested the alternator output at the back of the alternator, then at the battery to see what your voltage loss thru your wiring might be?
If not do that first, get the voltage and amperage numbers so you aren't guessing at the problem.

 

[Adam]

I completely agree with 704406; you need to bypass the ammeter, it is a fire hazard. Most likely you will have to repair a melted firewall connector; I would run the alt output directly to the battery; add a new voltage regulator; and power the headlights thru relays. Sounds complicated but is easy and inexpensive.

Check out these links:
Vintage Chrysler electrical repairs and updates

Daniel Stern Lighting Consultancy and Supply

These articles are long on the why, but the recommended mods will easily solve your problems with minimal cost and labor.

 

[B2G707]

Have you done the Bulkhead wiring repair and bypass yet? If not you will likely melt your main power feed from the alternator to the gages as well as possibly other wiring with a 130-150 amp alternator.
Even if you have done the repair I don't think I would run that high an amperage thru 45 year old wiring.
The symptoms you are describing sound like wiring connection issues. Have you tested the alternator output at the back of the alternator, then at the battery to see what your voltage loss thru your wiring might be?
If not do that first, get the voltage and amperage numbers so you aren't guessing at the problem.

Thank you very much for responding. I need this kind of info, I been dealing with this issue for so long and it just got worse. First people suggested I buy a new battery but it still happened, then said I should buy a new alternator and it still happened. My car car would start showing signs of week electrical issues. Then would die out on me. Very frustrating to say the least.

So prior to changing my alternator do a bulkhead wiring repair first? I don't know to much about these classic cars, but I wanted to relay what your suggesting to my mechanic. This Saturday is my appointment to bring in my car.

 

[B2G707]

I completely agree with 704406; you need to bypass the ammeter, it is a fire hazard. Most likely you will have to repair a melted firewall connector; I would run the alt output directly to the battery; add a new voltage regulator; and power the headlights thru relays. Sounds complicated but is easy and inexpensive.

Check out these links:
Vintage Chrysler electrical repairs and updates

Daniel Stern Lighting Consultancy and Supply

These articles are long on the why, but the recommended mods will easily solve your problems with minimal cost and labor.

Thank you for this! I just emailed the link to my mechanic.

 

[B2G707]

I completely agree with 704406; you need to bypass the ammeter, it is a fire hazard. Most likely you will have to repair a melted firewall connector; I would run the alt output directly to the battery; add a new voltage regulator; and power the headlights thru relays. Sounds complicated but is easy and inexpensive.

Check out these links:
Vintage Chrysler electrical repairs and updates

Daniel Stern Lighting Consultancy and Supply

These articles are long on the why, but the recommended mods will easily solve your problems with minimal cost and labor.

So if I were to redo my wiring. What exactly would I be buying? A whole knew Under-Dash Wire Harness?

 

[Adam]

You can easily unplug the firewall connectors on the engine side. You will see where the wiper harness, and others plug in. The melted terminals will be obvious.

You do not need a new harness. You just need to repair any melted connections, pack them with dielectric grease and plug them back in. Then run a big wire (with fusible link) from the alternator output lug to the battery or positive starter terminal. This will reduce the full amperage running through the firewall connectors.

Your ammeter will not be accurate after this, but it can be changed to a voltmeter later on.

The headlight relays use the original wires to activate the relays, so you just need power from the battery or alternator to the relay, a good ground wire, and new wires to the headlight plugs. You will then have great headlights.

 

[Adam]

I also power dual electric fans thru a relay. To hide my relays, keep the wires short, and get them out of the engine heat, I mounted them behind the driver’s side headlights. This is a nice short run to the battery. Additionally I put all the wires inside shrink tubing and ran it along the inner fender, with the other wiring harness. Hard to notice that way.

 

[Adam]

Basic relay info, for those that are considering this mod: most relays have 5 pins that are numbered.
87= Full power output to the device, headlights, fan, amplifier, etc.
87A= not normally used.
86= from switch, headlight, fan temp sensor, etc.
30= Full power in, from battery or alt output.
85= good ground.

The original switch wire (86) is adequate to activate the relay. Use heavier gauge wire for everything else.

Relays come with different amp ratings, usually 30 amps. You can run the low beams off one relay by running two wires from the 87 terminal, or you can get a dual 87 terminal relay (not 87A).

Same goes for the high beams. So minimally you would need two relays, one low beam, one high beam. A 30 amp relay will easily handle two headlights, with room to spare.

Relays are pretty cheap, maybe $8 with the pigtail. Buy extras; don’t buy Chinese if you can help it.

 

[B2G707]

You can easily unplug the firewall connectors on the engine side. You will see where the wiper harness, and others plug in. The melted terminals will be obvious.

You do not need a new harness. You just need to repair any melted connections, pack them with dielectric grease and plug them back in. Then run a big wire (with fusible link) from the alternator output lug to the battery or positive starter terminal. This will reduce the full amperage running through the firewall connectors.

Your ammeter will not be accurate after this, but it can be changed to a voltmeter later on.

The headlight relays use the original wires to activate the relays, so you just need power from the battery or alternator to the relay, a good ground wire, and new wires to the headlight plugs. You will then have great headlights.

So do you think after doing all this, my 60 amp alternator would run my car including sub woofers with no problem? I shouldn't experience my radio cutting off? Headlights dimming and most importantly my car dying out at the light or stop signs at night?

Reason I ask, if my current alternator is sufficient enough I'd like to return my new alternator I just purchased. Save some money ya know!

 

[Adam]

If it were me, I would try it with the 60 amp unit first and if you are satisfied then return the 130.

I think the 60 amp will be ok, as long as you are not running the amp full volume, ac/heater, hi-beams, wipers, etc. Headlights probably draw 15-20 on hi-beam, so if your amp is 40 or less you should be ok to run them both at the same time.

 

[moparleo]

Do the free stuff first. Clean ALL of your connections and GROUNDS. This is the number one problem with almost all classic cars. As said before use plenty of Dielectric grease on all connections. Why ? The grease is non conductive and seals the connections from water and air. Oxidation ( corrosion) is caused by the exposure to air(oxygen) which is why metal doesn't rust when painted but will if the metal (containing iron) is left bare, exposed to the air and moisture. The better and cleaner the connections are, the more current that can travel through them, which will require less amperage total in the system.

 

[704406]

You said you had been dealing with your electrical problem for a long time and it's getting worse.
A very clear indication of wiring connection problems getting worse, the higher the amperage going thru the system the more heat builds up, the worse the connections get.
Adam is correct, pull the engine harness at the bulkhead you will likely see evidence of melted, or deformed connections.
Also look under the dash at the fuse box area, you can move the fuse box out of the way and look at the back of the bulkhead connector. you will likely see melted, deformed wiring at the main power feed from the alternator.
All power from the alternator goes thru the bulkhead thru the amp gauge then back out to the battery.
It's not uncommon to lose 1-3 volts between the alternator and the battery, that means huge resistance, resistance means heat buildup, heat buildup means melted connections.
It's important to check at the alternator output lug and at the battery for voltage/amperage loss.
Do what's been suggested and you will repair the charging system and make it safe!

 

[B2G707]

In addition to what we already have discussed. After purchasing a new 60 amp alternator(from before) and new battery(from before) this is what happens when I try to start my car.

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Think its safe to say its bad wiring?

 

[B2G707]

Would this be the correct wiring kit for my car?

 

[aussiemark]

Just clean and repair what you have to at least confirm the problem I am sure you can repair what you have without the need for an aftermarket wiring harness, it's like pulling all your teeth out and getting a full set of implants when all you need is a couple of fillings and a descale.

 

[B2G707]

Just clean and repair what you have to at least confirm the problem I am sure you can repair what you have without the need for an aftermarket wiring harness, it's like pulling all your teeth out and getting a full set of implants when all you need is a couple of fillings and a descale.

Even though my wires is old and brittle looking? Yeah I get it, trust me I'm really not in the position to buy a new wiring kit. Specially I found out it cost like $2500 to install.

As far as cleaning and repairing my existing wires. How do I exactly do it?

 

[Adam]

If you do not fix the issue you have, you might fry that $563 wiring harness. And having completely re-wired two trucks I can assure you of three facts:
1. It will NOT be painless
2. It will be much more WORK than fixing what you have
3. It will COST much more because it is very labor intensive.

 

[Adam]

Have you unplugged the bulkhead connector and looked at it? Let’s determine what the problem is...

From the engine side, follow the wiper motor wires down to the connector. Squeeze the tabs on the sides and unplug all the harnesses. Take a good look at both the plug and sockets for melted areas. You can spray the terminals with contact cleaner if they need it. Get some dielectric grease and grease all the terminals before plugging back in.

If you find melted wires, we can discuss how to best repair those... but in short the damaged terminal(s) can be removed from the connector housings on both sides so repairs can be made.

 

[Adam]

Btw, at most you would need is a 14 circuit harness, unless you have electric windows and door locks. These aftermarket harnesses are nice, but they do not have bulkhead connectors. This means you have to cut each wire, add a terminal to it and plug it into the correct spot... see the problem here, same possibility of corrosion or melted wires (until you bypass the ammeter).

Optionally, eliminate the bulkhead connectors and run each bundle of un-cut wires to their destination. You will need to deal with the big square hole in the firewall and wrap or shrink tube the wire bundles to keep it from looking like spaghetti... these harnesses would have a voltmeter wire, so either way you will need a voltmeter eventually.