Jump to content

Recommended Posts

As your aware I’m not using the voltage regulator at all. Ive been using this system with a 60 amp alt for a few years.  I just installed the 140 amp alt, so I guess it’s too early to tell if things were to melt. 
 

Since you guys have brought up the inadequacy of the 10 ga alt wire. I’m a little freaked and don’t want to have any concerns, especially if I have a cruise tomorrow night and it’s about an hour away. So, I wound feel a little more comfortable if I change that 10ga one wire to a 4 ga.
 

It seems this has brought m to a charging issue. So, if I change the alt wire to 4 ga that should balance things for now until I address the headlight issue. 
So..... Should I change that now???

Share this post


Link to post
Share on other sites

Good idea to change out that charge wire on the alternator before driving it much more.  The wire length you need looks short from the picture.  You can probably get away with 6 ga. wire so it doesn't look like your alternator is connected with a battery cable.  There are plenty of charts and tables online the list wire size amperage and length rating.

This kit from Painless Wiring is rated at 190 amps and it includes 6 ga. wire.  It actually looks like a nice kit.  Might be worth looking at for later.  I installed a complete Painless Wiring harness in another project, 1956 Ford F100 pickup, I think they have nice products.

https://www.painlessperformance.com/wc/30700

Share this post


Link to post
Share on other sites

Thank you 1969_Mach 1 for that information. It does look more stable then the Jegs one I have.  You mention that my wire looks too short, but wouldn’t short equal less resistance. I would think that’s better. 
 

I might have come to that bridge that I’ll have to replace the 51 year old wiring this Winter.
 

Because of Covid, Car Shows are starting to pop up all over and the weather is right for cruising!!!!!

Thanks again all for your guidance!

Share this post


Link to post
Share on other sites

I guess I wasn't clear.  It looks like only a short length is needed.  Absolutely nothing wrong with that.  Resistance to current flow in a length of wire increases as the length of wire increases.  That's partly why when batteries are moved to the trunk larger size cables are needed.  So for this and most automotive wiring situations, shorter is better when it comes to function. 

Share this post


Link to post
Share on other sites

Had a good cruise last night, about 200 cars up and down the street.

Now gave an 8 ga alternator wire. Last night with headlight on it read 13.5 . The drive home at night was about an hour, read 13.5. Without likes it’s 14+.

Checked wires when I got home, none were hot, either was the alternator,

should I change the Alternator wire from 8 to 4 gauge?

Someone on the Facebook Cruise page posted my car

 

D05ED648-351B-4C0C-BE05-3C589ACA883A.png

Share this post


Link to post
Share on other sites

So the facts are that a #8 copper wire has 0.00063 ohms per foot at 68 degrees.  Let's say your wire is 3 feet long from the alternator to the battery.  That is 0.00189 ohms. If you have lights, fans, and everything on  and drawing 100 amps, that is a voltage drop of .189 volts in the connection between the alternator and the battery.    There are also voltage drops in the connections on each end and at the fuse. And then there is also a voltage drop on the negative wires to the battery. 

One thing you can do is meaure the voltage drop from one end of the wire to the alternator to the other.  Use clipleaads on your voltmeter and measure from the bolt on the back of the alternator to the battery terminal.  Start your car, and turn on lights, engine fans, and heater fan inside the car.  If that voltage exceeds 1 volt, that is your problem.   Also measure the voltage between the ground terminal on the alternator and the minus terminal of the battery.  Maybe you have dirty connections on the ground wire from the engine block to the firewall?  These tests will prove it. 

I also have to wonder about the use of a 60 amp fuse with a 140 amp alternator.  If this fuse has not blown, that tells me you are never using more than 60 amps. 

I would not worry about the lights for now, figure out the charging problem.  Adding the relays on the lights is a great idea, and can be done later.  You have different things contributing to the problem.  Alternator wire, ground wire connections (maybe),  weak headlight wire connections, headlight wire voltage drops, etc.  

 

Share this post


Link to post
Share on other sites

How do you check amperage at the alternator?

FYI- I’m not using the voltage regulator, just the 1 wire from the Solenoid to the Alternator

So, shorten the 1 wire. Should I change it to the 4 gauge? 

All grounds are with a 4 ga wire. (1) Ground from block to firewall,. (2) ground from battery to radiator support. (3) Ground from battery to Alternator, from there to block. 

 


 

 

Share this post


Link to post
Share on other sites

Shortening or changing to a 4 ga. alternator charge wire isn't necessary.  A 6 ga. charging wire should be fine since the the length you need isn't very long.

Grounding:  Battery ground to engine block.  Then engine block to body somewhere near where a motor mount bracket attaches to the body.  4 ga cables for both of these should be fine.  I also run a ground strap from the back if the passenger side cylinder head to the firewall.  That ground could be smaller than 4 ga., 6 or 8 ga. would be fine.

But again, I'm not convinced the alternator is working correctly.  What brand alternator is it?

Share this post


Link to post
Share on other sites

A lot of parts supplier shops have an alternator load tester.   You can take it in and they put it on a spinning contraption and hook a load up to it to measure the voltage as the output current increases.   Maybe you could send it back to the manufacturer to have it tested?  Shipping makes that difficult.  

Maybe take it to a shop to measure the current when the fan and lights are on?   That should be a 2 minute test if they have the clamp on ampmeter. 

I would hate to have you purchase a new alternator and find out the problem is something else. 

Have you checked the wire from the starter relay to the battery?   This could also be a problem, even though it is not likely. I have seen these poorly contructed and causing an issue.   Turn on the car and run all the fans and all the lights.  Measure the voltage at each end of this wire.   Put the + lead of a voltmeter right on the lead terminal of the battery and the - of the voltmeter on the wire going to the alternator from the starter solenoid.   This will give you an idea if the voltage drop is in this wire.   It is a slim chance, but I have seen these fail.  I also know that, if everything is working correctly and the car is running, there should never be any current in this wire.  All power the car needs to run everything should come from the alternator. 

Share this post


Link to post
Share on other sites

I thought of something else. From what I understand, your negative wire from the battery runs directly to the mounting bolt of the alternator, is this correct?    Measure the voltage drop in this wire when you have the fans and lights on, as I discussed above.  Put a voltmeter + on the center lead terminal of the battery and the - of the voltmeter on the case of the alternator. With all fans and lights on, this better be under 0.1 volt. 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...