Electrical Electrical woes have me confused

[mikeah]

Hi all,

I just recently swapped my 1988 Mustang Alternator as it didn't seem to be charging the battery, etc. I've swapped it in successfully, wired it up, and confirmed when the car is running I'm seeing around 14.25V or so which to me indicates the battery is getting a steady charge from the alternator.

After driving around the neighborhood a bit today to get better with stick shift, I stalled out (still learning standard -- car was passed down from the loss of my father). Tried to turn it over and there was no charge it seemed. I used my battery jumper and was able to get the car running again until I got it home (it did take a while on my jumpstart which is odd -- usually this gives the charge immediately).

When I got home and turned the car off, I noticed all the interior lights etc, were out and not illuminating in any fashion. I tried to jump it again with my jumpstart and this time it seemed like there was no power making it to the cabin or starter. I even tried taking my multimeter to a few fuses in the interior fuse box and I'm seeing no voltage on any of the fuses (but in the engine bay I see 13-14v at the battery).

I looked at the infamous starter solenoid and I couldn't quite tell if anything was wrong with it, but I also don't see any fuses in or out of the solenoid FWIW so I'm not leaning towards a fuseable link being bad unless I'm missing something.

A few minutes ago I went out to the car, rolled the power windows up, and attempted to turn it over and it lost cabin lighting again and it's back to behaving like there's no power. I'm aware it's charging, but what would explain the nearly total loss of electric as I'd anticipate there's some residual.

At this point I doubt the battery is the issue, but I'm wondering where my electrical issues are likely stemming from? Part of me is leaning towards rewiring the whole alternator wire harness, but the fact that I see 14v when the car is on and 13v or so when I turn it off would indicate that it's getting a charge.

Any ideas? Thanks in advance and happy to provide pictures, video, or clarification wherever I can.

 

[Potomus Pete]

You seem to be able to use a multi meter so you should'nt have any problems getting to it. Was it going good before all of this?? What about the alt. new from the store??

 

[Potomus Pete]

Sorry about your father. A bigger reason to get this car going. Just keep reading up on these cars. You probably should get familiar with the No Start Checklist it's a great way to get to know your car. If you plan on keeping this car your going to have to get through these problems in the beginning till it runs well Welcome to Stangnet

 

[General karthief]

You may have a bad connection, start at the battery and check cables and grounds, key on and key off.

 

[mikeah]

Thanks all for the tips and kind words. This car is basically my lasting memory of my father as we restored it once before back when I was in middle school and it's been in our family since he first got it. Keeping this car alive and restoring it back to its former glory is definitely my intent .

Some progress today when I threw the fully charged battery back in. The interior power worked for a bit and then it died. I took a look again at the solenoid this AM and I did notice a possibly faulty fuseable link, but I am not sure that it's actually faulty (cracked at the fuseable link label bit). The green wire seems to be the one I'm suspecting is faulty.

Voltage at the battery is looking good, going to try to see why I am not getting voltage to the interior, but I'm going to debug this wire and a few others further.

 

[Potomus Pete]

What are your plans for driving this car. It could be a loose wire so maybe have somebody crank it while you fool with wires. It's constant until you get it the way you want it. I would look for an old school Mustang guy that lives in your area. If you find on they should know how to fix it quick. When I got mine a found a guy that figured mine out permenantly. He even opened my computer and changed out the capacitors that were known to fail. Lastly how about a picture of dads family car so we can see what your dealing with.

 

[mikeah]

Electric is usually my strong point with cars (sound systems, etc), but these fusible links are admittedly new to me.

Y'all are gonna think I'm an idiot, but I noticed after swapping both those fusible link wires that it was still intermittent. Needless to say my father in-law and I noticed the battery terminal for the positive side is cracked at the bolt when we troubleshooting further.

I guess it really is always the simplest of things. It makes sense that I was seeing the voltage with the multimeter at the battery, but not down the line really.

Gonna go grab a new battery terminal and wire it up and I think we'll be in business!

Here's a picture of the mustang currently for your enjoyment and another from back in the day prior to him and I restoring it and having it painted.

EDIT: Found one of us working on the car and my bike at the same time (when I was a kid haha).

 

[mikeah]

It's fixed!

New terminals for both (just to be consistent) and we're back to everything working as expected. I feel like a fool for missing this initially, but I guess my multimeter was just consistently hitting the battery posts, so I missed the lack of voltage going consistently down the line.

If anyone is feeling like they're having this issue, don't skip this check like I did. Seems like something I should have checked thoroughly off the bat. Lesson learned haha.

 

[Potomus Pete]

The General was right as usual. That's a great car.

 

[General karthief]

Basics first grasshopper, basics