Lights/wipers/radio mystery miswiring??

[Rweiss6]

Need help please, weird electrical issues in my beloved 1981 Spider

Sometimes when starting , if I hit headlight or wiper switch they don’t work, the battery light goes on and radio goes off.
This may resolve in a minute or so, and doesn’t always happen. Sometimes car starts, and all normal.
Other day, this lasted for two approx 20 min rides, when I got home and tried half hour later was normal

Today, was normal for good while, then got home and happened again. Hit Light or wiper switch , neither works, red batt light goes on, radio goes off. Turn switch off, light goes off and radio right back on.

I have tested battery, it’s 12,7 volts , with engine idling its 14.2 approx I bought new alternator last July from Auto Ricambi , I’m pretty sure this wasn’t happening before , maybe something to do w install ???

Where to look ????

This forum has been very helpful , have learned a lot here , really appreciate it.

[gschwab]

Not sure I can help a lot here, but the ignition switches are notorious for going bad due to being overloaded. If there's no good contact, it can lead to all kinds of issues. Maybe that's something you might want to check into.
Good luck!
Gunther

[18Fiatsandcounting]

Poor battery cable connections would be another possibility, including the ground strap from the battery negative to the body of the car. Make sure the cable/body connection is clean and tight.

-Bryan

[Rweiss6]

I checked battery connections and ground , they are very tight and secure

I unplugged and replugged pigtail of ignition switch bunch of times to be sure contacts are good, I think they are

Frank at AutoRicambi has been helpful before, suggested I turn the fuses around and around to clean the contacts , I did , they “looked” pretty good ( I know that may not matter) , anyway I spun and made sure each fits snugly.
He suggested I add headlight relay , when they’re back in stock. I will do so, first relay install for me.
Maybe I should do same for wipers??

Any other ideas where to look? I know this is a weird one, also not all the time , often normal , sometimes lasts very short while at startup. Very rare to persist, but has happened too.

[wizard124]

Sounds like corrosion or frayed wire to me. You might have good voltage at fuse block or at ignition switch but when you load up the circuit, it can't carry the amps required.
Radio turning off, wipers not responding, red alternator light are all indications.

Test wire resistance to find the problem.

[Rweiss6]

Thank you, that makes sense. Need instructions please , how to test wire for resistance ? Which wires ?
I have vmeter and test light , learning more each time there’s an issue

I see headlight wires’ plugs on each fender, I’ve looked because I will install relays when avail.
I’ll follow instructions carefully and post it here

[wizard124]

I would start with the ignition switch. Test resistances between the power tab and the run tab. Compare this to the power and start tab.

Then check the wire which powers the fuse panel. Take a Dremel brush and clean the fuse contacts; ensure they are tight to the fuses. Clean the fuse contacts. Hopefully, it is something simple.

[Rweiss6]

I used sandpaper on all 12 contacts and fuse ends and made sure they were snug.
I believe it has made a difference , in past couple days has only happened couple times , and for mere few seconds. Used to take up to minute or less to normalize, except one day when it lasted all afternoon.

I bought new fuses , wondering should I just put 12 new ones in ?

I think ignition switch contacts are ok, I unplugged and replugged few times
What else to do ? thank you for this help

Wonder if H/L relay will help, once autorambi has in stock. They have a video w clear instructions on install, very helpful for rookie like me