odd electrical problem dealing with headlights and radio

[cenok is family]

ok, so i'm THINKING my 3g install might be the culprit, i've been reading the "3g alternator install: a how to" thread roland posted and i've realized how ghetto i did the install. i didn't run any 4g wire anywhere, i just got the alternator with factory pig tails and did some ghetto splicing. and my block ground is still the braided strap going from the back of my driver's side head to the firewall. anyways, my problem is anytime i turn my headlights on, my radio cuts in and out when my rpm's are low. pretty much anytime i press in the clutch and the rpm's drop down to idle. it's REALLY annoying at night when i want to listen to music and i come to a stop and it cuts in and out until i bring the rpm's back up. what do you guys think? j-rich? thanks

oh yeah, i asked this in roland's thread but i might as well ask it in my thread as well....when running the 4g ground wire, i just need to replace the braded ground "strap" that runs from the back of my driver's side head to the firewall with the 4g wire, correct?

 

[samickguy15]

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Sounds like low alternator output. I would upgrade the wiring anyways. As far as ground wires, you can leave the existing and add to them or you can take them off and replace them. The more grounding the better.

 

[cenok is family]

Sounds like low alternator output. I would upgrade the wiring anyways. As far as ground wires, you can leave the existing and add to them or you can take them off and replace them. The more grounding the better.

yeah i'm going to. so you think my alternator is bad as well?

 

[jrichker]

If you work at Radio Shack, spring some $$$ and buy a DVM. Look for 13.8 -14.2 volts at 650-725 RPM. Most auto parts stores can check the alternator on or off the car. Since your wiring may be questionable, pull the alternator and have them check it off the car.

Don't cheap out on the wiring, use a 4 gauge power feed with a 125-150 amp fuse . You need a 4 gauge ground from the engine block to the chassis ground by the battery. See the photo for the chassis ground point.

Picture courtesy timewarped1972

 

[cenok is family]

If you work at Radio Shack, spring some $$$ and buy a DVM. Look for 13.8 -14.2 volts at 650-725 RPM. Most auto parts stores can check the alternator on or off the car. Since your wiring may be questionable, pull the alternator and have them check it off the car.

Don't cheap out on the wiring, use a 4 gauge power feed with a 125-150 amp fuse . You need a 4 gauge ground from the engine block to the chassis ground by the battery. See the photo for the chassis ground point.

Picture courtesy timewarped1972

yeah i have a DVM. so as far as the wiring goes, pretty much unhook it all, and run a 4g power wire with a fuse in it from the alt. to the solonoid and then of course the 4g ground from the block to by the battery. i bought a 32" 4g battery switch cable that i'm gonna run as the ground. i'll get some pics up asap so maybe you can see what i'm talking about with my current wiring. thanks a ton

 

[cenok is family]

ok so today i installed my 255lph pump, everything went smoothly except i got some gas in my eyes. that sucked. i also had my alternator tested and it passed. so i proceeded to upgrade the wiring to 4g. i ran a 4 gauge wire from the post on the alternator, around the front of the radiator along side the headlight harness, down under the battery tray into a 250w ANG style fuse then another foot of 4g out of the fuse to the battery side of the solonoid. i also put a 4g ground wire where you said to jrichker. battery meter is staying over half way now, doesn't move much, even with the headlights on, but my radio is still cutting out! not near as bad anymore, but still doing it none-the-less. now i'm kinda stumped. maybe the way my radio is wired? i dunno though because it didn't use to do this. i don't remember if it started doing it before or after the 3g upgrade, i think before, actually. so what now?

 

[cenok is family]

ttt

 

[cenok is family]

View attachment 363881

 

[jrichker]

Use your DVM to get a real measurement of the voltage while the engine is idling. Measure the voltage across the battery: you should see 13.8 -14.2 volts, and 14.0 volts or more at 1000 RPM.

 

[haoleboy72]

Did you ever figure out what your problem was? My car is experiencing similar problems. I drove my car to work and it was fine. I drove it 4hrs later and if I hit the lights, wipers or tapped the break pedal the radio would cut out. Gauge shows above half way the whole time. I will probably check car with DVM when I wake up.

 

[cenok is family]

no i still haven't figured out the radio thing. my battery is new and good (i did a load test on it), my alternator is good, and i just completely rewired my alternator using a 4ga power wire and ground and i know i did that right too. i'm thinking its either the wiring for the radio or the radio itself. i'm leaning more towards the wiring though.

 

[haoleboy72]

That's not the answer i was hoping for I just think it's weird that it just started happening out of the blue, i haven't done any work on the car lately. I guess I will start with ground wire, radio wires then check out the fuseable link. I'm hoping it's something not too intensive