Low voltage w/ new batt and alternator

[DemonNeno]

Well, I'm starting to get aggrivated with my gremlin that wont give up! The car wont build more than 11.5-12V regardless of RPM. The battery has been replaced as has the alternator. The battery terminals were also replaced. I even threw on a new alternator accessory belt since the last one looked like it spent the last 10 years laying ***** in the desert.

Now, should I look into possibly ground problems with chassis ground for the alternator? The starter terminals all looked to be clean enough when I changed the rod bearings, so I'm 99% positive that's not my problem. Here's another question that worries me, would ANY ground on the car that is a weak link cause such a problem, or would this strictly be a result of a poor batt/alt/starter ground? Any other advice would be very much appreciated.

 

[SHOZ123]

My guess is a bad regulator or alternator. You should have over 70% or your rated amperage at 1500 rpm assuming the battery needs it.

 

[DemonNeno]

The regulator is on the alternator, correct? The battery is a Napa badged exide orbital battery w/ a 350 amp load test, or so it claims. Regardless to such, powering a 750watt amp, 2 12" subs running off of it, and the 6 speaker system dims lights and cuts the radio to cut out (sound cuts on and off but the head unit remains a bit dimmer yet lit).

I tried taking out the radio and re-splicing wires/soldering them all and covering them w/ a decent amount of electric tape. This was done because i recently installed the head unit and discovered the dimming issue. So I imagined a possible loose power wire or poor connection elsewhere, but all looked well and is insured with a soldering job for that extra ummph.

See the emergency section of Gen 1 & 2 Help and Maintenance for assistance with the supreme demon! GEEZ! Did this month start off on the wrong foot, or what?!

 

[SHOZ123]

Most regulators are internal since the 70s. If you do not have ~14V at 1500 rpm and ALL electrical devices running you have a bad alternator/regulator or bad connections. You could have bad cables.

 

[DemonNeno]

so a voltometer test at the batt and at the starter solenoid revealed 14.04V... Still getting 12V to the gauge, head unit is dimming/stopping when at idle as the voltage continuously drops. Bought another alternator and tested it, no cigar. Cleaned up my ground wires to the starter, cleaned up the alternators ground and power supply. Nothing... Any more ideas?! This is REALLY annoying. :

 

[SHOZ123]

Check the connector at the engine fuse box and big alternator wire..

 

[BlackOnBlackATX]

this is really puzzling. how old are the battery wires? what about the ground on the alternator? is it in good shape? what kind of guage are you using to test it? you might need to try making new grounds. have you had any starter problems? and also, do you know that the right pulley is on the alternator? did this just start with a new alternator or was it with the old one too?

any ground could be a weak link like you stated. let us know what happens. good luck.

 

[DemonNeno]

Well, the battery cables look great. I took apart the terminals, wire brushed them, along with all the mounting points (even used a grinder wheel at any reachable ground points). I'm not sure how old the wires to the battery are as I bought the car roughly two years ago. I can't imagine these are the problem, however, seeing that I have 14.04V at the starter solenoid?

Never had a starting problem. The starter never stuck, never failed, and never made any erractic noises. Every crank has started it as if the car was getting more juice than necessary. Thank god!

As for the grounds, the only thing i'm not 100% sure is COMPLETELY clean would be the alternator brackets (which i'm told also help ground the alternator to the motor) although they looked fine when installing the new alternator.

Now, sorry if this sounds crazy, but I CAN NOT find any type of fuse block beneath my hood! The only fuse block I do have is under the dash (by the ebrake) and everything seems to be fine at that point. I just purchased a MAC Voltometer just for this purpose.

Alternator wire seemed to be fine. The car is now losing more and more juice on the daily basis! At one point, i was roughly at 12.5V and am constantly at 12V now. It's getting so bad, my radio will not allow me to play it any loud than volume # 14 (Alpine Model# 9827) out of a # 35 max range. Any louder and face unit begins to flicker like a candle and the sound completely cuts out. Uninstalled the radio, no difference in the volts, all wires are still soldered together (i did this to troubleshoot after installing the new alt).

Now for a question... The 2 prong alternator connectors do NOT have a circuit ground, correct? Only the cable with the ring eye that is screwed against the alternator is the ground?

 

[DemonNeno]

Back at 13V... still draining, though.

So i fixed a chunk of the problem. The Alarm system had apparently burnt through a power wire that somehow was shorted out. Now that I've unplugged the alarm and thrown it away, i need to clean up the mess of wires. BTW, i was reading 13.4V-14.2V at the alternator. However, I'm still losing a lot of power from the radio, but the problem could very possibly be the rest of the wiring or a problem with the alternator... Will keep you all posted!

The guage is an AutoGuage (in-car guage) which happened to also have loose connectors. After tightening it up, I read an additional .3V-.7V depending on the actual feed it was recieving. I *think* my overall charging system output increased after removing the guage, but This will only be a temporary thing as I'm in the process of wiring the guage to a

I'm getting a CRAZY fuse/relay clicking (like an repetitive on/off clicking noise of a relay) ONCE in a while when I shut the motor off but keep the accessories on. SOunds like it's coming from the fuse block, but it could also have somethign to do with my ignition **** alarm thingie..

Radio now plays much better, however still breaks up at higher volumes (MUCH higher volumes than before.. i can almost completely turn it up now... but that's just not good enough! lol)

I'm glad this much has been solved.. it's amazing what a meter and test light can do for your car.. oh yeah and people to lend the tools to you!