low battery gauge readings?

[95suburb]

recently, my battery gauge would drop from 14 to 12 and redline at 9 when I turned on anything such as turn signals, radio, ac etc. So, I cleaned off any corrosion I saw and I purchaced a new set of batteries that put out 940 ca a piece and the gauge went back up to 14 but would occasionally drop and just stay around 9-12 with anything on. So, to hopefully fix the problem I purchased a new 105 amp alternator but, i'm still having the same problems...any ideas on wut could be wrong with my trucks electrical system would be really helpfull..


...1995, 2500 6.5TD 4x4 166,000 miles

[grancito]

Are your lights dim? Your engine is obviously starting so it is not a battery connection or engine ground, but could be the body ground or a bad connection at the starter motor between the battery lead and the main power lead to the rest of the system. One other is a bad connection to, or inside the ignition switch, especially if the head lights are not dim.

[Chevylover]

I got the same problem on mine the last 3 month. First, checked all grounds, than checked both Exide Maxxima batteries -> one 885 CCA and the other 915 CCA. So it must be the alternator. Bought a new one, installed and problem solved. So i decided to check the old alternator. With NO brushes it can't give enough volts. They where down to the hole which is in for installing.

Now i got 14,7 volts directly after starting and about 14,4 if engine is hot/warmed or lights on.


Cu,
Sven

[95suburb]

my outside lights don't dim, but the inside lights will. such as the clock on the radio, you can see the light on that dim if I turn up the radio or turn on the ac or even throw a turn signal on. the truck starts right up to which is wierd if i have low battery gauge readings...I have a brand new wire from the started to the battery that I replaced when I replaced the starter, so could the other wires possibly be bad?

[grancito]

the problem is from the ignition switch, be it the switch or the connections/ cables to it, see ignition switch / guages post today.

[surreysinner]

When i changed the factory wire from alternator to battery to a larger wire and better connectors it fixed my problems and works great now.

[grancito]

95suburb, you have a connection that is allowing almost no current to flow, as your drain for radio volume, or indicators is very low.

[w_huisman]

When i changed the factory wire from alternator to battery to a larger wire and better connectors it fixed my problems and works great now.

What did you use to cover the hot wire connection on the back of the alternator?

[Husker 6.5]

What did you use to cover the hot wire connection on the back of the alternator?

When I did an upgrade to a 100 Amp alt on a friend's '68 Cutlass with an 8 guage wire from the alt to the battery, I used the 90* boot for a sparkplug wire that attached to the HEI distributor I had laying around. The boot slid perfectly over the wire, and the open plug end popped right over the nut and stud on the back of the alternator. Looked totally OEM, and the boot is a great insulator.

Hope this helps.

Husker 6.5

[zarg2@comcast.net]

check the cable that connects the 2 positive terminals for any corrosion or looseness. the voltage gauge reads from the battery on the driverside and will show low voltage even if the alternator tests ok. another symptom is intermitent no starts since the starter doesn't have enough current to spin the engine. i've wasted money on an alternator and starter before i figured this out. also check the battery terminal bolts for wear. i had to replace one on the passenger side battery, the threads were worn so the stacked cables didn't make a good connection giving a low voltage reading. i could only find the proper length bolt from the gm dealer. hope this helps.


zarg

[zarg2@comcast.net]

i forgot to mention that all the electrical bits [ lights,radio,heater fan etc.] run off the driver side battery, so they will dim, run slow etc. even though the batteries and alternator test ok individually. good luck!

zarg

[Husker 6.5]

95suburb:

Like I said in a previous post in another thread on the same subject: CHECK YOUR GROUND CONNECTIONS!! ALL FIVE OF THEM! BOTH ENDS!

Two battery negative to engine block (at least one is good, as the starter works) on each side of the engine. One engine to body (behind pass. head) One engine to frame strap, one frame to body strap. You obviously have a poor body ground as evidenced by your low batt voltage gauge reading and fluxuating interior lights with any current draw such as the turn signals.

Current must flow in a complete path from pos., through a device, then to the neg. battery terminal. It must utilize a body, chassis, or engine ground to do so. The cab electronics grounds through the body, so I would begin with the most obvious, the engine to body ground behind the passenger head, as the engine is the only thing connected directly to battery negative, and everything else ground connects to the engine:D !

From what you have described, you do not have a battery positive connection nor altenator problem, forget about them and concentrate on the negative:D, as your obviously have a current return problem.

Your dash lights dim with the turn signals as they are trying to ground through them!!

Husker 6.5