Gauge/Battery voltage question.

[400sbctruck]

My 1997 does something I dont like.

Anytime I use accessories such as blinkers, cargo light, basically anything electrical- the needle jumps down.

Usually I would think weak battery etc but I have a pretty fresh AGM on here.

Anyone else 96-98 have similar? I might try fishing a new wire to it and see if things get better.

Its either that, or maybe it was
Built with barely enough alternator....

[Kudzupatch]

Have you checked the voltage to make sure the gage is wrong or right? Would be much simpler.

[DuallyDave]

What does the gauge read normally?
What does it drop down to?
your gauge had nothing to do with your battery. It deals with your charging system. I would take it to your parts store. They with test it for free.

[Mr_Rich]

That sounds like a normal condition. Turn on your headlights, heater fan high, windshield wipers, and stereo and then tell us what the voltage is. Maybe then we can say you don't have enough alternator...

[400sbctruck]

3 volt drop from blinker...
Headlights wipers blower motor cargo light all on 12v-ish.

Freakin blinker takes it to 13v from 14.5ish by itself.

With everything electrical on radio on too like 14 right on the money.

The blinker thing i know its stupid, just dont like it.

These gauges have a pin contact like the old ones? Deoxit and if its still there let it be I guess.
Battery checks out strong, so does alternator.

[speedygonzales]

Always noticed under full load what you were talking about. After I did the body lift and put electric fans on, it was worse than ever. The fans pull something like over 30 Amps.

Some time in the last couple of years, I replaced the alternator with this 150 Amp job
http://www.summitracing.com/parts/pwm-38206/overview/

Then I ran another positive cable from it to the battery another ground strap from the battery to the frame of the alternator. All is happy now.

If you haven't already done so, remove and clean all the cables at the battery, frame and alternator.

You can also experiment with adding cables to certain connections temporarily with jumper cables. Like the grounds and such to see if that might add a little umph.

Remember that over time as connections degrade, the amount of current needed to cross those connections increases.

[400sbctruck]

Thats such a simple solution it almost has to be the problem.

Today im going to go ahead and beef up engine grounds and bat-alt cable.

Originally Posted by speedygonzales

Always noticed under full load what you were talking about. After I did the body lift and put electric fans on, it was worse than ever. The fans pull something like over 30 Amps.

Some time in the last couple of years, I replaced the alternator with this 150 Amp job
http://www.summitracing.com/parts/pwm-38206/overview/

Then I ran another positive cable from it to the battery another ground strap from the battery to the frame of the alternator. All is happy now.

If you haven't already done so, remove and clean all the cables at the battery, frame and alternator.

You can also experiment with adding cables to certain connections temporarily with jumper cables. Like the grounds and such to see if that might add a little umph.

Remember that over time as connections degrade, the amount of current needed to cross those connections increases.

[speedygonzales]

Any update?

[400sbctruck]

Originally Posted by speedygonzales

Any update?

After cleaning bat and alt and ground connections i moved on to deoxit the cluster connections.

Of all stupid things, the indicator light for the turn signal went bad immediately. After replacing it, i have "normal" needle bounce as you would think it should act.

I think the connections were barely doing their job, though the bulb "could" have contributed.

After all that, the blinker causes about half the voltage drop it used to.

Been busy painting my frame and engine bay, fwiw the duplicolor rust repair spray is awesome...I naval jellied and used it topped by sandable primer...


...my Rock auto stuff (delphi cap/rotor and Ac plugs) came in today and so did the accel wires....so tomorrow is tune up day.


This weekend Ill go get some BFA cable 2awg or bigger to update the puny stock wires. Ill update as to how that affects the instrument cluster as it may help a tad. May even buy a 3.00 roll of wire and fish it to the ammeter for S&G.

[400sbctruck]

On a different note-did you note any mpg changes from cluth fan - to electric - to electric fans plus BFA alternator?

I had the power steering variable assist probs and disconnected the pump connector for Caddy steering. .7 mpg average drop in a month. Next time I need a pump Im thinking 92-95 to get less assist.

Tune-up may push it back up a little but Im at 16.7 where I
Was at 17.4(both average # over several weeks). The 3.42 helps on the highway but around town it can be a touch of a hog.

[speedygonzales]

I have 17" rims and 35" mud tires. So the best I can do going down hill with the wind is 12MPG.

I'm Jonesen to do a RamJet intake and change out the entire fuel injection system. I think with the right controls, I can crack 15MPG. I have the Ramjet cam in the engine now so that doesn't help the MPG either.