car is sluggish, only with headlights on....

[Bikercmbc]

OK, not my car, but a D that i'm working on. just recently added a new alternator and the output voltage of the new alternator at the battery is correct: 13.2v at idle, but on the cluster reads just above 8v no alt light on.

car run and starts fine at idle. when you accl. past 3/4 throttle car boggs down and will no longer accl.
with the running lights on when you accl. past 1.2 throttle the car will bogg down and will no longer accl.
with the running lights and the headlights on when you accl past 1/4 throttle is will bogg down and no longer accl. as soon as you turn off the headlights you have power up to around 3/4 throttle.

i'm thinking along the lines of bad ground, not enough voltage for spark, FYI its a Stage 1 knology car, or wiring issue due to cluster not reading properly and just wierd electrial issues in the cluster.

any help, experience, or ideas to start narrowing down the issue will be appreciated.

[Jonathan]

no alt light on.

Does the alternator/battery warning light come on during the ignition sequence? i.e. key turned to accessories.

[Bikercmbc]

yes, dave at MW states this is normal with the alt, which was from dmcmw.

[Bitsyncmaster]

You should be getting about 14.5 volts with the engine above idle. If your dash gauge shows 8 volts than you mush have a bad connection. I would guess the ground and 12 volt feed lines under the rear shelf board would be your first thing to check.

[Bikercmbc]

the ones that go directly to the battery/ starter?
check for excessive resistance? kinda makes sense the starter is brand new but will click like there is not enough amps to turn over, sometimes, not all the time.

[Rich W]

How old is the battery? Was the battery "run down" previously, prior to the alternator being recently replaced?
Even if the battery is relatively new, when was the last time battery was "fully charged" with a battery charger?

Grounds are always a good thing to check and to make sure they are cleaned on a regular maintenance schedule.

[Bikercmbc]

It's been a little while since fully recharged but always is disconnect when not in use. I'll get the battery recharged. Im leaning more towards bad grounds, or high resistance with in cable/harness

[Bitsyncmaster]

You pull those top clips that hold the rear net on the shelf and the back board will come out. Then you can see where all the black (ground) and brown (+12) wires bolt to. Check that those connections are clean and tight.

[Bikercmbc]

ok, ill take a look at them, I just had those out a few weeks back when the whole interior was out, should have checked it then.

[mluder]

You should be getting about 14.5 volts with the engine above idle. If your dash gauge shows 8 volts than you mush have a bad connection. I would guess the ground and 12 volt feed lines under the rear shelf board would be your first thing to check.

+1
I just corrected a slew of issues with my car by simply cleaning and tightening up the ground on the inside of the rear bulkhead behind the passenger seat.
Check out this thread...
http://dmctalk.org/showthread.php?9589-Is-Everything-Alright

Here's a post from that thread with a pic of the ground location...
http://dmctalk.org/showthread.php?9589-Is-Everything-Alright&p=142012&viewfull=1#post142012

Cheers
Steven

[Bikercmbc]

excellent information, I will give that a look at next week sometime and will post back on my findings

[DMCMW Dave]

Clean or replace all the fuses too.

[Bikercmbc]

Well just an update on this problem. Cleaned all grounds and fuses added dielectric grease to all connections after cleaning them and secured tightly. Still had an issue. Today got my dvm and with car running only got 12.3v, no charging from new alternator. Checked signal wire from cluster, no voltage at all. Next removed binnacle and started checking grounds and power at all the connector terminals. Then I found this: 27568

Luckily I had another cluster and used that circuit board and the cleaned all connections and made sure all the bulbs were good. Now I got a correct cluster and charging system!!! 27569

This should take care of the sputtering with headlight since I was driving only on battery