Topic: Low RPM's at idle

[95jeeper]

We i have my set of 4 kc lites on with headlights, stereo,  and electric fan running my engine likes to bog down. So i installed a mean green high output alternator hoping to fix the problem "and plus i needed a new one" but the engine still bogs down. Is this normal or is there a solution to this problem

[Bounty Hunter]

Have you had the battery tested?

[95jeeper]

yeah its good and i had the alternator tested too... Everything tested good. They told me my amps were high but that's the new alternator.

[tjjohn]

With all those acc running at once the alt will pull a lot of power away from motor even more so al idle. Try adding another battery or thicker gauge cable.

[BlueFlu]

Are you running a relay with the KCs?

[neale_rs]

Energy is energy, when the system requires more electrical energy the alternator gets harder to turn.  No way around it.    The suggestion to run relays and bigger cables and wires should help to keep losses due to wire resistance (heat generation) to a minimum. I would think though that the computer should automatically adjust (give it more gas) to keep the idle speed constant.  But maybe it just doesn't, as evidenced by the fact that a special sensor is used to up the idle speed when using the power steering at idle.

[sharpxmen]

just a thought - there might be deposits on the throttle body idle valve.

I wonder if there is a way to tap into the P/S switch to up the idle when there is too much load on the alternator (maybe driven by the alternator driver wire to engage over a certain voltage). Anyone seen/heard of this before? I remember reading somewhere that the L6 computer has a pin and when it is put at ground (or 12v not sure) was increasing the idle rpm - this was for police vehicles to run additional lights, computer and accessories, not sure if this was automagic or you had to push a button (i would think that was auto).

[neale_rs]

 That´s most likely what the PS pressure switch does...just ground a pin on the computer or send some voltage to a pin.  A mechanical solution would be a hand throttle like is used when an on-board welder is installed.

[sharpxmen]

when i'm done with my other projects i'll look into this - would be handy to have a threshold on driven by the alternator load to increase the rpm. in my case when i go camping and drain out the second battery it almost dies the next morning when starting to charge - not sure what the difference is though between on/off (i mean in rpm with no load) or it would just keep the rpm at 1000 for example regardless of the load (i mean is it a set position of the idle control valve or it tries to dynamically adjust the idle to match a higher set rpm)