W107 560SL Battery Light Question

[rewillia]

For some reason, my battery light (instrument panel warning) illuminates for brief periods, i.e. 1 minute when making sweeping turns, such as when turning through an interstate exchange ramp at moderate speeds of 40-60+ MPH. Otherwise it (warning light) never comes on and there are otherwise no indication of electrical problem. The battery is secure, in its enclosed case, all wires tight and properly secured.

Any idea what could be causing this? The warning light does goes out after I am through the curves and continuing on my way...stumped/

The light does not come on when making slow turns or otherwise and I am experiencing no electrical problems, starting, running, etc.

[RadioTek]

I'd check out a few things:

1) Check for loose wires and connections in the circuitry from the alternator to the instrument cluster. When you pull the instrument cluster to check, add an additional ground lead from the cluster to a good ground on th ebody metal. Things could be shifting a little, and causing poor electrical connections. Also check that all connectors are seated correctly on the back of the cluster.

2) Alternator condition, including the brushes (an easily replacable module). If the belts or the belt tensioner are not right, it could do this sort of thing, or if the bearings or brushes are worn.

3) Motor mounts and the subframe mounts. How old are they ? They could cause unusual shifting of the engine if bad.


Just a few wild guesses,
Scott

[abiby]

After a good bit of thought as to what could be influenced with the centrifugal force of a fast turn, my best WAGs match with a couple of Scott's... Alternator brushes and/or belt tension (alternator mounting).

[rewillia]

Dear RadioTek and Abiby.

Thanks. My problem is only when I turn hard and fast, i.e. at speeds of 50+ MPH, usually happening at connecting interstate ramps and does not always happen just sometimes. Otherwise it never comes on (battery warning lamp/indicator), my belts in good order, all wires harnessed as OE and I so not suspect the alternator to be the source as stated, there appears to be no other electrical related issues. Charges fine, starts, etc.

Regarding your recommendations, the charging curcuit, alternator, etc all seem to be working fine and all sub-frame/motor and trans mounts are solid and in good order.

Its a weird one (the problem) I know but I do not suspect that it is related to my alternator brushes, frame mounts or bushings...

All the same, thanks for your input & advice.

[RadioTek]

Like i said, jusat a few wild guesses. A few things to eliminate. My line of thought was to look at what would move under the stresses involved in a turn; that would be where we should go in trying to troubleshoot this. Maybe there's something rolling around in the footwell that rolls into the fuse panel? (tounge in cheek suggestion)

Is there something loose in the wiring harness, a connector that is a little flaky, or a wire that is a little tight in its' routing? Check the field wire to the alternator (usually a green wire from the ignition switch) and the connector. Wiring problems most often occur at the connectors. Then check for wear points or pinches.

Please keep us up on how you're doing on this. Trying to troubleshoot something over the net is really just a collection of variously educated guesses at best.

Good luck, and happy hunting
Scott