Sympton:
86 MCSS, started normally, idled smoothly, the drive required headlights on
-during the drive when engine dropped to idle speed the choke light came and all the lights dimmed momentarily and all gauge needles twitched.
-at idle speed voltage was at 13V with quick dips into the 8V range, lights dimmed, idle became rough and the tach needle twitched upwards
-at idle with headlights on and turning was activated, voltage dipped to 8V, all lights dimmed
-increasing idle speed to 1500 all lights and functions behaved as normal
I assumed there is a ground problem, maybe bad battery or possibly the alternator or voltage regulator.
Following the KISS principle, the easiest check was to start at the battery.
Solution:
Yep...both battery terminals were slightly loose.
Thankfully it was an easy fix but the twitching tach needle had me baffled
Conclusion:
This shows even someone with many years experience servicing electromechanical equipment he is not immune to tekky boo boos
86 MCSS, started normally, idled smoothly, the drive required headlights on
-during the drive when engine dropped to idle speed the choke light came and all the lights dimmed momentarily and all gauge needles twitched.
-at idle speed voltage was at 13V with quick dips into the 8V range, lights dimmed, idle became rough and the tach needle twitched upwards
-at idle with headlights on and turning was activated, voltage dipped to 8V, all lights dimmed
-increasing idle speed to 1500 all lights and functions behaved as normal
I assumed there is a ground problem, maybe bad battery or possibly the alternator or voltage regulator.
Following the KISS principle, the easiest check was to start at the battery.
Solution:
Yep...both battery terminals were slightly loose.
Thankfully it was an easy fix but the twitching tach needle had me baffled
Conclusion:
This shows even someone with many years experience servicing electromechanical equipment he is not immune to tekky boo boos
