ammorri2 Posted September 22, 2013 Share Posted September 22, 2013 My voltage gauge bounces between 12 and 16 while idling at startup. As soon as I give it gas, the voltage spikes to the max reading the gauge will read. This started happening after I cleaned the fusible links with a brass wire brush without disconnecting the negative battery cable. A spark shot from the link terminal through the wire brush into the bracket that holds the fusible links. I thought it was the voltage regulator that was fried in the alternator, but after installing a new alternator, the problem persists. Quote Link to comment Share on other sites More sharing options...
ammorri2 Posted September 22, 2013 Author Share Posted September 22, 2013 Sorry, the cars a 1978 280z. Quote Link to comment Share on other sites More sharing options...
SlowRob Posted October 1, 2013 Share Posted October 1, 2013 '78 should still have an external voltage regulator. Quote Link to comment Share on other sites More sharing options...
z240 Posted October 1, 2013 Share Posted October 1, 2013 Actually the 78's were the first to have an internal regulator. 78 FSM EE-21 If you happen to have replaced it with an earlier model that requires an external v-reg, this may be the cause. Quote Link to comment Share on other sites More sharing options...
SlowRob Posted October 1, 2013 Share Posted October 1, 2013 Your short shouldn't have done anything, nor should just cleaning the links. Check all the major connections; Links, Alt, Battery, making sure everything is good. Put a meter on the system - engine running - and see if it confirms the gauge. If it does, then it's the probably the regulator. If the meter shows a steady ~13.8v, then it's your gauge. I suspect the latter. You should be ale to check at the battery. Nominal charging voltage for most alternators is ~13.8v. The battery will buffer the reading to some extent, but if the alternator is full fielding, you'll see something far above 14v. Quote Link to comment Share on other sites More sharing options...
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