Ignition light blinking

[boxboy]

I got my truck out on the road today. I have recently fixed a burnt section of the printed circuit, but I am sure I did a clean job with no crossing over to other lines. Anyway, as I was driving all of a sudden the ignition light started blinking. It would go off when I pressed on the brake or turned on the turn signal, but blinked faster as the engine revved faster, and slower as we moved to idle. What is the meaning of this? Any ideas? Everything else seems to be working great, for once.

[datzenmike]

Loose fan belt

Loose wiring on alt.

Regulator not properly grounded to fender.

[ggzilla]

Early Datsun have IGN lamp; later ones CHG lamp. Either way about the alternator and voltage regulator.

[ggzilla]

By the way, my CHG lamp has been doing this from time to time for the last 1-1/2 years. After starting the engine, sometime the light comes on or flashes, but eventually goes off. The alternator checked out OK, so I'm waiting for it to get worse so I can tell exactly what is wrong.

 

A couple of weeks ago I picked up a spare used alternator with internal regulator, so I'll just swap it in when/if it gives up.

[paradoxx]

By the way, my CHG lamp has been doing this from time to time for the last 1-1/2 years. After starting the engine, sometime the light comes on or flashes, but eventually goes off. The alternator checked out OK, so I'm waiting for it to get worse so I can tell exactly what is wrong.

 

A couple of weeks ago I picked up a spare used alternator with internal regulator, so I'll just swap it in when/if it gives up.

 

does this happens to you with the stock regulator? or you have already changed it to newer one?

[ggzilla]

It only happens occasionally, for weeks it won't happen. Yes it is the stock alternator & regulator. It is a 1972 regulator.

[datzenmike]

Stock regulators are mechanical and use relays and contacts like points to turn the alt. charge on and off. Is senses under and over charge conditions and opens or closes contacts to adjust for it. The battery tends to smooth out the on off pulses. I imagine when they get old there will be some flickering. They could do this for years and maybe never go bad. I also switched to a newer IR alt from a 720. It was fine for a couple of days and the light stayed on so I converted a KA 90 amp and ran with it. The 720 alt had never been run in years and was old. I took apart and one of the brushes was much shorter than the other and both were worn. This is almost certainly the problem with it. I had about 7 of the 720 alts I threw out, now I wish I had kept them for parts.

[boxboy]

I checked the wires and replaced some others. Seems to be working correctly now. Except now my temperature gauge quit on me. Starts moving when I start the truck, but then goes off about a minute later. May just be an old wire there too. I don't know. Gas gauge is working fine.