Any answers on this electrical gemlin?

Sunroof · 10-25-2004, 04:37 AM

I ran a thread a few weeks ago about my problem whereas my lights flicker. Many responses claimed it was the voltage regulator.

Let me advance the problem a step further and say that the flickering of all lights (headlights, dash, etc) goes away after a few miles of warm-up. How do you account for that? I replaced my original voltage regulator with the latest version about a year ago. My alternator was rebuilt about six months ago, but the voltage regulator was not replaced as often recommended.

I have no problem with the charging system, the lights stay bright, but the flickering can make your eyes go nuts!!! What happens during the warm up that takes the problem away? And what is the best way to test the voltage regulator to see if it indeed the culprit.

Thanks

Bob
73.5T

Joeaksa · 10-25-2004, 05:10 AM

Bob,

Please take a digital VOM (volt ohm meter) and give us some voltage readings! I had exactly the same thing and it was my regulator breaking down and letting the unit go to 16+ volts. That was the filiment in the light bulbs going from the normal of 14.5 to way more than they like.

In your car its not as important. In the later cars it can fry an fuel injection computer very fast. That said, its still not good so make sure what your voltage is reading then pls get back to us.

JoeA

Early_S_Man · 10-25-2004, 12:57 PM

Bob,

Is you current regulator a metal-cased version, or one of the later plastic-box wonders??? I didn't think the plastic-box version showed up until 1974 models. The schematic for the 73.5 models shows a conventional relay/resistor regulator that can be adjusted after the cover is taken off.

This is a case where an analog Voltmeter gives better information than a digital ... unless the digital has a high-speed sampling data-logging mode.

An old Simpson 260 or 270, Triplett 630-series, or Weston 660-series meter will give you an idea of how much variation between the peaks is going on ...

An oscilloscope, either storage or conventional could also tell you immediately whether the problem is the regulator. A scope trace pic could be useful to illustrate the problem for all ...

As far as the regulator ceasing the flicker after warming up ... that would be a thermal-normalization problem indicative of a marginal problem when cold that resumes proper operation after warming up to normal operating temperature ...

At this point my assumption is that the rgulator needs to be adjusted or replaced. If you still have you original regulator ... it is possible that its' contacts could be cleaned and re-adjusted, and that might solve the problem!

Sunroof · 10-25-2004, 02:03 PM

The regulator I purchased was a Bosch #0192062007 that was still metal housed but much more compact then that giant box that came with the vehicle. It was according to the parts folks the OEM replacement. Interestingly, the other night, the lights kept on flickering even after warm up.

Can my worn turn signal mechanism or headlight switch be a culprit?

I do not have access to a meter and the cost of the regulator replacement ($44.00) is really cheaper then a meter.

Any further feedback is appreciated.

Bob
73.5T

Joeaksa · 10-25-2004, 02:53 PM

Warren,

Boy are you bringing back memories. I still have a Simpson 260 in the bottom of the toolbox and use it from time to time. Good meter...

Bob,

Yes, the price of a good meter is not cheap but it should last you a lifetime and be used on various things, not just around the car. Its a very good investment and something that should be in every mechanic's toolbox. Harbor Freight has them for $9.95 if you are hurting for funds.

JoeA

RoninLB · 10-25-2004, 04:46 PM

I'd also check for AC ripple at the alternator output.

john walker's workshop · 10-25-2004, 06:02 PM

get a plug that fits the cigarette lighter and attach a voltmeter to it. then you can drive around and when the lights start to flicker, you'll see what the voltage is doing.

klaucke · 04:16 PM

Originally posted by Early_S_Man:
"I didn't think the plastic-box version showed up until 1974 models."

My 74 has a metal cased version, which I believe to be stock. Maybe it's not, but something to ponder. The VR that the parts stores try to sell me has a 3 prong connector, my car has individual wires. It looks like the one in this pic (which is from another thread)

Pic from this thread, the pic above is of another 74 911