help! lights pulsate and wipers speed up

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racerdude5

racerdude5

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As the output for my alternator increases, my headlights and other lights begin getting brighter and begin pulsating faster and faster. My windshield wipers also increase in speed. Can someone help me?
 
racerdude5 said:
Its a new one made by standard motor products
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what year mopar we talking about? Try a Eletronic reg, new design. Not the one from the 80s but a retro fit one. Ck voltage. Could be a bad bulkhead connector. Ive seen that before.
 
As stated I sounds like a bad connection at the bulkhead connector
 
Would it be one bulkhead connector in particular? How does a bad connection cause that, please educate me. Thanks guys.
 
I had a similar pulsing and I changed the reg the alt and bypassed the amp gauge still nothing finally when I tore out my harness to do a wire kit I found that two wires were just slightly melted together on the interior side of the bulkhead connector .I cant remember exactly which 2 it was off hand but I still have the harness in the shop and will check tomorrow if you need
 
Sure sounds like a voltage regulator. Do not overlook the fact that the voltage regulator, although new, could be faulty. Who among us has not installed a new part that did not fix the problem and then spend hours testing everything else because we knew it couldn't be the new part. Use a tester to se what the volts are at different RPMs.
 
racerdude5 said:
Would it be one bulkhead connector in particular? How does a bad connection cause that, please educate me. Thanks guys.
Click to expand...

A bad connection can cause the regulator to not sense the voltage in the system correctly and constantly wrongly adjust the voltage.

Ground quality is HUGE with these cars. (Battery to body, and battery to engine are critical)
You would be amazed at how a few electrical and lighting system changes can make a huge difference.

These cars were not all that good in the wiring department when new, but there are things that can be done about a lot of it.
Getting as much of the amp load off the cabin wires helps a ton, and the ammeter bypass and headlight relay kit solves a lot of that.
Basically it uses your current switching and wiring only to activate the relays then the relays and new larger wire then handle the amps load for them.

A squareback alternator puts out a little more at idle.
The ammeter bypass is almost mandatory.
A relay kit for the headlights makes a huge difference
An electronic flasher unit (instead of the bi metal amp hog factory style.)
LED lighting for everything but the headlights helps a lot.
(example; normal brakelights use about 8 amps of power and my LED's use about one half of an amp)
That leaves about 7.5 amps free for other things, like wipers and headlights.

These four things even done one at a time but in this order will make a major difference for each one you do.

My lights don't dim at idle or when the brakes are on anymore, and my wipers and signals no longer slow down at idle due to these changes.
Pretty much everything that uses a lot of amps is off my cabin wiring and moved to relays.
The devices work better and your switches will last a lot longer due to the reduced load.
 
The surest way to check this out is to use a voltmeter and check the battery voltage at low idle and fast idle with the battery fully charged. And measure the voltage between the battery + and the alternator output at fast idle. With that data, it will be a lot easier to help you. And a voltmeter will be a worthwhile tool on these older cars; you can troubleshoot a lot on them with one.

As mentioned, check the grounds all over; the new regulator may need a bit paint scraped off and the points where it attaches cleaned with a wire brush. The pulsating lights point to that (or some other poor connection) being a good probability. And the attaching screws may need to be replaced with bolts, or larger lag screws if the attachment holes are wallowed out.

BTW, with the original system, some change in wiper speed and headlight brightness is normal; we can't see just how much it is on the i-net. But the pulsating is abnormal.
 
Alright so I took some sand paper to the washers, and the surface of the voltage regulator that contacts the little threaded inserts on the inner fender and sanded those a little as well. Then I took some sand paper to the washer, the surface of the head, and both sides of the ground strap and it seemed to make it better. I think it's still far from fixed but that was definitely an improvement. Thanks guys!
 
terminals p and k were melted together on the inside side of bulkhead
 

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Thanks for the pics. UPDATE: So the lights don't pulsate so much at low speed and they dont get brighter anymore as rpms increase. However they still pulstae when above 1500 rpms
 
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