I gots a Pulse

[Mr. Land Yacht]

I've had this problem for a little while now...getting annoyed by it.

when I'm between like 600-1500 rpm, all of my lights pulse with the engine rpm...once it gets above 1500rpm, its pretty solid.
when it did this before, it was the fuse for my fog lamps...and that got disconnected when I replaced the red cable for the battery...just havent hooked it up yet.

is it maybe a bad regulator in the alternator or something?

it has done this on and off since I bought the car in Nov. 04...I have gone thru....2 alternators...I'm on my 3rd.
still has the same battery in it that it did when I bought it...an Interstate Battery.
I havent had any trouble with it...other than the corroded cable...and sometimes I've left my headlamps on and drained it..its happened a few times.

any ideas?
the only thing I'm thinking of is doing the "3G Conversion" that Bobert did to his old Merk...sure did keep the lights bright and smooth after that.

[P72Ford]

Same problem here. I'm waiting for it to catch fire and burn to the ground. I replaced the external VR and it seemed to quell the pulsating for a while. Now its back at it again. I have several other alternators, one looks like its new. I may put one on if the condition worsens. Not sure what to do. If you've changed alternators, maybe you should try the external VR, if your car even has one. Mines on the drivers fender. Little metal box. Some cars had internal regulators in the alt. If thats the case with you, then its probably not the regulator as you would have gotten a different one with a different alt.

[Mr. Land Yacht]

mine has the VR in the Alternator...it sux.

[1987cp]

If the lights are pulsating, there's got to be something wrong somewhere in the charging circuit. If it's the internal voltage regulator, that'll go away when installing a new alternator. If only I had time to jaunt out there (family visit complications ....), I've got a spare you can toss on to see. However, I think AutoZone will pick up on it being bad if you take the alternator in for testing while the car's getting the new motor put in. If the alternator/regulator unit tests good, it's time to start looking for excessive resistance in the wiring - specifically, the two big black wires and the small yellow wire should show very little resistance to the positive battery cable. A $15 digital multimeter from Wally Mart should be sufficient for testing needs, or maybe your unc has a nice Fluke multimeter you can borrow.

Hope this helps!

[Mr. Land Yacht]

I'll have my uncle check it out...see what he can come up with.

[gadget73]

its pretty common. clean the engine to body grounds, but don't expect much. Its the voltage regulator kicking in and out, or you've got a bad diode bridge in the alternator. I fixed this on mine after the stock alternator caught fire. No pulse with the 3g, though I'm on my third one of those since mid '05.

[Mr. Land Yacht]

ok, thanx for the ideas mang!

[86VickyLX]

I've had this problem for a little while now...getting annoyed by it.

when I'm between like 600-1500 rpm, all of my lights pulse with the engine rpm...once it gets above 1500rpm, its pretty solid.
when it did this before, it was the fuse for my fog lamps...and that got disconnected when I replaced the red cable for the battery...just havent hooked it up yet.

is it maybe a bad regulator in the alternator or something?

it has done this on and off since I bought the car in Nov. 04...I have gone thru....2 alternators...I'm on my 3rd.
still has the same battery in it that it did when I bought it...an Interstate Battery.
I havent had any trouble with it...other than the corroded cable...and sometimes I've left my headlamps on and drained it..its happened a few times.

any ideas?
the only thing I'm thinking of is doing the "3G Conversion" that Bobert did to his old Merk...sure did keep the lights bright and smooth after that.

The only time my lights do that is when the car is in a gear other than Park or Neutral. Only at neutral. My battery has been drained several times lol. When my voltage regulator gave out, and when my alternator caught on fire. That's a reliable battery too. It's a Deka. I think I could've gotten a bigger battery for the car actually. it's smaller than it's battery box.

And on the subject of alternators. How do I tell what the amperage of my new alternator is? I don't see any things that say what it is. I got it out of an '86 Town Car, it's remanufatured, and a little bit bigger than my older one. But it fits right into the bracket, if that helps at all.

[86VickyLX]

However, I think AutoZone will pick up on it being bad if you take the alternator in for testing while the car's getting the new motor put in.

When I got my alternator from the junkyard, I took it to AutoZone for testing. They couldn't even get a reading. They said it was no good. I took the thing home, threw it in the car, and started her. She stayed running without being connected to the battery. It charged the battery too. So you can't always trust them. In my opinion, go to a few places to get an accurate reading. Like a second opinion from a doctor. Just a little warning.

[Mr. Land Yacht]

not a bad idea at all.
I got 2 auto parts places(Auto Zone/Advance) right next to each other...I could test it at both of them if need be.

[1987cp]

And on the subject of alternators. How do I tell what the amperage of my new alternator is? I don't see any things that say what it is. I got it out of an '86 Town Car, it's remanufatured, and a little bit bigger than my older one. But it fits right into the bracket, if that helps at all.

Just from my experience, the one I've seen that's physically larger is the 100-amp externally regulated version that went on police-package models. I was going to buy one for the '87 until I realized it was externally regulated, at which point I decided it was tons easier to stay stock with the 65-amp 2G. Seems to be working great with the homemade harness, too.

[gadget73]

She stayed running without being connected to the battery. It charged the battery too.

Bad idea to do that on an EFI car. The battery is required to keep voltage stable. You run a high risk of toasting the alternator and/or the electrical system by trying to run the car with no alternator.

[phayzer5]

the damage is worse with no battery...

[P72Ford]

When I got my alternator from the junkyard, I took it to AutoZone for testing. They couldn't even get a reading. They said it was no good. I took the thing home, threw it in the car, and started her. She stayed running without being connected to the battery. It charged the battery too. So you can't always trust them. In my opinion, go to a few places to get an accurate reading. Like a second opinion from a doctor. Just a little warning.

Look at the part number. Mine starts with 100A, hence 100 amps. Oops, I quoted the wrong post. Meant to quote how to tell amperage of the alt.

[P72Ford]

And on the subject of alternators. How do I tell what the amperage of my new alternator is? I don't see any things that say what it is. I got it out of an '86 Town Car, it's remanufatured, and a little bit bigger than my older one. But it fits right into the bracket, if that helps at all.

See above post. This is the one I meant to quote.