Moparts
Just upgraded my alternator and my headlights blew out!
Posted By: Cudalord
Just upgraded my alternator and my headlights blew out! - 08/30/10 07:35 PM
1970 Cuda 440 orig non a/c car
OK, I just upgraded my alternator to a later style Nippondenso from a 1990 Dodge Truck (Picture attached).
It was a pretty simple install, and when I fired the car up, the lights were nice and bright, and the volt meter jumped up to 18V+ when I revved the motor a bit, then "pop", one of the headlights blew out. Well, I chalked it up as a bad bulb, and kept revving, then "pop", there goes the other lamp. I turned on the high-beams, and you guessed it, "pop" and now those are both out.
I didn't change the wiring at all, as I've been told this is a direct boltin/swap as far as the wiring goes. I did however run an additional heavy gauge wire from the alternator output to the starter relay stud.
What would have caused this? This is a 90 amp external regulated alternator. The reason for this swap was because I'm running an electric fan, A/C, and needed more juice, now I have too much!!
Posted By: 05dakota
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 07:37 PM
sounds like a no regulator issue?
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 07:42 PM
The regulator is there, and wired in. I traced the field wire on the back of the alternator to the voltage regulator. Like I said, I kept the wiring stock. The VR is fairly new, probably been on there for about a year.
Posted By: SNK-EYZ
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 07:53 PM
It sounds like a regulator issue.
Normally the charging system tops out at about 14.5 max, and that's on a discharged battery.
Very much above that and you start frying things.
18 volts is waaaay to much for the bulbs to handle.
Posted By: Andrewh
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 08:02 PM
regulator issue.
you didn't say why you thought it was a direct wiring swap, what regulator do you have? single field or dual field?
WHAT CAR IS IT, and how did you wire it in?
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 08:11 PM
1970 Cuda 440
All articles/archives I read on this swap stated it's a direct swap. Dual Field Regulator.
http://www.allpar.com/history/mopar/electrical.html
Posted By: Andrewh
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 08:59 PM
yep it is for that. sounds like it blew out or something happened to your wiring when you spliced in the new plug for the alt.
I would replace the vr or have it tested, and back track your splices.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 09:33 PM
Thanks! I actually have an extra VR on hand, and I will try that first after double checking the wiring.
I was thinking it was the wire I added from the alternator stud to the starter relay as it bypasses the VR... Would you guys recommend that I keep this wire there, or no need for it? I did add a fusible link to it.
Thanks again!
Posted By: Andrewh
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 10:11 PM
that doesn't by pass the vr. That is a feed line to charge the battery. will help keep the strain off your old wiring. I would leave it. And I would get rid of the fusible link.
Posted By: BigTerry
Re: Just upgraded my alternator and my headlights blew out! - 08/30/10 10:49 PM
on my exsuperbee I had similar problem I replace the vr alternator it didn't do any good finally had enough so I took it to my job mechanic he found a wire going into the bulk head into the dash was burn! he replace the wire had no more problem...
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 08/31/10 04:55 PM
Thanks everyone for the suggestions. I suspect it is a wiring issue, as the volts have always been a bit erratic even with the old alternator.
I'll be tackling it this weekend and will post the results, should this happen to anyone else.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/05/10 05:52 AM
Well, I've tried the obvious. I grounded the Voltage Regulator on to the block and cleaned up all the connections, Including the body ground. I even added a ground from the alternator body to the frame. Any other suggestions? The car fires right up and runs great, but when I rev the gas, it pegs out at 18 volts.
Let me just say this now, wiring is not my thing , so I may have missed something obvious... It's a 440 Cuda with Electronic Ignition, after-market A/C, autometer gauges (no ammeter). My voltage always fluctuated, but didn't become a problem before I put this late model alternator in it...
As always, I appreciate you guys. You always seem to get me out of a rut
Posted By: MoparMarq
Re: Just upgraded my alternator and my headlights blew out! - 09/05/10 06:42 AM
What BigTerry said makes sense. I would try the battery drain test to see if there's a miniscule short that's enough to drag the voltage down on the cabin side of the harness, but not enough to fry the fusible link or wiring to the bulkhead connector. I don't have my FSM handy, but I would disconnect the pos cable of the battery. Hook up a multi-meter that can handle at least a little current, between the the pos terminal of the battery and the cable. If it registers a current, there is a leak (or battery drain, if you prefer) somewhere. If the key is off, the leak would be somewhere between the battery and the ignition switch, as the reference voltage for the ignition (and VR) comes from the switch, IIRC.
Another way might be to simply disconnect VR with the iginition in "run", but the engine not running. See if you get battery voltage. If not, the column harness or dash harness may be the culprit. Work back with the voltmeter to see what's what.
I may be off-base here, so I hope others can chime in. Good luck with it.
-Marq
Posted By: MoparMarq
Re: Just upgraded my alternator and my headlights blew out! - 09/05/10 06:47 AM
After rereading my post, I realized that you didn't mention anything about the battery going dead overnight or over a week, so that's probably not the problem. The probelm probably lies somewhere between the ignition switch and the VR. I'd start tracing voltage back on the blue wire through the bulkhead to the ignition switch.
Sorry for the earlier red herring...
Posted By: Pool Fixer
Re: Just upgraded my alternator and my headlights blew out! - 09/05/10 01:27 PM
I'll add to that something that happened to me a few years back. the clip that holds my balast to the firewall (68 charger) didn't exactly fit the new ballast I had installed as part of my MP electronic ignition conversion kit. One day on a turn, it moved and the terminal on the ballast made contact with the metal clip...fried that wire all the way back to the engine compartment side of the bulkhead connector. I replaced it and tightened the clamp.
I was stupid not to check the wiring inside the car. years later while crawling under there for some other reason, I saw that the wire had actually fried itself on the passenger compartment side of the bulkhead connector. this thing was cooked!
the moral of the story is that you could have some fughazy wiring up under the dash and not even know it.
I did the denso alt swap a long time ago..2002. definitely keep the extra charge wire you added between the alt and starter relay. I used a 4 gauge wire, what did you use? mine is a 135 amp unit of an 02 ram van...even though yours is a 90amp, i'd still use a big wire. check your VR plug too. if it's the triangular shaped one, it could have some issue inside of it that you would never see.
Posted By: Pool Fixer
Re: Just upgraded my alternator and my headlights blew out! - 09/05/10 01:32 PM
Quote:
Well, I've tried the obvious. I grounded the Voltage Regulator on to the block and cleaned up all the connections, Including the body ground. I even added a ground from the alternator body to the frame. Any other suggestions? The car fires right up and runs great, but when I rev the gas, it pegs out at 18 volts.
Let me just say this now, wiring is not my thing , so I may have missed something obvious... It's a 440 Cuda with Electronic Ignition, after-market A/C, autometer gauges (no ammeter). My voltage always fluctuated, but didn't become a problem before I put this late model alternator in it...
As always, I appreciate you guys. You always seem to get me out of a rut
I see that you covered the bases on cleaning up connections and grounds, etc.. but did you try the extra VR you have on hand? maybe I missed something but I didn't see you write that you changed it.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/06/10 10:35 PM
This weekend I actually replaced the VR and Plug, and double checked the wiring. Not a single difference. I'm at a loss here...
Maybe it's time to take it in to have another pair of eyes look at it. I just hate to have other people touching my ride. Argh.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/08/10 06:02 AM
I took some time tonight to look into this again. After pulling off all the tape and wire looms, I traced each wire back to it's origin. After looking closely at one of the field wires, it was pinned between the alternator and head. I loosened the alternator, and there it was; bare wire was rubbing against the block.
I'm making progress, and now the volts are pretty steady, and max out at about 15.5 when I peg the gas. Should I be concerned? This still seems a bit high.
Thanks again everyone!
Posted By: 540challenger
Re: Just upgraded my alternator and my headlights blew out! - 09/08/10 12:39 PM
Quote:
I took some time tonight to look into this again. After pulling off all the tape and wire looms, I traced each wire back to it's origin. After looking closely at one of the field wires, it was pinned between the alternator and head. I loosened the alternator, and there it was; bare wire was rubbing against the block.
I'm making progress, and now the volts are pretty steady, and max out at about 15.5 when I peg the gas. Should I be concerned? This still seems a bit high.
Thanks again everyone!
15.5 is too high. What are you using to determine the voltage a gauge or muiltmeter???
also where is the 15.5 reading coming from the battery ir the alternator?
Posted By: RodStRace
Re: Just upgraded my alternator and my headlights blew out! - 09/08/10 04:46 PM
14.7V should be max, from what I've heard.
Sounds like you still have an issue with the sense lead to the VR.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/09/10 02:50 PM
The reading I'm getting is from the Auto Meter Gauge. It maxes out between the 14 and 16 line on the meter, closer to the 16. I have the ground on the voltmeter grounded to the motor, and the positive wire going to the ACC in the fuse box.
I'm going to be picking up a multimeter and running more tests on my outputs.
Posted By: 540challenger
Re: Just upgraded my alternator and my headlights blew out! - 09/09/10 03:35 PM
Quote:
The reading I'm getting is from the Auto Meter Gauge. It maxes out between the 14 and 16 line on the meter, closer to the 16. I have the ground on the voltmeter grounded to the motor, and the positive wire going to the ACC in the fuse box.
I'm going to be picking up a multimeter and running more tests on my outputs.
Good tyhe multimeter would be good to double check the gauge is getting the right reading. If the gauge is right your will have an even higher reading at the alternator stud 
Posted By: 451Mopar
Re: Just upgraded my alternator and my headlights blew out! - 09/09/10 09:57 PM
It sounds like the voltage regulator is sensing a lower voltage than the fuse block.
I would start by adding a ground wire from the regulator directly to the engine, them make sure you have good clean +12volt connections to the voltage regulator, and bulkhead connector.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/09/10 10:18 PM
That's one of the first things I did. I sanded the firewall down to bare metal and also roughed the back of the VR where it makes contact to the body. I ran a fairly thick wire from the mounting bolt of the VR to the block. Is that what you mean?
Last night I replaced the wires going from the field outputs on the alternator to the VR. I also added a secondary engine ground (from the head to the firewall) just to be safe.
I'll check on the voltage going to the bulkhead from the VR. Thanks for the suggestions, I'm getting there!
Posted By: hooziewhatsit
Re: Just upgraded my alternator and my headlights blew out! - 09/09/10 11:20 PM
When it's running, check the voltage going into the alternator on one of the two leads. I'm betting you'll find that it's about 1 volt lower than what you have at the battery.
This is the sum of voltage drops from going through the bulkhead twice, the ignition switch, and the ignition switch plug twice.
The voltage regulator is seeing a voltage that's ~1v too low, so it's compensating and giving you a 'real' voltage that's ~1v too high.
You can either clean all the connections and hope it helps (didn't for me), or you can install a relay that is turned on by the key, and switches a good 12v to the ignition system.
If you jump power from the battery to the voltage regulator, you should see the voltage at the battery immediately drop to ~14.5v.
Posted By: Pool Fixer
Re: Just upgraded my alternator and my headlights blew out! - 09/10/10 12:09 AM
maybe you could change the way that your system senses voltage. Here is an old drawing I dug up:
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/10/10 12:40 AM
I'll try your suggestions tonight. I got my multimeter in hand and I'm headed out to the garage (once the wife gets home, haha!).
Feel free to throw out your two cents while I'm working on it, like I've said earlier, wiring is my weak area so I may be missing something obvious.
Thanks again guys.
Posted By: hooziewhatsit
Re: Just upgraded my alternator and my headlights blew out! - 09/10/10 01:24 AM
Quote:
maybe you could change the way that your system senses voltage. Here is an old drawing I dug up:
Exactly! That's what I was talking about in my last post, in picture form.
If he checks the voltage at the ign terminal at the alternator, I'd wager it's ~1v lower than the battery.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/10/10 01:30 AM
So far everywhere I've tested the voltage, it has been at 14.45 max while the car is running, anywhere I test it. I suspect the voltmeter is off... Still working on it, just taking a breather.
Posted By: Cudalord
Re: Just upgraded my alternator and my headlights blew out! - 09/10/10 01:45 AM
I had a brainstorm, duh. I put the multimeter on the + and - of the voltmeter and started the car up. The multimeter read about 14.3 at average, and 14.4 max.
I think I'm in good shape. Just have a lot of wiring to clean up as I had to pull out the dash cluster and unravel all of my looms... Oh, and a voltmeter to replace
