[jaycoburn]

Hello fellow members,
will try to be as concise as possible. Have a '66 Lemans with a newly rebuilt 400 out of a 67 GTO. Pretty much all components (alternator, starter, ect) are new or have been rebuilt. Also, the exhaust manifolds are the Ram Air sold by Ram Air Restoration. A metal heat shield was installed over starter before motor went back in.
Been driving car this past Summer & everything performs as it should with this exception : on the hottest days I noticed (2) things occurring. When I went to shut car off (say to get gas) & tried restarting I would get a ticking from starter for a few seconds before starter then turned over engine; additionally, I have noticed during those hotter periods my volt gauge only reading around 12.5 volts or less.
Took car for a drive yesterday in 35 degree weather & engine water temps stayed between 180 & 190 the whole time. Car would start without starter ticking when restarted & volt meter stayed at 13-14 volts while driving.
I think I know why my starter reacts the way it does when conditions get hot but I am more unclear about the alternator situation.
Will be in garage this weekend efforting to remedy these issues & was seeking some advice on how to address them.
Thanks !

[johnta1]

Does your alternator use the external regulator?
Did the voltage increase any with higher RPM's?

[george kujanski]

To add: a properly running alternator/regulator keeps the battery voltage at about 14.0 constantly regardless of electrical load. It may be slightly higher when the alt/reg is cold due to a built-in temperature compensation.

A hot engine/starter is more difficult to crank and requires that all electrical connections are solid. the clicking is probably from the starter solenoid..when it pulls in the Bendix drive, it pulls a bunch of current from the battery, and makes the connection to the starter motor. If the wiring/battery system is poor, the voltage at the starter solenoid drops, causing the solenoid to release, the cycle repeats.

A hot starter /solenoid makes the matter worse, since the wiring resistance increases with heat, reducing the available cranking current from the battery.

George

[jaycoburn]

Gentleman,
thank you for your replies. My alternator is a newer internal regulator one with very few miles on it. It's weird because upon start up (engine cold) my volt gauge shows that it's charging @ about 14 volts. As I drive the car & the engine reaches normal temps & I drive it around for awhile the volt gauge starts dipping between 12 & 13 volts. If I rev motor there is little if any noticeable change in gauge. Like I had mentioned I drove car for an extended period yesterday under very cool air temps (35 degrees) & at idle or under load my volt gauge read 14 at all times. I think the first thing I am going to do is just check all of my connections to make sure they are clean & tight (to battery, alternator, & starter).
As I mentioned, there are maybe 2 k miles on this motor & all ancillary componants are new.
After that if symptoms remain I will pull alternator to have it checked. As for the starter are there any ideas to protect solenoid from overheating & causing poor starts ? I do have an after market heat shield around starter now but it doesn't seem to be that effective.
Thanks !

[Bill Hanlon]

Let me guess: One wire alternator?

[Stuart]

I have a heat shield on the original rebuilt starter in my Bonneville and it's very close to the 425A exhaust manifolds; no problems at all when the engine is hot. Having said that, I know my one example doesn't necessarily apply to anyone else's situation.

The one thing I would say is make sure all your battery cable connections are clean and tight - both positive and negative, and at both ends.

[jaycoburn]

Bill, it's a 10 SI 63 amp 3 wire alternator.
I am wondering if I can't resolve the overheating solenoid issue if anyone has used a remote starter solenoid. I see that Mad Enterprises sales a kit for our applications.

[Bill Hanlon]

Originally Posted by jaycoburn

Bill, it's a 10 SI 63 amp 3 wire alternator.

probably doesn't have much to do with this problem, but where does the sense wire on the alternator connect to?

[george kujanski]

If the back of the alt is near a heat source, such as close to the headers/exhaust manifold, that may cause the internal regulator to lower it's regulated voltage, although on a 400 with OEM alt location, I wouldn't think that's an issue, unless the internal regulator is not correct for your application.

Per Bill's suggestion, check where the sense wire is connected ( the wire from the regulator plug #2 terminal).

George

[jaycoburn]

Bill/George, when I swapped to a 10SI alternator I purchased an alternator wiring kit from Mad Enterprises designed specifically for the SI alternators.
That said the wire connected to the #2 terminal @ back of alt is soldered to an existing red wire that came out of the original external voltage regulator (which is considered to be the #3 terminal, I believe).
Also, I double checked the path of the wiring coming out of alt & it doesn't appear to be adjacent to any heat sources. Except for the Ram Air exhaust manifolds & alternator swap the engine & compartment are period correct.
Thanks

[Bill Hanlon]

If I understand correctly, your #2 wire (the sense wire) is connected directly to the power wire coming out of the alternator. This effectively removes remote sensing, turning your 3 wire alternator into a 1 wire alternator with an added red "no charge" light on the dash. I don't know how much good it will do, but you might try connecting the #2 (sense) wire to somewhere that is electrically much farther from the alternator. My favorite place to connect it is to an electric choke on the carb if you have one. It is physically near, but electrically far from the alternator.

[jaycoburn]

Bill, let me try & clarify. As you know @ the back of the SI alternator you have a 1 & 2 terminal. It's my understanding that the #2 terminal is the voltage sensing terminal. So, the wire that I have connected to that #2 alternator terminal runs over to the original external regulator & is spliced into a wire (red) that goes to the #3 terminal (of the original external regulator). I read that the wire coming off of that #3 terminal is the voltage sensing wire of that regulator. Hope that helps & if so let me know if I have things wired correctly.
Thanks

[george kujanski]

Yep, that's where the sense point was on the original mechanical reg...the #3 terminal.Terminals from bottom to top: F, 2 (R term on 10DN alt), 3 (batt connection), and 4 (idiot lite).

george

[Peter Serio]

In the most simple terms here is a diagram of how an internally regulated 10-SI alternator should be wired.

If you want more information go to:


http://www.madelectrical.com/electri...esensing.shtml