Upgrading Alternator Wiring Question

[boomboom]

I am putting together a 75 spider project car from parts from three cars. We I tried to hook up the wires to the alternator and found the car had two wires (grey and yellow/red) and the alternator only take one of them.

After doing some research I realize I am putting a Bosh altenator with an internal regulator on a car that has an external regulator on the fender. What wires do I need to change to get this to work? I assume I plug in the yellow\red wire in to the alternator, but I don't know what to do with the wires on the external regulator.

The car has the usual black wires and a grey wire and a yellow/red wire at the alternator. The regulator on the fender has a grey wire and a large orange wire.

Thanks.

[mdrburchette]

I did this not too long ago on my '72.
I connected the yellow/red wire to the terminal and kept the grey wire disconnected. black power wires go on stud. At the regulator, disconnect yellow/red and violet/white at relay and connect them together. It should read a steady 13.5 v at the back of alternator and the light should go out when engine started. I had a problem with my light not going out until I revved the engine up to about 3k rpms. This was repaired by adding a diode to the yellow/red wire.
Hope this helps.

[boomboom]

Thanks for the info. Can you tell me more about th diode? What is it and where would I get one? Is there a certin type?

Thanks.

[mdrburchette]

I got one from Radio Shack. I'll see if there's any more info I can give you....just can't remember. The light not going out until it's revved that initial time is not a problem. Once it's revved a few rpms the alternator will start charging and the light stays out. It was just annoying to me.

[wmpwilson]

I just did this as described, and as soon as I hook up the Yellow/Red and Violet/White wires, I get a red light on the dash, with the key turned off. The car will start and run, and it appears to be charging (my volt-meter is freeking out just now, so need to get a new one), but am not sure what is up with thte dash light. I have been trying to figure out the electrical charts for my 1977 which I got from this site, but am having difficulty making it reconcile with what I have on my car.

Anyway, thoughts/suggestions are always appreciated!

[mdrburchette]

Does your model have a charge light relay? I can look at my setup to see how I wired it. I remember having to try several different things to get the conversion right.

[wmpwilson]

I'm not really sure of anything at this point. I haven't been able to get a definitive wiring diagram for a 1977 spider (it seems that there are a few years which are neglected). I am going to purchase a manual, then try and trace things down. I pulled the the two wires out of a relay mounted on the firewall near the external voltage regulator. Does anyone know of a supplier for the relay cluster mounted on the firewall? I hope I am using the right terminology!!! The relay pack is at the bottom of this photo----


Thanks!!!

[mdrburchette]

Try this link for a wiring diagram:
http://users.chartertn.net/jseabolt/elect.htm

[wmpwilson]

Thanks for the link. I had already downloaded the diagram for my 1977 Spider. It just really was not making much sense to me. Therefore, late last night I decided to download the diagram for a 1976 Spider! Bingo, it all started to make sense! I should have known something was up when trying to get parts at local parts store--like the alternator---they gave me one with an internal regulator, but I have an external regulator. I will put wiring back to the way it was before I did anything, then see if I can make the internal regulator alternator work right. Do I need to unhook the wiring from the external regulator, or leave it alone?

Thanks,

[wmpwilson]

Another question----I have the 14057 Alternator which is what the parts store said I needed---it has an internal regulator, but also two male pins for connecting wires---the yellow/red , and the grey. Is the connecting pin on the alternator just left unused, or is this the wrong type of alternator for my configuration?

When I combine the wires at the Battery Charge Relay, my charge light on the dash lights up, even with the Ignition in the off position. It seems that this should not be the case, but I can't see where the voltage is being supplied from--any thoughts? I still haven't been to parts store to get new Voltage/Amp meter, but the indicator lights on the dash panel get brighter as I rev the engine, which indicates to me that the alternator is producing amperage/Volts.

[mdrburchette]

I just looked at my setup although I can't remember if my alternator has one or two connectors. I have the yellow exciter wire connected and the grey one disconnected. I also have the external regulator and charge relay in place but I took the black wire and yellow wire from the relay and soldered these together. Now my regulator and relay are good for nothing but engine compartment ornaments.

[wmpwilson]

Thanks for you answers and help!! I have determined that my Charge Light Relay is bad. Right now, I have switched relays with the horn, so I am troubleshooting the wiring....I think the first order of business is to clean all my grounds, and determine if I have any unusual wiring "fixes" by the previous owner. I have owned this spider for over two years, but have never driven it more than around the block, so there are a lot of things I need to get familiar with......thankfully, it does start and seems to run adequately!!!! Does anyone know of a good source for relay's? I think I need to put in a whole new relay pack assembly.

Thanks again for help.......

[mdrburchette]

If you're changing the system over to a Bosch alternator with internal regulator you don't need the charge relay.
On the relay you have a black wire (goes to tach) and yellow wire (goes to alternator). When you connect these together you are bypassing the relay. The external regulator is bypassed when you know longer use the grey wire at the alternator. If the alternator light stays on, it could be a faulty bulb. If you need relays you should be able to get them at Vick's Auto or International Auto.

[wmpwilson]

I've been processing this in my head for quite some time now, and I am thinking that I have a bad diode in my alternator. Sitting with key off, battery hooked up to alternator, I am getting voltage coming off the yellow/red wire connection. The alternator is 2 years old, but the car has never been driven since I have installed it. It has been having problems from the first day I have installed it. I am going to try and return it to see what my options are.

Thanks for help....

[So Cal Mark]

a faulty bulb will not stay lit. An illuminated light without the key on means voltage is feeding back from the alternator to the bulb