Overheating alternator(again)

I am starting a thread on my delima of the overheating alternator. This is a 3G alternator, 200 amp. A little background first. The ignition system is the FAST XIM and XFI. These are basicly a plug and play distributorless system. No wiring is mis as they are all labeled and specific as to where they go. So I don’t think anything from this area is mis wired. This is a computer driven system and everything is picked up on the computer. When we first fired the engine up, they noticed that the program wasn’t recognizing the alternator. Everything ran smoothly for the time we ran the engine. All parameters were set and I took the car home. I noticed that the two banks of the exhaust were not even in temps. I also had a leak in a fuel line from the HP pump to its filter. To get to the line I had to remove the alternator. To my surprise it was not hooked up. The fuel line was repaired and the car was taken back to the shop. On hooking it up it was found to be overheating and frying the belt. It was also noticed that the pulley was becoming magnetized. A check with one of the auto electric shops led us to believe that the wiring for the alternator was amis. Took the alternator to the shop and it was converted to a one wire setup which required a new regulator. On checking its output, it was better than the original set up. The original was actually O K, just not as good. After hooking it up and adjusting the butterflys, the car seemed to run O K. We only ran if for a minute or two as it was 8 PM on a Friday. We didn’t hook the computer to it. Probably a mistake on our part. The car was returned home and run a time or two for break in. Occasionally getting the revs up but allowing it to run at an elevated RPM range of around 1200-2000 rpms. Temps were good on both sides this time. Temps got up to 180 and stabilized. It was here that I noticed my tank crossover system wasn’t working as I had hoped. As the tank was nearly empty, I shut it down and let it sit for a while as I needed to check out some other problems. There was an oil leak which I suspect is in a quick connect fitting.
I have the oil and gas lines on quick connects so that when the engine is pulled it is a simple matter to disconnect the lines without all the mess. The water line has a drain line that is used to bleed the system. The size of these lines made the cost beyond what I was willing to pay.
Back to the problem. I reconfigured the fuel overflow line so that for the time being it goes to the primary tank only. I am working on a new system for that. On firing the engine after all this, I worked the idle down to a reasonable range(under 1000 RPM). It was at this time I noticed the smoking and belt squal from the alternator. So I shut it down.
I have been thinking of possible things that would lead to this problem. The alternator is a 3G 200 amp unit from Ford, so I know it should be able to handle the load. Granted I do have a lot of electronics on this engine. Electrical wise I have running at the time, two fuel pumps 6-10 amps each, Spal dual radiator fans of about 13 amps each and an electrical water pump of 20 amps. I had about 9 relays taking care of all the duties. I was not well informed as to the power the relays used themselves. So to run all the coils in the relays I had two relays for just the coils. I have since learned that the coils use about an amp of power. In case you are counting I also have a Mocal trans pump and 7 ½” fan on a cooler which have not been turned on. There is an oil cooler fan as well, but it is controlled via a relay through the American Autowire 22 Highway series fuse box
The actions I have taken so far amount to eliminating the two relays to run the coils. A fused supply of 15 amp size will do for the remaining 7 coils and the low fuel lite(one amp signal). It cuts down on the number of wires coming out of the relay box. I am also replacing some other wires that in a quest to keep everything neat I pinched them and they have become shorted out. They were in the turn signals and weren’t being utilized as the rear hatch is off the car. I haven’t fired the car up since the last episode, but probably will tomorrow as I am off then just to see if I have done anything, which electricly is not much. So I expect I will have the same result. Randy has sent me some information, which may help. It is the wiring diagrams for the various alternators that Ford produces. Most include a 510 ohm resister on the optional instrument cluster charge lite circuit. Which of course is not utilized in my circuit. Randy stated that a 510 is near next to impossible to find and a 470 works fine. I am looking into what he has sent and how to check and/or adapt it to my system. I also will be seeking out some info about whether or not it is applicable to my system. So any of you electrical wizards out there, I would appreciate some hints or ideas.

Here is the diagram Randy sent.



Bill

Bill:
Just taking a shot here as I had a similar problem which turned out to be a bad ground. All of your power driven devices must eventually be returned to ground, and ultimately back to your battery. If you are consuming power or not the alternator will deliver power, based on the load it senses (Voltage drop). If you have a grounding issue the resistance can easily force the alternator output way up just to feed that bad connection, which gets hot and the resistance increases.
I may be wrong, but I would check the grounding of your alternator to the engine (Ususlly not an issue), your engine ground to the chassis, and battery ground to chassis/engine.
A one wire alternator is basically an entity in itself, it sees a low voltage and tries to increase it, and a high resistance connection can make it think more power is being used than actually is.
On your drive belt issue, if you have a 200 amp alternator charging at approx 14.5 volts you are producing approximately 2900 watts. One HP equals approx 749 watts, so your alternator is consuming almost 4 HP at full power, and with the small surface area of most alternator pulleys it would certainly cause slippage and overheating of the pulley.
A last thought, what size wire are you running from the alternator to the battery?

Hope some of this helps
Good luck
Phil

Hi Bill,

I must have misunderstood and did not realize that your alternator has been converted to a 1-wire unit. The external resistor is not needed for that alternator in the Excite circuit.

While grounds are VERY important particularly from the chassis to the engine block and alternator - I suspect that there is a problem with the alternator itself.

How have you got the charge wire from the alternator connected to the battery positive?

Bill I have to agree with Randy. I have a 200 amp one wire GM alternator, I also have an 55 GPM electric water pump, Electromotive TEC2 EFI, MSD DIS4 ignition amplifier that feed individual coils, two fuel pumps, one holley high volume low pressure, and a Bosch 044 high pressure, not to mention the electric water pump for the heater and two blower motors, AC compressor, and two high CFM fans, lights ect. No problem, I believe you must have a alternator problem or wiring problem with the one wire conversion. I like the GM one wire units, have them on both Ferrari's and my R5 turbo 2. They are simple and have the same type mounting as the ford.

Well,
I got all the wiring back together. I had lenghtened some of the wires to the relay box just so I could get to their connections without undoing several other pieces like the header tank and the swirl pot. On the advice of those here I inspected every ground connection and made sure thy made good contact with good metal. I noticed that under the dash, I had grounds coming from all directions, all 6 switches(most were linked),gauges, lites horn switch and extra power outlet etc. There were several lines that were then quick connected together and eventually to a common ground on the frame behind the dash. In an effort to make sure all connections were good, I then linked them solidly and soldered the connections. I also soldered a few positive connections on the gauges that I noticed weren't. With the negative lines I now had only one quick connect before it went to the frame.I left it because it made removal of the dash a little easier. After that I went to the starter and looked at its connections.I noticed the power wire that runs from the start relay was a little loose. Tightened it up. Then took the main battery feed, power to the alternator, and power to the fuse boxes which were on the same terminal of the starter off for inspection. The connection to the fuseboxes looked as though it was strained in that there was some copper wire showing as it made its exit and turned toward the front of the car. It was banded to the feed to the alternator.Removed the nut and inspected the wire. It was in tightly so all was put back on the starter. I altered the power wires to the two front fans from the relay box(fused only) to two spare outlets in the American box that were available. The terminal strips in the relay box could only handle up to 120 amps, and I noticed one of the connectors on the back of the box looked like it was starting to melt from too much power.
I started the engine and it ran a little rough at first but smoothed out. I adjusted the idle to 6-900 rpms and let it sit there keeping an eye on the alternator. The temps came up to around 160 on the water and later on the oil. the alternator stayed cool to the touch. So I think the problem was just a ground to one of the running appliances.
Next step is to get the clutch to functioning and it is on to the road!! Since I know nothing about the clutch or the Porsche trans, I will get some help with that. Right now the clutch doesn't want to disengage. I don't want to press to hard on the pedal. I am pressing pretty hard and it doesn't want to do its job. The mechanic that installed the trans had never done one before and didn't take real kindly to the Porsche guys recommendations or how they were given. So I will get the shop foreman out to have a look since he installed the slave cylinder.
I want to say thanks to all who contributed helpful ideas to get this devil of a problem solved. Without your help I would have had to spend a lot of time, energy, and probably cash to solve such a simple problem. I don't think I would have come up with it on my own.
Thanks again guys,

Bill