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Delco Alt conversion

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sockeyedsushi

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I have it mounted and running but I am getting a 15 volt output. The voltage is now down to 14.8 at idle and never really falls below that with all the power on. Should it? I went to the recc three wire hookup, and it works. But? It appears there are two wiring diagrams for this install. One used the 3 wires and the 3 terminals on the Alt. The second conbines the large and small brown wires onto the screw terminal of the Alt and the brown/yellow tracer to the plug at # 1. Does anyone know the correct choice?
 
A "typical" charging voltage is 14.7 volts at the battery. You are not far from that number. Do you trust your meter?

Are you measuring the voltage at the battery or at the alternator? If you are measuring this at the battery AND you trust your meter, I would say your alternator is a bit overactive and you sould look into the situation.

I would look at the location and the quality of the attachment of the third wire. It is the sense wire and technically, should be attached directly to the battery so the regulator inside the alternator can best monitor the battery charging process. If the heavy brown charging lead is stout enough and short enough this isn't necessary. It all depends upon the situation, that is why there are two ways to do the hookup. An easy way to establish if the third wire must go to the battery or can be tied off short of the battery is to measure the voltage difference in the heavy brown charging lead between its connection at the alternator and the battery while the engine is running and charging. (You're right you're measuring a theoritical short circuit here) If the voltage drop in the wire is over 0.1 volts, the sense lead shold go directly to the battery.

Here is a link about alternator installation:
Understanding Alternators
 
WEll, I followed up on the testing of the alternator with the local re-build shop and all is running fine. The ouput is 14.8v which is within the normal range of off the shelf diodes. the wires are attched correctly and the new ammeter and voltmeter gauges work great. Good to monitor the new install. Tons of power and it runs a bit better. I am upgrading the lighting circuit with relays to save the dash switch, went to H4 headlights. Installed the new horns from a 1986 Cadillac Seville. They fit the stock mounts perfectly. Made in Italy they are. Hope to add fog lights and a CD player in the trunk next. Wait til the spring picnic. Wow, what a car.
 
many years ago i had my alternator tested at the local parts shop and was given a clean bill of health. the staff at the parts shop wouldn't believe me when i told them there machine didn't check all functions of the alternator and that their lifetime guarenteed alternator was bad. after spending a lot of money replacing various parts i finally replaced the alternater and proved that that was the original problem. ps. the parts store paid for all the other parts after a letter to the regional office, in part because of the names they called me in the store.
 
thanks for the follow up. I drove the car 600 miles last weekend and had no solid alternator problems. I found the harness I built for the original Lucas plug was arcing on the alternator mount and bolts. It even grounded out the dist/coil lead. Stopped dead on the highway in the middle of nowhere. little tape solve the starting problem. Later the arcing touched off the red alt light on the dash. I stopped and it was the harness again this time arcing nicely. I remounted it with a zip tie and ran 300 miles without incident. There is a thread on this site about valve adjustment. It tells the whole trip story. Thanks again. I will have it disassembled and updated immediately after I finish moving. bruce
 
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