Delayed Charging / Alternator

[Chuckk1]

I recently replaced my alternator. I was given one by a friend so all I had to do was get a shop to install it. The very next day, I get in the car, start it, and notice the charge indicator (little battery symbol) saying that the battery is not being charged. Here I thought I'd saved about $300. I head back to the shop, hoping the battey alone will get me there. Five minutes into the trip, the charge light goes out and the voltage on the engine monitor goes back up to it's normal 14.9. I go to the shop anyway and explain. Of course, they tell me if I'd bought the alternator there it would be warrantied but since it wasn't, that will be another $180 to take it out and put another one in (the shop that I got it from did warranty it, but I'd have to bring back the first one. the mechanic tells me to just drive it for a day and see what happens. The rest of that day the car was fine. The next day, same thing. No charging until I've been driving about five minutes and the engine temp comes up over 200 degrees. A friend tells me that in some expensive cars there is a delay system built into the alternator, for whatever reason. The car has now been doing this for a week, same consistent behavior. Did the shop that put it in maybe fool with it to get me back & spend more money, or could there be such a thing with this alternator. Could this also be a computer re-set issue? SOmebody please help....

[Retro-D]

Originally Posted by Chuckk1

I recently replaced my alternator. I was given one by a friend so all I had to do was get a shop to install it. The very next day, I get in the car, start it, and notice the charge indicator (little battery symbol) saying that the battery is not being charged. Here I thought I'd saved about $300. I head back to the shop, hoping the battey alone will get me there. Five minutes into the trip, the charge light goes out and the voltage on the engine monitor goes back up to it's normal 14.9. I go to the shop anyway and explain. Of course, they tell me if I'd bought the alternator there it would be warrantied but since it wasn't, that will be another $180 to take it out and put another one in (the shop that I got it from did warranty it, but I'd have to bring back the first one. the mechanic tells me to just drive it for a day and see what happens. The rest of that day the car was fine. The next day, same thing. No charging until I've been driving about five minutes and the engine temp comes up over 200 degrees. A friend tells me that in some expensive cars there is a delay system built into the alternator, for whatever reason. The car has now been doing this for a week, same consistent behavior. Did the shop that put it in maybe fool with it to get me back & spend more money, or could there be such a thing with this alternator. Could this also be a computer re-set issue? SOmebody please help....

The alternator is self contained with no external computer controls. If all the connections to the alternator have been verified tight then I suspect a thermal intermittent with the new alternator. Where did your friend obtain the alternator?

[Chuckk1]

The alternator came from a reputable wholesaler here in SOuth Florida called Auto Electric Supply. The thermal theory sounds quite sensible to me. I'm just trying to figure what component in the alternator itself would be temperature sensitive.....diodes? What else is in there?

[Retro-D]

Originally Posted by Chuckk1

The alternator came from a reputable wholesaler here in SOuth Florida called Auto Electric Supply. The thermal theory sounds quite sensible to me. I'm just trying to figure what component in the alternator itself would be temperature sensitive.....diodes? What else is in there?

If your handy with a multimeter you can still check a couple things external to the alternator. There is a fused control circuit that feeds the alternator that originates back near the battery. Pull up the back seat and look for the fuse back there called "Batt Ther" and check to see if it's cracked or swap it wth another 10 amp fuse. This fuse feeds a battery thermistor located very close to the battery & cable (positive). This circuit winds up feeding the alternator with approx 8 volts and should be checked before replacing the alternator (terminal L at the alternator). Also check "Batt" terminal (red wire) at the alternator, this should read betwwn 13-15 volts. All these test are being done while the vehicle is not charging before warm-up.

RD

[Chuckk1]

I checked all that out....most of it. Swapped the 10 amp "batt ther" fuse for a new one. Couldn't get to the alternator for a measurement (very tight in there, and I don't like getting my musician hands near spinning machinery!!). Charging is still delayed by about 5 minutes after cold start-up. What's odd is, the charge indicator light does not come on immediately after start-up (cold), but about 10 - 15 seconds after. Indicated batery voltage on monitor panel is 12.1 - 12.3 volts until charging begins. Then it's up to 14.7 - 15.1 volts indicated. Thanks anyway, RD. You seem to be pretty knowledgeable on the Aurora. What's your spin on this chronic stalling business?

[Retro-D]

Well, if it turns out to be an internal intermittent problem with the alternator let us know. As for the many stalling threads I practice some degree of preventive maintenance with my 95 Aurora and have not had the stalling others seem to suffer. Here's my simple regime:
1, Don’t believe the owners manual, change your plugs and wires well before the 100,000 mile recommendation with OEM parts, use the exact factory routing for the wires.
2, Keep your EGR valve and passages clean, also use a spray throttle body cleaner on both sides of the throttle plate and keep the throttle body clean inside.
3, Replace the fuel filter regularly and use a fuel system cleaner once every couple months.
4, Try not to let anyone but yourself wrench on your car and also avoid the grease monkey oil change type places.
5, Use this board and others for information. I have learned a lot by the experiences of others shared here.

Good Luck

RD