[DUKEOFBLUZ]

I just had my alternator rebuilt and now my 2000 GMC Yukon 5.3 V8, will not idle .
It will run with my foot on the gas but it dies when I let off.

Any ideas what I did wrong?

THanks Duke

 

[docvette]

Doc here, imp:

FIRST, Be sure the battery is FULL charge, and in good condition, or the load from the engine controls will rob the Ignition of current, and die at low RPM's..

Try disconnecting the Alternator and try to duplicate the problem..If you can't, and it turns free by hand without power, you have a MAJOR draw (like a short) Posing a load on the alternator , rotor locking it.

In that case you will have to troubleshoot the charging system harness.

Doc imp:

 

[lowstreet]

Check the battery, My dodge truck just did the same as yours and it was the battery.

 

[DUKEOFBLUZ]

Thanks guys, this happened right after I installed a new alternator.

Then I was informed that this happens sometimes when the battery is disconnected. After starting a few times the truck "re-learned" what the idle should be, now its running fine.

THanks again, Duke