If both the alternator and the battery are good, either the alternator isn't turning fast enough (slipping belt or engine idle speed too slow), or you have a wiring problem.
To check your wiring, look for the "1" terminal on the back of the alternator (left side of spade terminal connector). When you turn the ignition key to the run position without starting the engine, the alternator warning light should be at full brightness. If the bulb is burned out, the alternator will not get the excitation current it needs to start up (it goes through the bulb). With the engine running, you should measure 12 Volts at the 1 terminal (this is the excitation terminal).
Another thing to check is whether the battery charge wire is good. If it is corroded inside at the battery clamp end or burned out, you won't get charging even though the alternator appears to be working. If you don't have an ohmmeter, you can make a quick test by adding a new 8 AWG wire between the output terminal and the battery clamp. If the battery now charges, the original wire is bad. If this works, I recommend installing an inline fuse at the alternator end no larger than the largest size used in your electrical system, just in case something happens to the jumper wire. That way you won't burn out your alternator.
The heater/AC issue could very likely be a separate problem, but inadequate power may keep that system from running properly. (Note: low idle speed or belt problems will also be detrimental to AC performance.)
ty but the battey cable is good u lost on jumping a wire from were do i jump the wire to dont understand what you talking about
and i have no atl light its a gauge only
and i have no atl light its a gauge only
and when i rev up the motor it does not a thing
motor idle is at 600 when hot 900 when cold
There is a wire from the alternator to the battery. Sometimes it goes from the alternator to a binding post which also has wires to the battery and the rest of the vehicle's electrical system. The alternator end of the wire has a ring terminal and is secured with a nut to a threaded insulated copper post on the back of the alternator. There is usually a rubber boot covering this post to protect it from moisture and short circuits.
There are two types of gauges - one is a voltmeter, and the other is bi-directional ammeter - the latter shows current in the charge or discharge direction, with the needle centered when everything is off. Which type do you have, and what is it reading?
The next thing is to verify that the voltmeter is telling the truth. Measure the voltage right at the battery terminals while the engine is running. If it is reading 13.6 volts (give or take a couple of tenths), the battery is charging and the dashboard gauge is off for some reason. If the battery reads close to 11.5, I'll need the voltages at the alternator terminals to figure out what's going on. Specifically, the output terminal should read the same as the battery, and the field terminal (the "1" terminal) should be close to the output voltage, although it may be slightly lower. Usually the plastic connector shell on the field terminal cable has an open pocket so you can slide the voltmeter probe inside to touch the contact while it is connected to the alternator.
ty now i have only 10 3 in the car took the car to the auto zone they said nottihng is comeing bout of the atl took a jump wire like u said and not a thing happen so now what
That implies the bulb is part of the dashboard voltmeter circuit and it's making it read low, or it has too little resistance and is messing up the voltage regulator operation. Maybe somebody put in the wrong replacement bulb there. It's the alternator warning light I mentioned earlier - it's supposed to alert you to charging problems before the battery voltage drops. Does the alternator start charging right away when you start the engine without the bulb installed?
Regarding the heat and air conditioning: do you get any air movement when you switch to Vent? Does changing the fan setting make any difference in air flow?
the air does not a thing no air no heat it is auto cam contro it does nothing at all it was the bulb fond that out my self but the i said i dont get any thing from the no haet no air nothing works at all the rear def the vheated mirrors can u help me out on this driveimg me nuts lol
yes it starts charging right away with the bulb out
I'm not familiar with the 1989 Corvette controls, but I know many GM vehicles from that period used an electronic pushbutton panel for the Heat/AC/Vent system. The buttons had LEDs inside small rectangular windows to show which function is selected. If this your controls are of this type, do you get lights in any of the buttons when you press them? What indications do you have that the controls are working?
Note: if your blower motor is not running, you should still get a slight breeze from the dashboard vents in Vent mode when you are driving at highway speed, especially if you have window open a bit.
yes i get them to light up when i trun on the lights but thats all i get when i puch the buttons not a thing hapens at all i lookdt the fuse is good 4 the air its a 25 map fuse am lost again lol can u haep me
The green LED indicators are separate from the dashboard illumination that comes on when you turn on the lights.
When the AC is off, the AC compressor pulley will turn, but the clutch next to it stays still. When it is on, the clutch is engaged and it spins also. If the AC indicator light comes on when you push the AC button, check to see if the AC compressor clutch is engaged. If it is, the controller is probably working and you have a bad blower motor or stuck blower door under the dashboard. If the AC clutch is not engaged, the controller unit is defective.
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Typo? Did you install a new alternator? If so, verify that all connections are secure - I've seen more than one person finger-tighten the nut on the battery charge terminal on the alternator and forget to snug it down afterwards. Test the battery also - it may have been excessively discharged too often while you had the old alternator and it can no longer take a charge.
It's also possible the new alternator is defective.
ty evar thing is snug they say the battey is good
one more the air dont work at all no heat look at the fuses all are good
just back from the auto srore the battey is good and the atl is good allso dont know what to do now lol
i have the read out type and it is saying 11.5
I DID WHAT U SAID ABOUT MAKEING A JUMP WIRE AND STILL NOT A THINK SO NOW WHAT
ty i think i found what was worng all it was was the bulb in the dash 4 the battey pull in out and volts went back up to 13.9 put the bulb back in went down to 11 .6 blew my mind it did that
hi ty i fex the no chargeing but still dont have no air no heat it dont do a thing not a think
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