1987 corvette alternator won't hold charge
- Thread starter RStovall
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E
ecss
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If you turn the ignition On and the Battery icon in the DIC isn't On the Gages fuse is probably blown.
Open the passenger side door and the fuse is behind the fuse panel cover on the end of the dash.
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- #3
E
ecss
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Disregard the info about the gages fuse that's for a 89. :eyerole
I dont' have a 87 schematic but on a 86 it shows the Brown wire should have 12 volts on
it with the ignition switch On.
The 12 volts comes from a fusible link which is bolted to the battery jumper block/stud behind
and below the battery.
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E
ecss
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Does the engine start and run?
What AC do you have C68 or C60 and why do you say the AC has a problem?
What other items don't work?
Are you sure the Brown wire isn't broken at the alternator regulator plug?
You need to drop the driver side hush panel, turn the ignition On and verify there is 12 volts
on the Orange wire at the ignition switch connector. This wire goes to a splice and turns into a Brown
wire that feeds the 510 ohm resistor and then goes to the Brown wire at the Alternator regulator plug.
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- #10
E
ecss
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C60 is manual ac and has a sliding lever and rotary knob.
C68 is auto climate control and has push buttons and a digital readout display.
Where is this White wire on the back connector of the control panel?
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E
ecss
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I don't see on a 86 schematic a White wire going to the HVAC control head. There is a Pink/White?
Why did you apply 12 volts to the White wire?
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ecss
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Since I don't know what wire you applied power to I can't comment what that did to the control panel.
It appears at least on a 86 there is no battery indicator. On a 89 I know it's the bottom left bulb in the Driver Information Center and comes on when you turn the ignition On.
The 86 troubleshooting for no 12 volts with the ignition On for the Brown wire says if you have 12 volts on the Orange wire from the ignition switch and no 12 volts on the Brown wire, the 510 Ohm resistor is open.
No mention where that resistor is. Sometimes they use a piece of resistance wire and not a physical resistor.
Then they mention a 10 ohm resistance wire which could be a misprint.
If you put a resistor close to 510 ohms in series with 12 volts and connect the other end of the resistor
end to the Brown wire. See if the Alternator charges. Voltmeter should be 13 volts or higher.
Could be the AC problem is not related to the alternator problem.
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E
ecss
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E
ecss
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I'll post a schematic in a minute of the circuit for a 89 since you have the bulb.
I'm not sure what year they upgraded the alternator to a CS130 but here's the wiring diagram for a 89.
How many wires at your alternator plug and what are the colors of the wires?
To test the battery indicator bulb in the DIC you unplug the connector at the alternator.
Turn the ignition On and ground the Brown wire. The bulb should light assuming your 87 is
wired like a 89.
On a 89 the alternator plug has 3 wires.
Turn ignition On.
Small Red wire hot all the time. Sense wire.
Dark Blue wire hot with ignition On 12 volt comes from AC fuse.
With the alternator plug connected to the alternator the Brown wire will be grounded
by the alternator regulator and the battery indicator bulb should light.
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So the brown wire goes from the alternator to the regulator and thats what makes the bulbs in the cluster light up? If so alternator is new and checked out fine, where is the regulator? (sorry wiring in not my forte)
I know I have one small red, one small blue and one small brown wire.
I know I have one small red, one small blue and one small brown wire.
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