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Turbo Power Lights

If you have questions about anything listed, please use the MESSAGE BOARD. Information sources listed at bottom. This procedure was written for the 1980 through 1983 units which use a single switch. The 1978-'79 set up should be similar. NOTE: 1984-87 Turbo Buicks with the digital dash also use the same, single switch.

Turbo Power Lights Diagnosis

The Turbo Power lights on the instrument panel are a very simple boost gauge. The yellow and orange lights (green is not a light) turn on at about 3 and 6 psi respectively. They are controlled by a simple switch located on the driver's side inner fender or firewall. The switch can be adjusted by tuning the screws on the underside. This can be helpful for triggering devices like nitrous oxide or water injection at specific psi. A vacuum/pressure tube is connected to the turbo compressor along with the wastegate actuator and MAP sensor (if equipped).

To test the lights, simply remove the electrical connector from the switch. Insert a wire or paperclip and touch it to a ground. Once the switch is grounded, either of the lights should turn on. Test the other by grounding the other lead in the connector. If they don't light, first replace the bulbs. Remove the instrument bezel (pull outward), unscrew the lens and pull the gauge faceplate out. Sometime the bulbs are okay, but just need to be re-seated. If they still don't light check the fuses and the circuits for continuity.

Once the lights are working properly, reconnect the the switch. If you can, apply pressure to the switch with a hand pump. If they still don't light, the switch is bad (try re-seating it before replacing). Now test drive the car. If they again don't light, the switch may be bad (if the hand pump was not used), or the switch isn't seeing boost. Check the vacuum/pressure tubing, the MAP sensor, and the actuator for leaks. The only other problem could a bad turbo, but the complete lack of power would be very noticeable.

The Turbo Power gauge is not very reliable or accurate. I suggest installing an aftermarket boost gauge. Look for 0-15 psi or 0-20 psi scaling. There are some models with vacuum and pressure together. Go back to the "Turbo Notes" for more information about boost gauges.

Written by:
Rich George,
BEFORE BLACK Website

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