Auto Meter 4776 - Manual

INSTALLATION INSTRUCTIONS
ELECTRIC VACUUM &
BOOST/VAC GAUGES
®
2650-598A
12V BATTERY
VACUUM “T”
TUBING ADAPTER
NYLON
TUBING
MAP
SENSOR
+ 12v DASH
LIGHTING
GOOD ENGINE
GROUND
GOOD ENGINE
GROUND
FIREWALL
+ 12v CONNECTION
*SEE STEP 8 BELOW
RED
BLACK
WHITE
BLACK
Installation
1. Check that you have all parts required for installation, and the engine is cool.
2. Disconnect the negative (-) battery cable.
3. Gauge mounts in a 2
5 ⁄
8
” hole for 2 5 ⁄
8
” gauges, and a 2 1 ⁄
16
” hole for 2 1 ⁄
16
” gauges. Use supplied brackets and nuts to secure gauge to dash.
4. Drill 1” diameter hole where wires pass through sheet metal (such as firewall) and install rubber grommet provided.
(Grommet will require slit.)
5. Securely mount the MAP sensor to the firewall or inner fender with pressure port facing down. (Bracket fabrication may be required.)
6. Install T-Fitting in a manifold vacuum hose. Attach one end of the nylon tubing to the T-Fitting using a tubing adapter. Connect the other
end of the nylon tubing to the MAP sensor with the other tubing adapter.
7. Connect the white wire to dash lighting or switchable 12v light source, and connect the black wire to a good ground.
8. Connect the red power wire to a switched +12 volt source that maintains power during engine cranking. Most vehicles break the electrical
connection to accessories while the engine is being started. If the boost gauge is connected to one of these circuits, the auto zero
function will not work properly and inaccurate readings will result. To determine whether a switched source maintains power during
starting, look for electrical accessories in the vehicle that remain on while the engine is being started. Connect the red power wire to the
same circuit that powers one of these accessories. The connection can be tested by turning the key switch from off to on, the pointer will
move backward to the stop pin and then move to zero. Once the pointer has reached zero, start the engine. If the pointer reads vacuum
without returning to the stop pin, a suitable connection has been found. If the pointer moves to the stop pin and then reads vacuum,
another power circuit must be found.
Power-Up
The pointer will move backward to the stop pin and then move to the zero box. This procedure is an auto-calibration function and is
performed on every power-up. While this test is being performed, the gauge may make a clicking sound. This is normal.
Electronic Boost/Vac gauges are equipped with an auto zero function used to compensate for operation at varying altitudes. This function
takes a pressure reading during the time that the key switch “flies through” from the ON position to the START position. The reading
represents 0 pressure and is used to set the zero point on the gauge each time the engine is started.
CAUTION!
As a safety precaution, the +12V terminal of this product should be fused before connecting to the 12V ignition switch.
We recommend using a 1 Amp, 3AG fast-acting type cartridge fuse (Littlefuse® # 312 001 or an equivalent).
GROMMET
FUSE
(SEE CAUTION
BELOW)
PRESSURE
PORT
NOTE:
MAP Sensor should be mounted with PRESSURE PORT facing
down. Failure to do so could result in inaccurate readings due to
condensation in the line. (Bracket fabrication may be required.)
OPTIONAL
SLIT TUBING
RECOMMENDED
(AVAILABLE AT MOST
HARDWARE STORES)