Ground wire ohms
01-27-07, 12:33 PM
#1
Senior Member
Thread Starter
iTrader: (3)
Join Date: Jul 2004
Location: North Texas
Posts: 327
Likes: 0
Received 0 Likes
on
0 Posts
Ground wire ohms
Has anybody ever ohm tested the ecu wires you where about to beef up?
I did. On the smallest scale of my meter (200), I got .4 on 3a and 3g, or any combination of 2c,2r,3a or 3g. Pressure sensor to negitive battery terminal .6, variablr resistor .5, fuel pump test connector .5. With all these values less than 1 ohm its vitually non existint. That wont affect the electronics enough to justify cutting up the harness. The wire I purchased had .4 ohms brand new!
I did find 22.1 ohms on my tps groung wire to the negitave battery terminal. My car does hesitate when switching to secondary injectors. Does anybody think that's enough to cause problems?
I did. On the smallest scale of my meter (200), I got .4 on 3a and 3g, or any combination of 2c,2r,3a or 3g. Pressure sensor to negitive battery terminal .6, variablr resistor .5, fuel pump test connector .5. With all these values less than 1 ohm its vitually non existint. That wont affect the electronics enough to justify cutting up the harness. The wire I purchased had .4 ohms brand new!
I did find 22.1 ohms on my tps groung wire to the negitave battery terminal. My car does hesitate when switching to secondary injectors. Does anybody think that's enough to cause problems?
01-27-07, 03:55 PM
#2
Seduced by the DARK SIDE
Join Date: Apr 2001
Location: Orange Park FL (near Jax)
Posts: 7,323
Likes: 0
Received 2 Likes
on
2 Posts
Oh yes. That much resistance on your primary ground cable can drive the ECU nuts.
Also your high impedence meter may not show a weak connection that only gives trouble under load.
And when testing a circuit, jiggle the connector wires a little & watch for unsteady values.
Another variable: A circuit may have great continuity, but could be picking up inductive noise. For example, the CAS signal wires running next to the spark leads.
VOLTAGE TEST
Engine running, headlights & heater fan on high:
Alternator post to alternator frame = 14-14.5 volts (verifies the alternator output)
alternator post to battery (+) = 0 volts (verifies the primary + wire )
alternator frame to battery (-) = 0 volts (verifies the primary ground)
Turn off the motor, but leave the lights on.
Battery (+) to battery (-) = ~12.5 volts and holds steady. (verifies battery)
Also your high impedence meter may not show a weak connection that only gives trouble under load.
And when testing a circuit, jiggle the connector wires a little & watch for unsteady values.
Another variable: A circuit may have great continuity, but could be picking up inductive noise. For example, the CAS signal wires running next to the spark leads.
VOLTAGE TEST
Engine running, headlights & heater fan on high:
Alternator post to alternator frame = 14-14.5 volts (verifies the alternator output)
alternator post to battery (+) = 0 volts (verifies the primary + wire )
alternator frame to battery (-) = 0 volts (verifies the primary ground)
Turn off the motor, but leave the lights on.
Battery (+) to battery (-) = ~12.5 volts and holds steady. (verifies battery)
Thread
Thread Starter
Forum
Replies
Last Post
rgordon1979
3rd Generation Specific (1993-2002)
40
03-15-22 12:04 PM
alexdimen
3rd Generation Specific (1993-2002)
20
10-23-15 01:50 PM
