Only 3 volts to injectors and coils. . .
#1
Only 3 volts to injectors and coils. . .
So I swapped my alternator to a fd alternator and it wouldnt start. I found I had no spark and I tested for voltage and im only getting 3 volts to my coils and injectors. I swapped my alternator back to my s4 one and same issue. Im guessing I shorted something but all of my fuses are intact. I have 12 volts going into the ecu from the black and yellow wire but only 3 volts coming out in the pins for the injectors and coils. The car is a s4na with a s4 t2 swap. Na chassis harness with t2 engine harness. Any thoughts?
#3
Moderator
iTrader: (1)
So I swapped my alternator to a fd alternator and it wouldnt start. I found I had no spark and I tested for voltage and im only getting 3 volts to my coils and injectors. I swapped my alternator back to my s4 one and same issue. Im guessing I shorted something but all of my fuses are intact. I have 12 volts going into the ecu from the black and yellow wire but only 3 volts coming out in the pins for the injectors and coils. The car is a s4na with a s4 t2 swap. Na chassis harness with t2 engine harness. Any thoughts?
The ECU is powered by the B/W wire from the Main relay.
The Main relay should have battery voltage on the "two wire" relay plug w/key to on.
#5
and i tested for voltage on the wire after the egi fuse, and im getting 12volts.
its weird because on the main relay, i tested for voltage on the four wire plug, and im only getting 3 volts.
and im measuring 3 volts at both the coil plugs, and the ecu pins. does anybody know the routing for power for these? like battery-main relay-ecu-coils and injectors?
#6
Retired Moderator, RIP
iTrader: (142)
Join Date: Sep 2005
Location: Smiths Falls.(near Ottawa!.Mapquest IT!)
Posts: 25,581
Likes: 0
Received 131 Likes
on
114 Posts
did you install the Fd alt correctly on the Fc Harness?
..when you install the Connector for the FD harness,One wire on the connector is to get 12 volts.( I put that one directly to the Big Black wire on the Nut).The other goes to the Dash gauge via the harness.
So One wire that was originally hooked up to the OLD s4 connector is now NOT hooked up,is taped and tucked aside.The other is hooked up to harness and supplies dash gauge.
you can just barely see it in my Pic.where one of the Pigtail connector wires is hooked up under the Big Black wire(12 volts) under the nut on top.That gives it 12 volts.
..when you install the Connector for the FD harness,One wire on the connector is to get 12 volts.( I put that one directly to the Big Black wire on the Nut).The other goes to the Dash gauge via the harness.
So One wire that was originally hooked up to the OLD s4 connector is now NOT hooked up,is taped and tucked aside.The other is hooked up to harness and supplies dash gauge.
you can just barely see it in my Pic.where one of the Pigtail connector wires is hooked up under the Big Black wire(12 volts) under the nut on top.That gives it 12 volts.
#7
Moderator
iTrader: (1)
so i should check for power on the b/w wire on that two wire plug?
and i tested for voltage on the wire after the egi fuse, and im getting 12volts.
its weird because on the main relay, i tested for voltage on the four wire plug, and im only getting 3 volts.
and im measuring 3 volts at both the coil plugs, and the ecu pins. does anybody know the routing for power for these? like battery-main relay-ecu-coils and injectors?
and i tested for voltage on the wire after the egi fuse, and im getting 12volts.
its weird because on the main relay, i tested for voltage on the four wire plug, and im only getting 3 volts.
and im measuring 3 volts at both the coil plugs, and the ecu pins. does anybody know the routing for power for these? like battery-main relay-ecu-coils and injectors?
The four wire plug at the main relay has 4 wires but 2 of these are constant power. The Black/Green wire and the White/Blue wire are the 2 wires which have constant voltage. The other 2 wires have voltage w/key to on. These 2 wires are Black/Yellow which you already tested at the coils, and the B/W wire (this is another B/W wire that is different than the B/W wire in the 2 wire plug).
Since B/Y has voltage then it should be a given that part of the relay works. When you find battery voltage on the B/W wire in the 4 wire relay plug w/key to on it will tell you if both aspects of the relay are working properly.
EDIT: If the B/Y wire has battery voltage w/key to on then it is a given that the B/W wire in the 2 wire plug has battery voltage w/key to on.
Trending Topics
#12
Moderator
iTrader: (1)
I stated already which wires in the 4 wire plug have constant voltage w/no key necessary and which 2 wires in the larger plug will have voltage "only" w/the key to "on." So White/Blue and Black/Green have voltage all of the time so no key is necessary but the relay passes the voltage from these 2 wires to the B/Y and B/W (same plug) only when the key is at "on" or better.
#14
Moderator
iTrader: (1)
The B/W wire in the 2 wire plug to the Main relay is supplied voltage from the 15 Amp Engine fuse found in the interior fuse box. The key being turned to on takes constant voltage off of the Black wire in the ignition switch and passes the voltage onto a B/W wire running from the ignition switch to the interior fuse box where the Engine fuse is. The Engine fuse then passes voltage onto the Main relay via a B/W wire.
Thread
Thread Starter
Forum
Replies
Last Post
HalifaxFD
Canadian Forum
126
05-09-16 07:06 PM