93 Dakota, Crank but no start
#131
05-09-2020 | 04:36 PM
Thread Starter
|
Record Breaker
Joined: Nov 2015
Posts: 2,016
Likes: 439
From: North Carolina
#132
05-09-2020 | 04:50 PM
Thread Starter
|
Record Breaker
Joined: Nov 2015
Posts: 2,016
Likes: 439
From: North Carolina
Heh. As it said on the tin, a 1993 
Checking my 1993 FSM, there's several good points to tap off a current switched 12V feed, besides the current field feed.
The 18ga Dark Blue wire to the alternator field is switched 12V now. Tap into that and leave it alone, and part of your job is done. (The OTHER wire, the 18ga dark green, is the one that you're actually cutting free from the ECU. It's at pin 20 of the ECU connector). That info is useful for connecting the FRM, also; it needs to go to switched 12V and to the dark green wire to the PCM. (Cut that one to split, and splice into the dark blue wire, and you'll actually have two of the three connections for the regulator; the third is the case to ground. It SHOULD ground with the mounting screw, but I'd add a wire to a nearby grounding point also because, well, I'm silly and paranoid about electrons not behaving ... )
The 14ga dark blue that runs to the evap canistor solenoid and the EGR solenoid is also switched by the ignition key (a quick read says that any 14ga to 18ga dark blue SHOULD be switched 12V, but I could be wrong on that. Eh. Stick with EGR/evap solenoids or AC compressor clutch 14ga dark blue or the run to the daylight running lights module for non-Canadian vehicles, also 14ga dark blue and you should be good.
The fuel pump was moved to a secondary relay with 1991; but its coil is also operated by the ECU, so the fuel pump is an acceptable "Only while running" tap for power (16ga dark green with black).
If using a relay, the coil can actually be paralleled with the current ASD/fuel pump relay coils (both driven off the same signals from the ECU); that's always a possibility. (Those are contacts A and C in the relay box for both relays, or the dark blue on one side and dark blue with yellow tracer on the other side). That avoids the field being energized and sucking the battery while just sitting there listening to the radio also; that's a good thing!
That 14ga dark blue wire also runs to the data link connector under the hood, and to the transmission overdrive solenoid connector. There's plenty of places to tap 12V switched under the hood, and all are currently protected by a fuse.
Or at least a fusible link.
RwP
Checking my 1993 FSM, there's several good points to tap off a current switched 12V feed, besides the current field feed.
The 18ga Dark Blue wire to the alternator field is switched 12V now. Tap into that and leave it alone, and part of your job is done. (The OTHER wire, the 18ga dark green, is the one that you're actually cutting free from the ECU. It's at pin 20 of the ECU connector). That info is useful for connecting the FRM, also; it needs to go to switched 12V and to the dark green wire to the PCM. (Cut that one to split, and splice into the dark blue wire, and you'll actually have two of the three connections for the regulator; the third is the case to ground. It SHOULD ground with the mounting screw, but I'd add a wire to a nearby grounding point also because, well, I'm silly and paranoid about electrons not behaving ... )
The 14ga dark blue that runs to the evap canistor solenoid and the EGR solenoid is also switched by the ignition key (a quick read says that any 14ga to 18ga dark blue SHOULD be switched 12V, but I could be wrong on that. Eh. Stick with EGR/evap solenoids or AC compressor clutch 14ga dark blue or the run to the daylight running lights module for non-Canadian vehicles, also 14ga dark blue and you should be good.
The fuel pump was moved to a secondary relay with 1991; but its coil is also operated by the ECU, so the fuel pump is an acceptable "Only while running" tap for power (16ga dark green with black).
If using a relay, the coil can actually be paralleled with the current ASD/fuel pump relay coils (both driven off the same signals from the ECU); that's always a possibility. (Those are contacts A and C in the relay box for both relays, or the dark blue on one side and dark blue with yellow tracer on the other side). That avoids the field being energized and sucking the battery while just sitting there listening to the radio also; that's a good thing!
That 14ga dark blue wire also runs to the data link connector under the hood, and to the transmission overdrive solenoid connector. There's plenty of places to tap 12V switched under the hood, and all are currently protected by a fuse.
Or at least a fusible link.
RwP
Shouldn't this regulator have it's own dedicated fuse?
#133
05-09-2020 | 05:48 PM
Champion
Joined: Jan 2013
Posts: 4,737
Likes: 372
From: Northwest Louisiana
It probably should, but as of 1993, it still didn't. It shared a fuse or fusible link with other circuits (being off the ASD feed or at least the ignition switch).
You still can piggyback there if you wish, but it's not switched, so the field can stay active the whole time the battery is in; that's one way to flat a battery overnight.
You really need a switched 12V feed to make sure.
RwP
You still can piggyback there if you wish, but it's not switched, so the field can stay active the whole time the battery is in; that's one way to flat a battery overnight.
You really need a switched 12V feed to make sure.
RwP
#134
05-10-2020 | 11:10 AM
Thread Starter
|
Record Breaker
Joined: Nov 2015
Posts: 2,016
Likes: 439
From: North Carolina
I will tap into a switched circuit for certain for the reason you raise.
You know, I'm wondering a bit about these Chrysler computers containing the voltage regulator. In all the time I've owned my truck (27 years) I cannot recall my battery ever measuring more than 12.3v. I think normally it should be 12.6v no?
The regulator in this kit I'm gonna buy is factory set at 14.3v. It's an adjustable regulator but I see no reason to change the factory setting. Agree?
You know, I'm wondering a bit about these Chrysler computers containing the voltage regulator. In all the time I've owned my truck (27 years) I cannot recall my battery ever measuring more than 12.3v. I think normally it should be 12.6v no?
The regulator in this kit I'm gonna buy is factory set at 14.3v. It's an adjustable regulator but I see no reason to change the factory setting. Agree?
#135
05-10-2020 | 11:23 AM
Administrator
Joined: Apr 2010
Posts: 82,774
Likes: 3,431
From: Clayton MI
#138
05-10-2020 | 12:46 PM
Thread Starter
|
Record Breaker
Joined: Nov 2015
Posts: 2,016
Likes: 439
From: North Carolina
I'm curious. My 1993 has the check engine flash reader. Can it read more than one code at a time? I ask in the event I can not turn off that check engine light from this regulator problem. Say, perhaps something else comes up that trips the light. Obviously I wont know when it happens but say I suspect an injector is going bad and want to check the flashes. Will it show both alerts and how would it sequence it? Anyone know?
#139
05-10-2020 | 12:54 PM
Administrator
Joined: Apr 2010
Posts: 82,774
Likes: 3,431
From: Clayton MI
The CEL will flash codes in order. Cycle the key three times, and it will start with the lowest code, and end with 55. Just gotta pay attention. Even the cheap code readers you buy for 20 bucks will read/display all stored codes. The more expensive fellers will do SRS, and ABS, and show history/pending codes as well.
The following users liked this post:
bronze (05-10-2020)
#140
05-10-2020 | 01:01 PM
Thread Starter
|
Record Breaker
Joined: Nov 2015
Posts: 2,016
Likes: 439
From: North Carolina
The CEL will flash codes in order. Cycle the key three times, and it will start with the lowest code, and end with 55. Just gotta pay attention. Even the cheap code readers you buy for 20 bucks will read/display all stored codes. The more expensive fellers will do SRS, and ABS, and show history/pending codes as well.