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Discussion Starter · #1 ·
Replaced my engine after a problem and almost a year later am ready to start it again, I’m going thru some tests and have encountered a strange issue, once I turn on the battery from the disconnect switch nothing comes on (normal), turn key on, all gauges etc start working, when I turn the ignition off the gauges which are on fuse/circuit 18 stay on and don’t turn off, if I pull the fuse and re insert it they don’t turn back on, before giving too much thought to it figured I’d post in case the ECU was doing something to tell that circuit to stay on. Pic of the motor almost ready to go...

05FFE72B-7CDB-4CFF-8A5D-49F49A419C21.jpeg
 

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Discussion Starter · #2 · (Edited)
The ECU also stays hot when the ignition is off, meaning it doesn’t go offline on the laptop, it does when I pull fuse 18, the amp draw is 9 with the ignition on, drops to 6 with the key off and .2 with the fuse pulled and reinstalled...

I think this has something to do with my new starter, I had an issue with the old one where a bolt where the wires terminate felt loose, I’m using the 94-95 starter and my solenoid is in the fender, I connected the wires the exact same, I didn’t install the initial starter or relocate the solenoid, I’m guessing I need to do something to the solenoid that’s on the 94-95 starter, I threw the old one away and can’t do a continuity check to see what’s going on, off to google I go...

it’s gotta have something to do with the ignition on triggering a relay to the new 94-95 solenoid and power traveling back to the factory solenoid in the fender, the 2 small studs on the new starter must have to be cut somehow to stop power flow, gonna pull the starter and check or I installed the small wire on the wrong stud, should be an easy fix
 

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1965 fastback 347 hci v3-si @10 psi Pro M efi. Tko600 3:55
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I’m too mesmerized by your engine pic to think clearly about what your asking 😂
Seriously, though that is really nice looking, and congratulations on almost being ready again.
I’ve got >5 weeks left before wisco is finished with my pistons and still plenty to do in meantime.

Sounds like you’re suspecting something with that starter circuit I’m not too familiar with the 94/95 starter and whether or not it has an onboard solenoid or not?
if it does then you shouldn’t really need any other remote mounted solonoid.
I’m sure by the time anyone reads this you’ll probably have it figured out by removing some of those suspicious wires
Now...Don’t be afraid to post more pics LOL !
 

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1965 fastback 347 hci v3-si @10 psi Pro M efi. Tko600 3:55
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Did you spray paint, anodize or have your Glenn’s fuel rails powder coated?
 

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Discussion Starter · #6 ·
I’m too mesmerized by your engine pic to think clearly about what your asking 😂
Seriously, though that is really nice looking, and congratulations on almost being ready again.
I’ve got >5 weeks left before wisco is finished with my pistons and still plenty to do in meantime.

Sounds like you’re suspecting something with that starter circuit I’m not too familiar with the 94/95 starter and whether or not it has an onboard solenoid or not?
if it does then you shouldn’t really need any other remote mounted solonoid.
I’m sure by the time anyone reads this you’ll probably have it figured out by removing some of those suspicious wires
Now...Don’t be afraid to post more pics LOL !
I’ll post some more once I have it dialed in, I’m pretty sure it’s something with the new starter solenoid, just gotta take it out and do a few checks, really nervous about getting it started, I always manage to screw something up
 

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Discussion Starter · #7 ·
Couldn’t determine anything that the new starter is causing any issue, the solenoid in the fender is always hot, regardless of the key position, my battery from the trunk connects to the starter, another cable piggy backs that goes to the solenoid in the fender and the 3rd is connected to the ECU, the smaller wire on the solenoid I believe runs to the opposite side of the hot at the solenoid in the fender, original post states what’s happening
 

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1965 fastback 347 hci v3-si @10 psi Pro M efi. Tko600 3:55
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the solenoid in the fender is always hot, regardless of the key position,
what do you mean by always hot?
How many terminals does the remote solenoid have?
and how many have battery positive with ignition off.

should only be one large terminal hot with Key off.


It should have one large post batt + then when small “start terminal” wire is hot during cranking the solonoid connects (internally) and gives the other large post batt + which goes to starter motor.

Some remote Solonoids have a ground terminal (will have two small terminals for the coil wires and the two large terminals)

others are internally grounded
(will only have one small post “start term”and the two large post )

Either way; only one of the large studs on remote solonoid should be hot all the time and the second one should only be hot during cranking position. Of course, neutral start switch or clutch switch can interrupt this
 

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Discussion Starter · #9 ·
Ok so it’s not the starter, has nothing to do with it or the solenoid, that all checked out ok... I started looking at the ignition and what happens in the on/off position on the column and what’s hot during on and off, ended up back at fuse 18 and tracing its source. With the fuse out I’m getting back feed and everything is still working it’s 1.3 volts less probably because the source is a small wire, it’s been about a year since I pulled the motor, I haven’t done any new wiring recently, I did add the boost control solenoids and think I pulled some pins at the harness and also prior to I added the supplemental harness, I’m just going to have to trace it out, not looking forward to it at all
 

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Discussion Starter · #10 ·
Did a little more testing and the ECU staying online with the key off led me to the ecm/sensor fuse in the passenger kick panel. So with that fuse removed the gauges function as normal and the key on and off etc.

With the fuse installed I believe it’s back feeding onto that fuse somehow, with the ignition on, both sides of the ecm/sensor fuse are hot, one at battery voltage and the other about 1 volt less, that wire goes into the pro-m harness and is labeled fuse 1, I’m guessing it goes back to the ECU, I haven’t removed the seat to check, I’ve contacted Chris with my findings.

My guess is I screwed something up on the supp harness or when I moved some pinned wires for the boost control because the boost control is throwing a DTC code, if I pinned a wire wrong maybe I’m energizing something that shouldn’t be, that’s my best guess, time to pull the seat and double check some stuff.
 

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Discussion Starter · #12 ·
keep at it. its always something dumb for me most of the time.

glad youre not blaming the system lol
Definitely wasn’t a problem before I pulled the motor a year ago, only wiring I did was move the wire @ the ECU for the boost control, I replaced the starter but that’s not the issue, I did splice an extension into my IAC valve, but that wouldn’t cause this, I’m really stumped on what it could be and how I’m going to chase it down, it’s gotta be something connected to a battery and ignition source at the same time, fun...
 

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how old is your ignition switch? pop the cover, disconnect the harness from the switch and check for power once again. get another switch and double check. buy from advance or autozone. they have a good return policy. just connect the harness to the new switch and manually actuate it. how
does the key feel when you start your car?

ignition switches aren't expensive.
 

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Discussion Starter · #14 ·
Figured it out, I have a turbosmart boost controller and I was in the middle of installing the pro-m stuff when my engine started giving me issues, I have a Y at my boost control solenoids, 1 to ecu, 1 to turbosmart, the turbosmart is backfeeding somehow thru the ECU, once isolated the ignition functions as normal, then I had a DTC code for the pro-m stuff, I never moved the wire behind the ECU, always something stupid... I’m ready to move forward now though and get this thing started...
 

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Figured it out, I have a turbosmart boost controller and I was in the middle of installing the pro-m stuff when my engine started giving me issues, I have a Y at my boost control solenoids, 1 to ecu, 1 to turbosmart, the turbosmart is backfeeding somehow thru the ECU, once isolated the ignition functions as normal, then I had a DTC code for the pro-m stuff, I never moved the wire behind the ECU, always something stupid... I’m ready to move forward now though and get this thing started...
This is also why its wise to run additional electronics like after market ecu’s, o2 controllers, cop power ect, off of relays so the circuits have galvanic isolation will not back feed into other devices.
 

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Discussion Starter · #17 ·
This is also why its wise to run additional electronics like after market ecu’s, o2 controllers, cop power ect, off of relays so the circuits have galvanic isolation will not back feed into other devices.
It may have something to do with me not moving the wire at the ECU, I’m going to try and move it later and see if the problem continues, I was in the middle of the install when I pulled the motor, either way I’m just glad I found it
 
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