Host of electrical problems(Battery&Ignition)

[94GTStang]

To start off, my 94GT has about 113K on the clock and has a few mods. Recently, the alternator was replaced because the old one crapped out again. The red top Optima was also reading low so it was replaced with a new one just two days ago.
Coming home tonight, I take the U shaped entrance ramp onto the highway and notice that my battery light has clicked on and the voltage gauge reads in the N of Normal. I looked and everything looks just fine and the cables are on there tightly. I restart it and the light is still on and the voltage gauge reads the same. Try unhooking the battery and still the same.
Any hints?

Now, next problem...
Some time ago, the car stopped starting by just turning the key. Everything comes on when in the "on" position, but when you go to start it, it just does nothing.
The ignition module under the steering column was replaced and so was the tumbler (I know it won't do the trick, but hey it was cheap). What could be causing this to happen? Currently we have a sweet push button mounted on a plate in the ashtray to start the car. I would like to get rid of that though.

Any help would be greatly appreciated! I am on the verge of craziness with this car!

 

[HISSIN50]

I'd put a meter on the switch and sense wires at the alt to make sure they're seeing ~battery voltage.

The ignition switch sends 12 volts through the battery light and to the alt's regulator. WHen the alternator is not excited, that wire sees a ground path in the regulator. The battery light turns on. When the alternator excites, the regulator removes the ground and the battery light goes-out.

I'd check the gear position sensor for the starting issue (in the old days it was called a neutral safety switch). I think it's called an MLPS on the AODE's.

Good luck.

 

[94GTStang]

I believe the MLPS was changed with the Art Carr was put in. Of course, it wouldn't suprise me if that somehow got fried or I need a new one.

Now with the alt, I should use the multi tool on these wires? View attachment 440647 The small grey one looks a little funky (bent a little). Could that be doing something? The wire that gets bolted on and the large connector seem to be fine though. This alt. should be good still since it's less than a month old. Maybe 3 weeks

Thanks for your help! I will be tackling this tomorrow morning!

I've got the Chilton out and I'm looking at the MPLS and it says I need a special tool. That something I could get locally?

 

[HISSIN50]

At the regulator plug are 3 letters: A,S,I.

I = the switch wiring (that runs through the idiot light).

S = stator wire. It gets the alt the message to charge.

A = the sense wire. It monitors alt output vs battery voltage.

This diagram kinda gives an idea of the pathways.

I had saved a pretty good MLPS thread awhile back. It might help.

Good luck.

 

[94GTStang]

Thanks for the MLPS link! I will call around tomorrow and see who has it. I'm sure NAPA will carry one.

As for the alt, I will take the multimeter and check the voltage on those. Hopefully they will come back alright. I put the meter on my battery tonight with it running and it only cranked out around 12. Of course, before this mishap, the gauge was reading just fine/little above middle. Maybe when this alt. problem gets fixed, I won't be having this problem.

Thanks again! I'll be sure to update tomorrow

 

[94GTStang]

Double post

 

[94GTStang]

Well checked the alt and it didn't read anything. So I went ahead and exchanged that one again... I think that makes 7 alts for that car in 6 years.

As for the MLPS, the local oreilly's will have one for me at 5:30. Hopefully that fixs my starting issue!

I'll keep the updates goin!

 

[94GTStang]

Well.... FINALLY got a MLPS sensor from Twilight Zone and installed that. So now I am a proud owner of a sensor that didn't fix my problem Well, least I have a part that I don't have to worry about.

I'm now thinking it must be a ignition relay? I'll have to check out the Chilton's to find it.

 

[94GTStang]

I just came in from doing looking at the relays and still nothing. Now, my battery dies in a matter of 10 minutes or so and restarts if I jump it. When I pulled the big 40amp under the hood and put it back in, the turn signal and fog lights started flashing. Now when I open the door, that starts to happen.

I think this thing is a can of worms. I'm just going to take it to an electrical shop a buddy of mine has. If not, it's up for sale.

 

[HISSIN50]

I just came in from doing looking at the relays and still nothing. Now, my battery dies in a matter of 10 minutes or so and restarts if I jump it. When I pulled the big 40amp under the hood and put it back in, the turn signal and fog lights started flashing. Now when I open the door, that starts to happen.

I think this thing is a can of worms. I'm just going to take it to an electrical shop a buddy of mine has. If not, it's up for sale.

I'd consider taking the alt to the parts store for repeated bench testing (to heat it up a bit). It would not be the first time a parts store POS bit someone in the arsh (I have stories myself - several bad ones RIGHT-OFF the shelf!).

With the starting issue, how is your push-button doo-hickey installed? Does it jump the connections at the starter solenoid, does it grab the S-terminal from inside the cockpit? Basically, it sounds like you might be able to narrow down the issue by examining what's in the run of wire that's bypassed with your home-made switch.

Do you have an alarm system? The parking lights and fog light flashing sounds like an alarm-related issue.

Good luck.

 

[fordtech28]

The push button start is your number one problem it is contributing big time to all your other problems this is from experience I had a friend that had the same issue in his honda accord the not starting with the key so we put in a button like you did.Ever since then nothing but problems charging ,ignition so we spend about a day and a half going over all the wiring for the ignition and replace the wires that made the car start with the key what happens over time is that the wire that makes the car start gets lots of resistance equaling a no start situation I would have a buddy help you out to test all the ignition related wires from your dash going to the front of the car.Also I forgot to mention look at all the fuselinks and fuses it might be as easy as that one of the fuses shares the alternator and starter circuts its one of the big fuses under the hood and a small one as well the one that makes sends the alternator the signal to charge and that the car is on though charging the battery .
Good Luck

 

[94GTStang]

Thanks for the added help.

I might take the alt back in, but when the car is fired up, everything reads out normally.

The push button was put in because of the earlier mentioned problem with the car not starting at all. We put in a new starter and that didn't fix it either. I believe (it's been about 3 years) there is a wire running from the battery to the starter and one that runs into the cabin hooked up to the button.
Is there a diagram that shows me which contacts are what for the ignition switch under the dash? My Chilton's doesn't seem to have any that I could find.

I also checked all the under dash and under hood fuses as well. Those all seem to check out just fine.

I will get started on tearing down the push button starter and check out the wires for the ignition.

 

[WhiteDevil]

There is a fusable link between the battery and the alt i believe you might want to look at that.

 

[94GTStang]

There is a fusable link between the battery and the alt i believe you might want to look at that.

Do you know exactly where? Would it be at the end of that harness that was posted in the first pic of the alt?

When I get home, I'm going to look at the starter area and try to track someting down

 

[HISSIN50]

FordTech, it sounds like 94GTStang's push button starter wiring is done in parallel to the OEM wiring. That should not be an issue.
If a push button start is added in series or parts of the OEM ignition are bypassed, that's when issues can arise. The S-terminal current is so low that any wiring extensions or poor connections can lead to a lack of current to energize a starter solenoid. And obviously any modifications to the ignition switch can create issues. But a starter switch in parallel should be just fine.

The fusible link for the alternator that John mentioned is just to the driver side of the PS pump (between the PDC and the pump). I think that cable is kind of a piece of crap and replaced it with 4 AWG cable and a fuse.

Good luck.

 

[94GTStang]

Cool. I'll go check out that fusible link in a minute.
I just checked out the starter area and everything looks fine. The + cable to the starter is reading what the battery is putting out. I probed all the wires in the ignition control switch under the column and they all read out just fine. The ones that are activated when the key is turned all the way forward are working as well.

 

[WhiteDevil]

The fusible link for the alternator that John mentioned is just to the driver side of the PS pump (between the PDC and the pump). I think that cable is kind of a piece of crap and replaced it with 4 AWG cable and a fuse.

Good luck.

Exactly

 

[94GTStang]

Not to sound like a retard, but what should I be looking for? Everything is in those black shrouds, but there is a connector that connects all the alternator cables. Surely that can't be it.

 

[HISSIN50]

Not to sound like a retard, but what should I be looking for? Everything is in those black shrouds, but there is a connector that connects all the alternator cables. Surely that can't be it.

Not retarded at all. As I recall, if you look at the PDC and trace towards the PS pump, there's only one cable/black wire loom that goes towards the PS pump and alternator.

Alternatively, look at your ignition coil. The stock cable runs under it. Trace the sheathing from the coil to the side of the PS pump. The fusible link on my (seemingly unmolested) OEM cable was just inside the end of the wire sheath on the side of the PS pump. I pulled the loom toward the alternator a little and the link was right at the end and now visible.

Good luck.

 

[94GTStang]

Not retarded at all. As I recall, if you look at the PDC and trace towards the PS pump, there's only one cable/black wire loom that goes towards the PS pump and alternator.

Alternatively, look at your ignition coil. The stock cable runs under it. Trace the sheathing from the coil to the side of the PS pump. The fusible link on my (seemingly unmolested) OEM cable was just inside the end of the wire sheath on the side of the PS pump. I pulled the loom toward the alternator a little and the link was right at the end and now visible.

Good luck.

Cool. I knew there was only one wire that goes to the alternator, but I didn't happen to see anything obvious. I will take out all the plastic sheathing and take a look at all the wires.
Our cable is molested for we moved stuff a long time ago to make things look less clutered. I am sure I will find it now that I read your post.
I work all day tomorrow, but will look at it Sunday. I just can't think of anything else that could go wrong. Apparently this link will cause all my problems I'm having.

Once again thanks for your help! I will update as I go along!