Electrical Problem
 

After a no problem winter here is the symptomology

1. Ran fine and started right up after an hour drive.
2. Stopped at an Ace Hardware store and got no cranking when I went to start up.
3. Push started the car and according the the PFC commander the Alternator was putting out 14.1-14.5 all the way home.
4. At idle the alternator was putting out between 11.9 and 12.8 according to the PFC commander ( low output is due to underdrive pulleys)
5. Put a DVOM on the battery (relocated Optima red top) and showed 12.8 while idling.
6. Shut off the car and tested the battery with DVOM which showed 12.8 V.
7. Turned the key to the first on position (not crank) and the PFC Commander shows 9.0V.
8. Left the key on and disconnected all aftermarket power consumers (carPC, EGT amplifiers, sound system, AC inverter and TE Wide Band unit).
9. Commander still reads 9.0V.
10. Tested at battery with key on position, 12.8 V.
11. Tested connection at fuse block under hood with key on---9.0V
12. Tested connection at fuse block under hood with key off---12.8V.
13. Tested a keyed 12 V source with key off --- 0V.
14. Tested a keyed 12 v source with key on---9.0 V.


Suggestions are appreciated.

Seems to me that the battery is creating the proper 12v , and it's getting absorbed or dissipated somewhere between the battery and the fusebox. I'd venture a guess that there's something creating a lot of resistance between the battery and the main fuse, but it must be in parallel with the alternator since the problem is out of the loop when the car is running.



First thing would be check all the fuses, I'm hoping you've already done this.


Then, check the grounds and wires going from the battery to the main fusebox. It could be something as simple as a loose connection or corroded wire.



Good luck,
-s-

Thanks for the reply Scotty...

Problem remains that when the car is in the keyoff position there is no dissapation of voltage between the battery and the mains under the hood. I do have a Phoenix Gold 150A fuse in line between the battery and the mains and it is OK.

Only when the key is in the #1 on (Accessory) does the voltage drop to 9.0V. When the key goes to #2 position (crank starter) the voltage drops to 6.0V or below.

I guess I should check OHMs also with the car in the keyoff position, but I am betting that there will be no resistance since the Volts are identical.

I missed that part. In this case, it looks like something that is switched on when you turn the key is what's absorbing all the power. Looks like it's time to break out the wiring diagrams...

-s-

Have you had you battery tested, Mine was doing something like yours and it was just that my battery had over all "died"

I will have the battery tested in the a.m. In the mean time I am still hoping for suggestions.

Scotty--- I sadly realize that I am likely to become intimately familiar (once again) with the entire wiring diagram for the FD (Last time it was so that I could cut away large hunks of wiring I had no further use of since I went Single).

Wait a sec, Jeff... what's that? :confused:

The switch positions are like this: "OFF", "Acc" ,"On" and "Start"

Your "#2" is crank starter, so, is your "#1" really "accessory", or do you actually mean "On"?

Typically "On" will pull more current than "Acc" to power fans (and possibly screwed up winshield wipers & whatnot)... maybe a fuel-pump if you've custom-wired it. If this is the switch position that's causing the problem (ON), put your volt-meter across your ginormous 150A fuse and see if there's a voltage drop. If so, I'd second-guess that fuse.

Sometimes manufacturing defects in the fuse's construction & materials can pop up after being exposed to some vibration & heat. It look fine, and still have good "resistance" when you measure it using the miniscule current of the volt-meter; but under current load stuff like that can really bottleneck. Same deal with dirty battery connections (did you check that too? ;)) .

Good luck:bigthumb:

Insane--

Great post, thanks.

I did misname the keypositions. So the conditions experience in what I called the #1 position is actually the "ON" position and the #2 position is actually START.

Fuel pump is a drop-in upgrade so no custom wiring.
Battery connections are good, as are connections at the underhood fuse block.

List of things to do today

1. Have battery tested.
2. replace fuse with new one. (hadn't though about that)


Remembering that once the car is running the alternator is putting out 12.8 at idle (underdrive pulleys keep this value low) and 14.5 crusing down the road, the big questions still remaining are.

1. Can a screwed up starter motor cause this kind of problem?
2. Can a screwed up ignition keylock cause this kind of problem?

Battery tested OK and I even tried another battery
Fuse replaced

Still the same problem.

Keyoff----> 12.6 at battery and 12.5 at underhood fuseblock
ACC------> 11.9 at battery and 11.8 at fuseblock (car door open so lights are on and key-in alarm ringing.
ON--------> 12.0 at battery and 10.1 at fuseblock and PFC Commander
START----> unknown at battery but droping to below 6 according to PFC Commander

Still open to suggestions.

I've had a similar problem with a bad starter. As the starter was going out, the solenoid would stick and cause a drain on the battery.
Or you may have a short in the solenoid.

This also sounds like one of those pesky grounding problems so common with the FD.

good luck,
Tim

Jeff, is your battery actually draining?

If it's not draining...... check your starter, I remember how loud that sucker was.

Also, check the switch above your clutch peddle. Mine broke and wouldn't let the starter engage. If it's broke, just loop a jumper across the connector and that problem is fixed...

e

I'm sure you've check it but take a look at the main engine fuses, you know the little square ones that are a bitch to get out.

If you weren't familiar enough trying to sort out all my friggin gremlins??

Let me know if you need a hand.. be happy to help Jeff.

Justin

batt is not good. getting 12.8 v at the battery when ideling and 12.8 when off is a bad sign of the alt also

1.) The starter bypasses the (stock) fuses. If it were a stuck solenoid, you'd see the drooping voltage regardless of keyswitch position.

2.) I'd expect a screwed up switch to blow the fuses, if that were the problem by itself.

Of course, if both were screwed up, it'd be possible the ON position switch is shorted to ACC, triggering the starter which is too worn to actually turn, but still may draw significant current. :D Yeah... that's pretty far-fetched. ;)

Where is the Phoenix 150A fuse? Is it inline with the battery, between it and the starter? If so, examine the fuse block connections themselves

Here is the latest.

For all the "bad battery" advocates, I tested the battery twice, once at Auto Zone and again at O'Reilly's-----Battery is fine

"Bad ground" advocates, I hooked up one end of the DVOM set to 200 OHMs (not K Ohms) to the negative battery cable end (disconnected from the battery) and the other lead to the lock latch for the hatch (really not the best body ground)----less than .2 ohm resistance through the system----Ground is great

Rockon, JD and Insane----Thanks for the support guys.

Rockon and Insane Gideon----- The fuse situation is as follows

With fresh battery (12.8) and testing at the underhood fuse box end of the positive cable:

All Fuses connected
Key in the Off position----12.6
key in the ON position----10.6

Now with the key in the ON position
Pulling any fuse other than B1 or B2 (Both are Ignition fuses)----10.6
Pulling B2------11.7
Pulling B1-----12.1
Pulling both B1 and B2-----12.7
Replacing B2---no noticeable difference except drop from 12.7 to
Replacing B1---voltage drops to 10.6 and a noticeable clicking occurs from the AREA of the starter. I am not certain if it is the starter or starter solenoid.

Question: If it is the starter or starter solenoid clicking....is it supposed to click when power is supplied to the switch in the ON position, I thought it only was supposed to get power in the Start position.

Rockon--- I am still thinking that in the end I am going to have to pull the starter, but I am hoping I don't have to.

Finally
Insane Gideon--- The Phoenix 150 is in-line with the 12v+ cable and approximately 2 feet from the battery which puts about 4-5 feet from the 12v+ connection at the underhood fuse block. I am going to replace the fuse today and will report any changes.

Jeff,
Most likely it is the solenoid on the starter or the wires leading to the starter are coated with a residue of oil. See if the wires leading to the starter solenoid are covered with oil. That can cause an intermittant no start problem. It happened to me. I used to get an intermittant no start when the car was hot. I removed the harness, cleaned it, and rewrapped it and haven't had a problem since.
John

John

Thanks, I will check that this evening or tomorrow morning.

Jeff

Few things I see -

- Could be the ignition switch itself. There's physical contacts in the switch, and over time they get crud built up on the contacts and the voltage through the switch drops. Not an uncommon problem, really. There might be a test procedure for the switch in the shop manual.

- Could be the starter. Have you checked the voltage coming from the small power wire with the key in the "start" position? If it's substantially less than 12v, it's the starter signal wire, which comes from the ignition switch, through the security system and clutch switch, then to the starter. If it's 12v or so, it's something wrong with the starter. Most cities have starter/alternator repair shops that can do a diagnostic on the starter for you. It's REALLY simple to pull the starter off.

Dale

Ok, so the Phoenix fuse IS between the battery and starter then...

Screw Occam's razor, there might be two things going on here. ;)

Before you buy any new fuses/starters/etc.:

When I mentioned the "fuse" I meant the fuse, fuse-holder, and it's connections. Is it a crimp-on deal or is it soldered?

When you're seeing this voltage drop (ign. ON), put one end of the volt-meter on the battery's positive terminal, put the other end of the volt-meter on the Phoenix's fuse's "output" terminal that leads to the fusebox. Ideally, that should read near 0v (practically, say, less than a volt). If not, the fuse and/or it's terminal are becoming high-load-resistive which could choke off voltage from the starter (assuming the fuse is in-line with the starter).

As for the starter: If it malfunctioned by-itself and decided to start sucking current on it's own, you would ALWAYS see the voltage drop, regardless of key position... That is, unless I'm totally conFUSED (pun intended ;)) about where this aftermarket fuse is.

For a dying starter to be causing this, the key cylinder switch or maybe the associated wiring would have to be malfuncitoning as well, since the condition follows the switch. Who knows, maybe a winding short in the solenoid caused huge currents to weld the IG1-->Start contacts.

________

I'd take the phoenix fuse & its wiring out of the equation. Seeing as how your battery voltage doesn't even sag .1V (your first post), you're probably not even pulling enough current to blame on suspect accessories. This theory is of decent probability, and easy to check.

edit: Re-reading, it seems scotty's been saying this all along! ;)

Possible, if all else fails there IS a test procedure in the manual (BODY ELECTRIC MANUAL not FSM).


Actually it is a soldered system with the gold plated cable ends soldered to the cables and the gold plated fuse flats bolted to the cable ends by means of gold plated allen head bolts. The connections all live inside of a plastic case with screw on ends which have o-rings to keep the nasty humidity controlled inside.


OK these will be on my test list in the morning

I agree :) as to the starter but according to the Electrical Manual (Section Z) the Starter Cut relay (?) and the Starter Interlock Switch (Clutch pedal) are actually in the circuit and as Rockon said, if this turns out to be a screwed up clutch pedal switch or Starter cut relay (solenoid?) could we see a voltage drop and no starter spin...

This, or something like it is my guess of what actually is happening[/QUOTE]


Yup. and I haven't disregarded it as I have checked every fuse that is in the circuit....BUT I am willing to recheck again and again until I cure this problem.


I appreciate everyone's help and will keep you all posted on the developments in the am

Jeff, I've got no other suggestions on what is causing your problems........you're the man when it comes to that...

I do have one suggestion, though. You need to get it running because YOU ARE coming to the revolution. :)

I'm sure Jeff will figure it out.. Crazy 'ol fool has that damn car memorized.. :)

Emphasis on CRAZY and OLD :D


Rockon====> Somehow the powers that be seem to conspire to have my cars down just about Revolution time.

That starter cut relay is part of the security system. These things you mention can definitely prevent starting. They affect the start "signal" wire, but not necessarily the start "power" wire. But they shouldn't be dropping your voltage at the fusebox like that. Wow, ~3v is a lot. Did the car get hit by lightning lately? ;)