89 crown vic charging system not working

[junkyardjeff]

Well not as its supposed to,the idiot light is not working and no power to the ignition side of the voltage regulator. If I put power to to it the charging system will work so where do i begin to find the source of the problem and this one has the heated windshield too.

[wayne petty]

Well not as its supposed to,the idiot light is not working and no power to the ignition side of the voltage regulator. If I put power to to it the charging system will work so where do i begin to find the source of the problem and this one has the heated windshield too.

yea.. but you have the factory service manual.. but do you have the electric trouble shooting section that is short and wide...11 inches tall.. 17 inches wide..  and only 3/8 inch thick???
looks like this.. http://www.faxonautoliterature.com/1989-Ford-Crown-Victoria-Mercury-Grand-Marquis-Electrical-Troubleshooting-Manual-P11458.aspx

how about a diagram i added some info on.. the lower half is for the heated windshield..



i don't have that section personally..

the heated windshield version is wired differently..  it has the heated windshield control module to control the alternator output and the relay that switches the alternator output to the windshield..

yes.. the relay shown on the left disconnects the alternator completely.. sends all the charging output to the windshield..    warning.. be sure that you have power on the alternator output stud.. if the big relay fails and leaves the output open.. .. you will smoke your alternator in a split second...

there are several wires and for  info not just for you but for other RRT members..

the ford voltage regulators have these connections..

I short for indicator..  this comes from the alternator lamp in the dashboard. the other side of the lamp is switched to positive when the key is turned on.. when the alternator is not charging the I terminal has LOWER voltage than is on the ignition switch side of the bulb.. so electrons flow thru and cause the bulb to come on...   when the alternator starts charging the voltage on I comes up and is equal to the voltage from the key. and the lamp goes out..

for everybody's info   a twist.. if you have a dim alternator lamp.. run my 6 part voltage drop test..  you have resistance someplace in the wiring or ground system.. causing the voltage coming from the ignition switch to be lower than the charging system is putting out..

waynes voltage drop test. http://i.imgur.com/WMDprhm.jpg

"A" stands for for armature.. actually a left over term from ford generators..  this depending on the system can have power directly from starter relay B+ side... or if you car does NOT use an indicator lamp but has a factory amp meter.. this A circuit will be switched ignition power.

STA or S, this is the STATOR output..  it is connected to the stator windings where the 3 or 4 windings wires are twisted together.. diodes are at the other end of each of these stator windings.  when the alternator is charging or has test power hooked to the FLD into the alternator.. this will have HALF the output voltage of the alternator.. if you have more than half.. you have blown diodes..  ford for many years used this STA output to also power the electric chokes..  this STA output is a AC signal for the voltage regulator.. it causes the contacts or transistors to make and break the FLD connection..  this changes how fast the field circuit is switched.. and prevents the massive issue of change in speed effecting alternator output.

FLD  or F.  the field circuit on ford alternators is for all accounts pulsed positive.  one brush inside the alternator is grounded to the rear case.. the other brush is hooked to the FLD terminal ..  the voltage regulator pulses positive power to this FLD circuit and the brush.. this changes the size of the rotating magnetic fields created in the ROTOR WINDING..  the larger the rotor magnetic field strength is..  the more lines of magnetic field pass thru the stator windings increasing the electron output.  now.. something that is NOT described.. the voltage regulators not only PULSE POSITIVE to the fld circuit.. but they pulse negative to it also.. this allows the voltage regulator to maintain an exact size on the spinning rotors magnetic field.  it pulses positive to increase the field size..but damps that with negative to reduce the magnetic field size..

WHAT IS NOT SHOWN... the voltage regulator MUST be properly grounded to the engine or the alternator case...  so the Negative side of the circuit is has equal voltage..  this ground voltage difference can also cause the alternator lamp to glow.. dimly or fairly brightly..

why do i post all this info... because if you know this.. all alternators work on this same theory..  the biggest difference is that most other brands power up the the brush that is usually grounded with positive power.. and the FLD circuit works backwards.. pulsing ground connection to the other brush.    this is an A circuit or a B circuit difference if you want to read up on it..

[junkyardjeff]

The battery light does not come on at all with the key on (all the other lights do) and the motor not running,I stuck a test light on the I terminal an the regulator and the light did not come on at all. I am going to pull the cluster and see if the bulb is burnt,I put 12 volts to the I terminal and it started charging and as soon as I disconnected it it quit charging.

[wayne petty]

its totally possible that the bulb is burned out..


can you find the windshield heater control module.. i don't know which of the 30 boxes my 89 CV service manual is in..

[junkyardjeff]

I do have factory manuals and done the test for a inop indicator and the bulb is good and getting power at both ends of the resistor on the cluster so according to the manual there is a open curcuit between the ignition switch and regulator.

[junkyardjeff]

Found the problem,when I was removing the heater core I tried to unplug this black box behind the glove box which turned out to be the heated windshield module and the indicator wire from the regulator went into it and it was not plugged in all the way. The indicator still does not work but its charging now.