goblues24

i dont know which challenge is bigger fixxing my problem or limiting this posts content. as my problem is an anomily(spell check) and i know how sensitive rx electricals are, i want to try to walk you through this as it happened to me by stating exactly what happened symptomaticcaly(spell check lol). ill start with the condition of my car , then give the recent changes that ive made to(what i believe) cause the problem.

my 89 vert. problem is not (99%) in logicon, i did a solid soldering job and had no probs for 4 or 5 months never a dim or funky lights coming on. the car runs great, no gremlins at all, except that my door keylight doesnt work, and never has since ive owned the car( the previous owner replaced the door so thats probly one of the reasons) my factory security doesnt work either nor has it ever since ive owned the car. when i open the doors all interior lights except the glove box work. no beeps ever (until what ill state later) if i leave the headlights on and exit the vehicle i get no beeps, when i put key in ignition i get no seatbelt beeps etc. ( i beleive i need to resolder the cpu next, havent done it yet) all other normal electonics work.

what i think is the problem that started the new gremlin which ill describe later, stems from the following actions. i was rebuilding my passenger side window regulator and went to test for proper cable function. this is where i made the only mistake. on my doors wiring harness i first hooked the regulator up to the connector for the regulator to the connector that plugs into the doors red and white interior lighting( the plugs match and i fucked up). i tried to operate the window while these plugs where improperly connected, from both the pass window switch and the drivers switch. ( oops)before i did this everything was a-ok!! i eventually connected properly and got the regulator to function.

after hours of reattaching to the correct plug many different times to test for correct operation of the cables i gave up and went to bed.

this afternoon i got into my car and drove to work. i began to notice oddities that happened chronologically in this order. i noticed that my clock was reset and that my interior lighting system no longer worked (havent checked any fuses yet, but dont believe fuses are the root of the problem)as i drove off i noticed that the car ran good but that my auto tranny brain had been reset because it shifted at way more aggressive points than my usual driving style( it shifted at way higher rpms) i then realized that if i turned my interior white light on,it didnt light up...the radio and clock turned off, if i turned the light back to the off position or the door actuated position, the radio and clock came back on with memory loss . also if i open the door,with the light in the door actuated position, the same happens( so the switch that operates the interior lightin is acuated it cancels out the radio and clock function, (the one for the door lights) after ten minutes of driving the idiot light's seatbelt warning comes on and i hear beeping(not since ive owned this car has that fuction ever worked ive never heard one beep, ever) it stayed on and beeped about 5 times then shut off. 3 or 4 minutes later this cycle repeated about 4 times in cycles. as long as i never opened the door or did any action that triggers the interior lights to come on, the clock and radio worked fine, but the radio presets were reset, no radio memory, each time the interior lighting was triggered the radio and clock reset with no memory.

i left work at about 3 am and turned the exterior lighting on and then the radio wouldnt work, the clock was off and a new idiot light stayed on indicating that a door was ajar. if while driving i turn the exterior lights off all normal radio and clock functions worked but were again reset indicating a loss of memory, and the door is ajar light went off. as i drove with the exterior lights on the idiot seatbelt warning never came on, i never heard any beeps, only the door is ajar warning was on. if i played with the drivers side door switch with the door open (at the base of the door which normally turns interior lights on) the idiot warning door is ajar light would dim a bit but never go off. if i played with the passenger side relay ther was no dimming. the only other not normal elecrical thing in my car that is not hooked up since idrove it this afternoon is the cig lighter, but i dont think this is the problem either.

all of this info leads me to beleive that i somehow crossed the electrical paths of the ecu, this is where i strongly beleive the problem will be fixed.

i guess my questions are...where exactly is the ecu i need to resolder? is it the one behind the passenger side kick panel? when i find and resolder this ecu(which was replaced before i owned the car by the previous owner about 1 1/2 years ago, per receipts) am i going to find that resoldering wont fix unless i replace certian diodes? and if this is the case are there certain specific diodes/relays that anyone knows exactly i should replace? or am i going to have irreversible damage leading to a complete replacement of the rx brain?

i feel the ecu is my problem anyone have any thoughts for or against this hypothesis? by experience of coarse. i want to say that i read a post a while back from a guy having these same symptoms, anyone know if there was resolution to his problem? please ask any of your electrical gurus to help me as i dont want to blindly go into this and cause more damage than my stupid plug accident.

please...anyone with this knowledge or anyone who knows someone whos gone through thes symptoms, and resolved....HELP ME

all input and advice/experience is welcome and hopefully this will help others as i know the people responsible for the electronics in these cars did a shitty soldering( the cold solder theory) before i go into the ecu id love some input.

thx in advance.

bauer

goblues24

a bump

Icemark

TOOO MUCH INFORMATION....

But, you have a blown room fuse and a CPU that needs resoldering or replacing. There are no diodes to replace, but the re-solder must be down correctly.

And I don't know what you think the Logicon has to do with any of it, the Logicon only controls the climate control. The ECU only controls the engine, so it will have nothing to do with your problems either.

You blew a fuse and have a bad CPU (that is found in the drivers kick panel).

Icemark

BTW, since you haven't searched and found your problem has been covered before I figure you may not have searched and found out how to resolder the CPU.

You need to remove the old solder first, then flow in new solder. Just heating the solder joint back up won't fix the problem long term. You'll need to do that to all the PCB in the CPU on any joint where a plug terminal or relay terminal attatches to the board. I also recommend doing the buzzer and other larger components on the boards.

goblues24

oops when i said logicon i meant the idiot box. icemark thanks for the info. im getting ready to try it out. ive got my soldering iron, solder, and desoldering braid.

this fix might get my keyhole light back on? thatd be cool.

bauer

Icemark

Key hole lights only work with a FB05 CPU, most 'verts came with FB01 CPUs (which can be modified to work the Keyhole lights.)

HAILERS

*Key hole lights only work with a FB05 CPU*.....now thats someone you don't ever want to play RX-7 TRIVIA with!

BadBoy

yup...or you want him on your team...:P

Fred

goblues24

i pulled a big black box out from behind drivers side kick panel next to fuses. theres a big white stamp on it that says "FC01" the print on it says c p u and talks about the flasher and turn signals and hazrds. i hope this is the right one....anyone tell me?

thx

bauer

goblues24

did the cpu resolder for the FC01 cpu. it only had two boards to do correct? i saw instructions on fc3s how to section that showed a cpu with 3 boards. my car works like it used to but a few strange things happened

i also fixed my passenger window regulator, as i was reattaching all of the plugs my horn beeped once (like an armed alarm would) after this i removed and resoldered the cpu..and replaced the "room" fuse. after plugging in the cpu i heard the proper beeps and stuff...yeah, but wait..then i started the car made sure everything was proper. now i get no beeps..no seatbelt light and no factory alarm. so i resoldered the whole thing again and made sure no joints were bridged(that shouldnt be). still not any beeps or belt light or alarm.

my question is do i look elswhere to resolve this or do i need a new cpu?

i especially want to thank everyone for help.

bauer

goblues24

bump

Icemark

does the dome light work normal???

goblues24

yes

HAILERS

http://www.mazdatrix.com/o86elect.htm

goblues24

icemark i tracked down the strange grounding and spliced wires. the ground on the door does not have anything to do with power windows, its spliced into the drivers side power lock control, i noticed that with the passenger side power lock disconnected, if i operate the drivers side lock it actuates the passenger side. so 1 down...as for the spliced black wire it is spliced at the green drivers side door harness, it to goes to the drivers side lock but goes to the handle. any ideas why when the door was replaced they had to wire it like this( maybe they accidentally broke through it when reinstalling?)

now for the better news...

after hearing my beeps and seeing the security flash to life for a split second, i decided to try again to fix it. i took the cpu out again and started unsoldering the diodes(or whatever they are)and some of the other little gadgets on the big board(after consulting with the shop manual wiring diagrams ala fc3s.org) i resoldered it up again with no luck. then i took apart the steering column and messed with the ignition and key light, then took out the stop fuse and put it back in, thinking i had failed i put the cpu back in the car and whala everything works now!!! yippeeee!!! i finished up at about 530 am and tested my security. i opened the door from the inside to set off the alarm, but when i went to deactivate it by putting the key in the door it would not stop going off..damnit(at 530 am my neighbors dont want to hear my alarm going off)after about a minute i unplugged the big plug to the cpu and it went off..finally. guess ill have to work on that. later in the afternoon of coarse.

i feel like the king of the world now!!

my only unresolved issue is after removing the glove box and checking the light and relay, i cant seem to get that damn glove light to come on. any ideas?

thanks to all for the help! now if i leave my lights on accidentally i get the warnings...yeah!!

bauer

Icemark

Glove box light only comes on when the parking lights are on and the glove box door is open.

The key switch in the drivers door may be broken and that's why it didn't disarm. You may try the key in the passengers door as well as it should also disarm any 88 and later FCs with the stock security system.