spectre6000

iTrader: (1)

I resoldered my CPU last weekend, but due to uncooperative weather I only just now got it back in the car. The reason it got resoldered in the first place is that the what I think was the door buzzer beeped intermittently, with no regard to whether or not the door was open, and sounded like a dying giraffe when doing so. I think it was the door buzzer because it would come and go in a manner that seemed to be correlated to the door being opened and closed (though it could have been the vibration from the door closing jarring something internal somehow).

Now the door beeper works beautifully with nice crisp beeps that are directly correlated to whether or not the door is open, but there's a new beep that I can only track down to being related to whether or not the battery is connected... I recall in the moldy '88 owners manual I dug out of a salvage yard that there is a key for what the beeps mean, but getting my hands on a legible and year specific owners manual has proven to be impractical. I took some video in hope that someone could help me decipher what the CPU is trying to tell me so that I can fix that thing.

WhatsAWankel86

electronics are not my specialty but it seems like you have the "door closed" crossed with something else.. maybe you resoldered something together by accident?

satch

iTrader: (1)

Look in the FAQ as it lists what the number of beeps means.

spectre6000

iTrader: (1)

The only way anything could be crossed in any way is if it's internal to one of the logic chips. I double checked my solder work, then had my electronics guru friend double check my work. There is a bit of a nastiness to the fast beeping, so I do think something is shorting somewhere, but I have no idea where or what it could be. I'm really hoping someone knows what the beeps mean or has access to an '86 owners manual.

I don't know what year is intended to be represented in the FAQ, but 2 beeps means the door is open on mine and it says zilcho about endless fast beeps.

satch

iTrader: (1)

If the beeping is continuous then it is not two beeps. I tried watching your video but there was an error. So, tell us does the beeping resemble the same beeping w/the door open? If it does then opening the door w/the lights still on makes the same beeps. Also, try jiggling the key a bit in the ignition switch if that's where the key is when the beeping commences to see if the beeping can be stopped.

spectre6000

iTrader: (1)

If the battery is unplugged, nothing happens precisely like nothing should.

If I plug the battery in, it begins the fast continuous beeping.

If I open the door, it changes and only beeps twice. This sounds to me like it's trying to tell me the door is open. It did this before I did anything as well. Close the door, it goes back to the fast beeping. Depress the door button/sensor thing and it changes, and vice versa.

If I start it, it starts just fine. The fast beeping continues. Jiggling the key (and any manner of other things) changes nothing. Just fast beeping. The only thing that will change it is if I open the door or "open" the door (let go of the button). Lights on and off, turn signals on and off, wipers on and off (still need to do the wiper switch itself), etc. changes nothing in regard to the beeping.

Before I resoldered things, the clock was very intermittent in every way; sometimes it would light, sometimes it would keep time, sometimes neither, I could adjust the hours not the minutes. Now it lights consistently, but it is still only able to set the hour. It looks like the diagnostic setup experienced some nasty shorting at some point, so this is not a surprise.

Additionally before, the CPU would intermittently beep when the car was off. It would beep whenever it felt like it, but it was very weak and feeble and would occasionally be loud, occasionally not, etc. Additionally, the turn signals would only occasionally cancel (my previous vehicle did not have self-canceling turn signals, so it wasn't much of an adjustment for me, and I honestly barely noticed). Now they seem to cancel as they should.

Now it does the fast beeping constantly. I also noticed the blower motor for the AC system no longer turns on. I might have left something unplugged over there though, so I'm about to go check it out. It would blow before, but the compressor wouldn't turn on. Additionally, some of the lights in the control unit didn't work. I tested the LEDs individually, and they were themselves good. The AC light still doesn't come on when the button is pressed...

satch

iTrader: (1)

Sounds like the CPU board related to the beeping has seen better days. Perhaps a replacement is in the offing.

spectre6000

iTrader: (1)

Well, there are three boards in there. All were fully de/resoldered. The turn signals now seem happy, and the lights seem to be working just fine, so I did a reasonable job there. Looking through the wiring manual for an '88 (the only one I have access to) tells me that the only thing the third board contains that I actually need is the horn relay and the alt warning light relay. The rest is: light off reminder buzzer, key illumination timer, seat belt timer & buzzer, and key reminder buzzer. Let's say I were to plumb in a few FLAPS relays into the two I care about and scrap the rest. Anyone see any reason that wouldn't work?

The biggest and most mission critical reason would obviously be any difference between '86 and '88, and I know there are plenty of them...

spectre6000

iTrader: (1)

I have officially verified that the '86 CPU (and associated pinouts, schematics, etc.) are completely different from the '88 model year materials that are readily available. Is anyone aware of the existence of an '86-specific manual or wiring schematic available for download anywhere? I need to figure out what's happening here, and the '88 manual is too different to accomplish the task without hours of guesswork. What's the part interchange with the CPUs should I need to locate a new one?

j9fd3s

iTrader: (3)

for the 86-88 Rx7's there are two different CPU's.

FB01, and FB05, there should be a big white stamp on the thing

out of the 3 circuit boards in the thing, the main one is the different one, the smaller flasher, and lamp check boards are the same.

parts catalog says the FB01 is base/LX <-you!/SE/sport, the FB05 is GX/GXL/Turbo.

spectre6000

iTrader: (1)

Verified: FB01. The board I'm having issues with is the one with the beeper; aka the big main one with the plug on the side (versus the two on the bottom is installed in the car).

Any idea where I could find a schematic for it? The one in the readily available manual is clearly not the same. I've got a short somewhere in something, but I'm flying blind without at least an indication of pin out.

I don't know if I have a short in the CPU itself (I screwed something up when I resoldered it), or if I fixed the CPU such that I am now being told I have a short somewhere else that has been there all along and it just didn't function well enough previously to inform me (however annoyingly) of the fact. The only thing I'm fairly certain works like it should on that particular board is the door open beeper. The other two boards appear to be happy as can be...

j9fd3s

iTrader: (3)

you might look in the shop manual, section 15.

i know the doors beep, headlights beep, and the power steering, oil level and coolant level can beep, but i think that is actually it

spectre6000

iTrader: (1)

If we're talking about the same shop manual wherein section 15 is divided into two sections (body electrical system parts 1/2), then it's not correct for my car. There's only one CPU detailed, and it's not the one I'm looking at.

rotary_bünta

iTrader: (3)

that doesnt sound like beep.. its more like a chirp.

after hearing it over and over.. it def sounds like a chirp. almost like a dying alarm. sound... that's just my observation. lol hope it helps.

spectre6000

iTrader: (1)

No alarm. It is undoubtedly the CPU beeping. If you think it sounds bad in the video, you should have heard it before I attempted to resolder it... It was the most dramatic piece of car I've ever seen! "Beep! Boop! Oh I'm dying... booeerp booerp beep! [silence]" It's got a bad ground coming from something... I'm not sure if I broke something internal, only partially fixed something that was broken, or if I fixed it enough to tell me something somewhere else is broken. The beeps don't correspond to anything in any manual I've been able to find (none of which are correct for my year), and I can't find a schematic to tell me what the pins go to in the harness.

If I can figure out what's going on in there, I can figure out how to either fix it and make what I have work, rig up something that's not subject to '80s electronics fussiness, or maybe even map out the board and have them repopped if there's enough interest.

j9fd3s

iTrader: (3)

http://foxed.ca/rx7manual/manuals/19...CAL_SYSTEM.pdf

page 15:23

spectre6000

iTrader: (1)

Yup. Wrong CPU.

Features of that CPU include:
-light off reminder buzzer
-key illumination timer
-seat belt timer/buzzer
-horn relay
-alt warning light relay
-key reminder buzzer

Features of my CPU include:
-door buzzer
-????
-????
-????
-horn relay
-????
-????
-constant obnoxious beeping for no discernible reason

The only thing that sorta kinda had an obvious correlation to the CPU before I fixed it was the door beeper. I haven't left it powered long enough to figure out any other features it may or may not have/have had.

The way I know it's wrong is because mine clearly and obviously has a door ajar buzzer, and I saw it listed as such in a physical book this past weekend (couldn't take it with me, but the guy is supposedly emailing me a pdf of a better version of the same manual... hasn't happened yet and I'm starting to think it might not).

satch

iTrader: (1)

Are the number of pins the same but the difference lies in the wire colors or does it go beyond that? I know the ground wires on the 86 are Brown striped as opposed to Black as they are for other S4 years.

spectre6000

iTrader: (1)

I edited my last post. See above.

j9fd3s

iTrader: (3)

the beeping your hearing isn't the key reminder buzzer? the book is correct i think. the JDM FSM actually has 3 more pages of troubleshooting for the CPU, but in Japanese...

you might want to check the inputs TO the CPU, maybe you've got a bad/dirty switch in the car, oh and the next page hints at several fuses, so you may check those too

spectre6000

iTrader: (1)

The fast constant beeping could conceivably be key related, but the two-beep beeping is very clearly and unequivocally door related. There's a little rubber diaphragm in the rear lower corner of each door protecting a switch which is actuated by the door. Before I resoldered everything, with the switch open, the beeper would beep sadly and erratically. Sometimes it would beep other times as well. Now, it beeps in two-beep sets 100% of the time when the door is open/switch open, and 0% when the door is closed/switch is depressed. It is a direct and unambiguous correlation.

I'd love to check the wires in/out, but I need to know what they do and where they go first or I'll only be able to find faults between the plug and where they disappear into the harness. The wires are colored, sure, but if I have no idea what they're supposed to do or go to, I'll just be looking at every wire throughout the car as it comes out of some part of the harness and have to check continuity since I have no idea if anything has been spliced internally (one lead to the CPU, one to a switch or sensor somewhere, and one to some other component elsewhere in a fork) or what have you. The manuals and associated schematics I have access to (the '88 manual) do not include any '86-specific information and there are very clearly significant differences.

satch

iTrader: (1)

It would be easy to narrow down some of the wires in the plug. If you pull the plug off of the alternator and w/key to on check the W/B wire at the CPU and see if there is 12 volts. Then ground the W/B wire at the alternator plug and see if the W/B wire at the CPU has a ground on it which then causes the Yellow/Blue wire in the CPU plug to have a ground.

There is also a 4th plug with four wires at the ignition switch (only plug w/4 wires)which contains the wires for the key reminder and illumination features. A continuity test would narrow down some of the wires in the CPU plug. If need be just pull this plug and see what if any affect it has on your beeping.

spectre6000

iTrader: (1)

You believe yellow/blue to be ground (that's an unusual color for ground...)?

Between what I know and what can be assembled from available context, I think the features on the board are as follows:

-door beeper
-horn relay
-alt light relay
-key beeper (no light)
-headlight warning
-seat belt warning

The first is a certainty from experience. The second two are assumed because they seem to be common to all the CPUs I've been able to find information for. The following two are assumed from the '86 specifications pdf in the sticky, however there are also suggestions of warnings for low coolant, oil, and fuel (these are present in the diagnostic cluster, but that doesn't mean there's not an associated beep). The last is a guess based on the presence of a plug on the DS seatbelt latch.

j9fd3s

iTrader: (3)

the fast beep is something being broken

the door beep it should only do with the key in the ignition.

there are only two! the upper models have lights for the door locks, other than that every 86-88 CPU is exactly the same.

satch

iTrader: (1)

The Yellow/Blue wire has a ground when the W/B wire has a ground. The Y/L wire runs from the alternator relay to the warning light box to turn most of the lights on. The wire itself is not a ground wire but just a conduit to either relay a ground signal to the idiot lights or a voltage signal and nothing else.