seadawg

This is a really question for the "been there and done that" folks (like Icemark, Aaroncakes, Micah, etc.), but maybe others will benefit from the discussion.

The vehicle is a 1990 GXL, fully loaded (alarm system, etc.), and everything works, except this .....

Here's the problem - Both headlights stay up, and cannot be manually lowered (with the adjusters under the lights) unless either the retractor fuse is pulled OR the headlight cluster switch is disconnected.

I had read in a search for this problem that some folks said to check the ECU - So, I pulled the side panel, disconnected both ECU cables, and the retractors would still immediately raise IF the retractor fuse and headlight cluster switch was plugged into the harness, when I reconnected the battery.

This problem occured when the son-in-law left the internal lights on, jumped the vehicle, but accidentally touched the jumpers backwards to the battery. He said he "quickly touched", and did not hold it to the vehicle for any length of time. And, the vehicle has been driven for about 4 months since this happened, with the only issue is the headlights won't go down.

So - thinking it is the headlight cluster switch, I flip to page T-24 of the FSM, test out the switch and EVERYTHING works as shown as it is supposed to with the switch. I then rule out a failed switch.......

Then, I think it's in the wiring harness, so I start checking things there. HOWEVER - I can use a jumper wire, and make everything work on the car, by completing the circuits thru the connector at the dash - Meaning, the lights go up and down when I complete the circuit for the headlight cleaner switch, etc. This now makes me think the wiring harness and ECU are OK....... So, I'm back to that headlight cluster switch .....

Sooo - I go back to page T-22 of the FSM, and I see a diode that I think would cause this problem if it failed "open" (D3). I disassemble the headlight switch (per Micah's excellent rotorwiki instructions), pop out the diode, but it is OK. I guessed wrong....It's OK, so I solder it back onto the board.

Since I'm now stumped, but I have the board separate from the switch cluster body. So, I plug it into the dash connector, reconnect the battery, and up pops the lights. Finally, I unsolder D4 (the diode that is supposed to make ONLY the cleaner switch control the retractor), and the same thing still happens - lights up when the switch board is plugged into the harness.

I'm still thinking it is something wrong on the circuit board, with either the headlight circuitry or the cleaner switch circuitry.

NOW - To my question - For those of you that have repaired these headlight switch boards, is there a schematic somewhere that identifies all of the components? - The FSM only shows the components, but not their identifiers.

I'm sitting with the circuit board, a pencil, and page T-22 making one, but I'd feel better if someone already had it somewhere. If not, I'll scan what I make, and get it out for the reference material, once someone like Icemark double checks it.

I really feel that I have a direct short or an open of a component on this board, but it has me scratching my *** - Thoughts anyone??

(Micah - I'll PM you separately, and get you whatever internal pictures you want of this switch, for your wiki too)

seadawg

Micah - Do you want me to e-mail you any pics of the internals of the headlight cluster switch for a 1990 GXL?

Anyone else - Do you want me to post them here for future reference?

I'm still troubleshooting my problem - Icemark gave me some things to check out - thanks. I'll post the outcome (to help out others), once I do them tonight.

I tried to edit out the first line of my original post too, because after I read it, it sounded like I only thought a few people could actually help me - my bad - sorry everyone. I was just trying to keep the post fairly short and clean, so that the mods could archive it later, if it would be helpful to others.

More to come from me, as I figure this problem out.

HAILERS

Did you read this very recent post? https://www.rx7club.com/forum/showth...&highlight=CPU

The ECU is not the CPU.

The ECU is under the carpet on the passengers side and has nothing to do with lights.

The CPU is shown in the picture I attached to the url above.

Do you also know about the OTHER switch directly above the headlight switch, the ALSO controls the retracting headlights?

seadawg

Good catch Hailer, thanks - - I posted incorrectly in my original post.

I had previously read your your comments in your linked post from today, and I have already tried disconnecting both of the CPU cables (each individually, and both at the same time), but the headlights instantly popped back up in all three scenarios (bottom CPU cable disconnected, top cable disconnected, both CPU cables disconnected).

The only things I've found that will make my headlights stay down is either removing the retractor fuse under the hood, or disconnecting the connector to the headlight cluster switch at the steering column.

So I'm thinking it's not my CPU at this point. I still have the driver's side kick panel removed though, just in case my voltmeter checks take me back to those connectors.

And yea, I went thru both switch checks in the FSM (the cleaner switch and the headlight switch). I can jumper the RD & RU points on the wiring harness to BA (with the switch disconnected) and the lights raise up and down normally. From the FSM diagram, the switch cluster itself combines the up/down functions from the cleaner switch and headlight switch to output at RD (retractors Down) and RU (Retractors Up) on the diagram. HOWEVER, I've went thru most of the switch components (the headlight/cleaner switch relay, diodes, capacitors and resistors only) several times, and cannot find anything open/shorted or out of spec .......... And, all of the tests shown in the FSM check out OK for the cluster switch too...........

Sooooo, I just got home from work, put on the work jeans, and I'm heading out to the garage to jam down to some ZZ Top and figure this sucker out. I'll get back online later tonight and post findings and updates.

seadawg

I couldn't get back out here last night, the RX7.com server must have been getting hammered with a lot of traffic. Anyway, I went thru the wiring (again), and verified that when I plug in the switch, I always have 12V between the red/blue wire and ground - which leads me back to a bad switch.

What has me stumped is that according to the FSM switch diagram, I'm getting all of the correct contact closure connections from the connector on my cluster switch.

I'll ask again - Has anyone ever found the detailed circuit schematic for the 2nd gen headlight cluster switch - meaning, one that will show the component designations and pinouts (d1, d2, etc., c1, c2, etc. ic1, etc., pins 1,2,3,4,5, etc.)?

I'll check back here after work, and bite the bullet this evening and make up a CAD sketch, and send it to the mods to hopefully archive.

HAILERS

I don't have a switch apart and never have had one apart. But it SEEMS that if you could located that Retractable Headlight Motor Relay shown in the jpg I attached to the other thread, that maybe you could remove that relay? And that would solve the problem?

That relay must be latched all the time since you already tried to remove the CPU's plugs and have the same problem.

Mabe IceMark has what you want. I think he used to work on/repair those (guessing).

EDIT: OOPS. Remove the relay and the thing won't work. Never mind.

I still think it's something to do with that relay.

seadawg

Here's the thing - I can power the relay (per the instructions in the electrical section of the FSM), and the RU and RD open and close as it is supposed to on the switch. That's why I initially thought the switch was OK - meaning ALL of the checks in the FSM for the cluster switch works out.

HAILERS

Have you ever connected up the headlight switch, but have the Dimmer Switch disconnected, and seen what happened? Dimmer switch being the one with the lever you pull to bright/dim the headlights.

seadawg

Yea, I originally only disconnected the headlight switch, but once I removed the dash housing (the section that holds all three switches), I've been only swapping in the headlight switch for the tests.

Meaning, with all three switches unplugged, the retractors stay down when the battery is reconnected - but when I unplug the battery, plug in only the headlight cluster switch, the light magically raise.

I've started a "full" schematic, and I'm gonna work more on in this weekend. However if it wasn't a 60 day wait for Icemark, I think I'd be buying me a switch (smile).

kynde

It sounds to me like the relay is still in contact while the switch is open. Or there could possibly be a small voltage leak causing the relay to switch on. I havent looked at the circuit board in quite some time so Im sorry I cant give more advice. This thread should definately be archived once the problem circuit is discovered.

Good luck.

seadawg

Yea, that's where I started, when I initially checked out the board. But he relay switched "clean", meaning open circuit on the relay contact(s) when it should be, and fully closed when it was supposed to be - and I powered the coil with a 9V battery for the test out of the relay coil - but that should not matter.

Anyway, I'm still convinced it is the switch, and the colored vacuum diagrams someone else created have inspired me. I'm about 25% thru making a full schematic sketch, and when I get done, I'll start another post for comments. I'm out on the net, trying to find the specs on the Tiako relay, the transistors, the ICs etc. now.....

Once I get the sketch complete, I'll look at EVERYTHING that could have got fried by reversing the voltage for about a second, because that is what caused my pain in the *** problem.

I grilled the son in law (again) this afternoon, and he assured me that he did not hold the jumper cable on it more than a second - when he saw the big spark, he knew he was connecting it backwards, and he pulled it away as quick as he could.

seadawg

I bring this thread to closure, in case others search and find it. Sorry guys, I gave up trying to reverse engineer a 17 year old cluster switch circuit.

I did get my problem fixed though. It was a combination bad headlight switch AND I needed to disconnect the green/black wire on the switch connector.

So here is what I learned -

1 - If your battery has been connected backwards (or while jumping the car it is connected backwards) and your headlights instantly pop up, try removing the green/black wire from the circuit first (either push it out of the connector, or cut it (leave enough wire so that you can resolder it possibly later).

2 - If removing the wire does not solve your problem, go to the FSM and do the checks on the switch for the retractor circuitry. You can use a 9V battery to cycle the relay that is in the retractor/headlight circuit, and you also need a voltmeter.

3 - If the switch SEEMS to check out OK, then check out the wiring - meaning, plug the headlight switch back in, and disconnect the headlights at their connector (near each headlight), then check to see if the voltages change as they are supposed to, on the headlight/retractor circuit. Meaning, flip the retractor switch AND the headlight switch individually, and see if the voltage changes with the 4 different switch positions.

4 - If the headlight connector switch voltages DON"T change, when flipping the headlights/retractors on and off, suspect BOTH the switch is bad, AND the green black wire needs to be removed from the circuit.

5 - Either keep working on the headlight switch until you repair it, or buy a replacement. Install the new switch AND remove the green/black wire at the connector, by either cutting it or gently prying it out of the connector with eyeglass screwdrivers - BE CAREFUL - you don't want to break the connector.

Anyway, that's what I went thru to solve my problem. It took both fixes to get the lights to cycle properly. I don't know what the green/black wire controls on the CPU

And, I owe HAILERS a big thank you for suggesting it, along with IceMark for his help too. Micah - pics are coming to you too, so that you can post them on your wiki for folks that have too much time on their hands, and may want to take off where I left off, on repairing headlight switches.