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Fiero headlights go up but not down by Benn2002
Started on: 04-18-2021 02:45 PM
Replies: 8 (374 views)
Last post by: theogre on 04-19-2021 06:21 PM
Benn2002
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Report this Post04-18-2021 02:45 PM Click Here to See the Profile for Benn2002Send a Private Message to Benn2002Edit/Delete MessageReply w/QuoteDirect Link to This Post
It's a 1988 formula, looks like stock motors and headlights. they go up fine, I can put them down manually, but not with the switch. The headlights work , turn on just fine, it just seems to be stuck up. They worked a week ago, drove the car once and they didn't go down. I checked the TAIL fuse, and it was fine. Any help is greatly appreciated!
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Chris Eddy
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Report this Post04-18-2021 08:49 PM Click Here to See the Profile for Chris EddySend a Private Message to Chris EddyEdit/Delete MessageReply w/QuoteDirect Link to This Post
It could be so much, but I just went through this, and can pitch some thoughts..
I am assuming that the 88 has the same electronic "second generation" stuff..
The controller board is in the fender cavity, drivers side.
If you take the trim strip off of the fender, take two more screws out, and then carefully reach in and get the two screws out of the module, you can wrangle the module out between the two fender panels and work on it in the air.
In my case, the terminals were getting crusty. Spraying some contact cleaner and seat/reseat over and over again cleared it up.
But meanwhile, you can test the voltages going to the module.
The 4 pin connector is for left and right motors.
The 5 pin connector has 12V, ground, close, 12V, and open signals. I might have open and closed reversed.
If you pull the connector, 12V and ground are all measurable.
And based on the position of the light switch, the open or the close wire have 12V on them.
If all of that works out, and you clean the terminals really well, then you are down to the motors or the module.
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fierofool
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Report this Post04-18-2021 09:25 PM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
I would look at the light switch. There are two hot circuits in the switch. One is for up and the other for down. If the contacts wear or corrode, that circuit may not work. Switches are available at most auto parts stores. Or, you can very carefully take the switch apart and clean it. I say very carefully because little springs can go flying everywhere.
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WalkerTexan
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Report this Post04-19-2021 01:32 AM Click Here to See the Profile for WalkerTexanSend a Private Message to WalkerTexanEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think FieroFool is on the right track. Assuming no one has fiddled with the module in the past then there are two separate circuits; one for driver's and one for passenger's motors. For both sides to fail would mean both circuits in the module are bad which is much less likely. The same wire connections from the module to the motors are used for both Open and Close so if it opens normally without any hesitation then those wires/connections are probably OK because the module swaps them to change direction. Not impossible, as Chris said he's had a similar issue, but seems awfully coincidental that Closing them is a problem on both sides yet open is fine on both sides.

The common failure point would be the light switch or wire to the module because it uses two 12V wires; white one is at 12V when all lights are OFF and is floating when the lights are ON. The second one is yellow and is at 12V when the headlights are ON and floating when they are OFF. The red wire at the switch is the 12V source for both the white and yellow wires.

I suspect the 12V is bad on the white wire when the lights are in the OFF position because that is the signal to the module to close the headlight doors. I would check the switch first because it is much easier than getting to the module. Remove the switch panel and then unplug the switch. Set the switch aside. Use a wire to jumper the RED wire connection in the car plug to the YELLOW connection in the plug and the headlights should open, Remove the jumper wire once they are fully open and the headlights should remain open and the bulbs themselves will be OFF. Then jumper the RED to the WHITE connection and the headlights should close. If they do then the switch is at fault. You can use a meter to check continuity through the switch to confirm it is bad or maybe just a bad connection. There should be continuity between the connection that mates the red wire and the white wire when the switch is OFF and it should open when the switch is ON. Conversely, there should be an open between the red connection and the yellow when the switch is OFF and continuity when the switch is ON.

Should the 12V signals be correct at the switch then the next thing is to check that those signals are making it to the module. The yellow wire certainly is since they do open. A break or corroded connection in the white wire at the module would cause this failure just like the switch would.

Hope this helps.
Michael

[This message has been edited by WalkerTexan (edited 04-19-2021).]

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Benn2002
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Report this Post04-19-2021 07:43 AM Click Here to See the Profile for Benn2002Send a Private Message to Benn2002Edit/Delete MessageReply w/QuoteDirect Link to This Post
Thank you guys for the feedback and right after work today I'm going to rip open that switch and get those working again (hopefully haha). Hopefully just the switch but if i gotta go to the module Its gotta be done. Thank you guys!
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fierofool
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Report this Post04-19-2021 08:00 AM Click Here to See the Profile for fierofoolClick Here to visit fierofool's HomePageSend a Private Message to fierofoolEdit/Delete MessageReply w/QuoteDirect Link to This Post
Autozone sells a headlight switch that's the right color combination. Duralast Part # SW235. $17.00. After checking the circuits as WalkerTexan described, I'd just grab a new switch. I have had one from somewhere else, and it was all black. It quickly failed so that it would only move the headlights half way up without a second harder push. I think it was from Rock Auto. The Duralast switch has a good solid feel to it.
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theogre
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Report this Post04-19-2021 03:06 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
See my Cave, Gen 2 HL Motor for Correct Wiring.

Pull HL Switch off the socket.
On the socket, jump orn wire to white wire. should go down.
If not, jump Red to white. should go down.

If orn to white goes down then likely switch has problems.

If red make them go down then something in Taillight circuit have problems.
Check Orn wire for "12v" on the socket. (neg probe to frame of car anywhere handy.)

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[This message has been edited by theogre (edited 04-19-2021).]

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Benn2002
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Report this Post04-19-2021 05:25 PM Click Here to See the Profile for Benn2002Send a Private Message to Benn2002Edit/Delete MessageReply w/QuoteDirect Link to This Post
So update, got home from work, took the switch apart clean it, put it back in, didn't work lol....so I took it back off, used a wire to connect the RED to the WHITE, I got nothing. Motors didn't even flinch. No spark either, which is odd to me because putting them up it sparked, any more ideas??
I just didn't think the module would be bad but maybe it is who know..
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theogre
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Report this Post04-19-2021 06:21 PM Click Here to See the Profile for theogreClick Here to visit theogre's HomePageSend a Private Message to theogreEdit/Delete MessageReply w/QuoteDirect Link to This Post
You won't get a spark "turning on" the module up or down. Spark for up likely the HL bulbs... Yellow wire is Power for HL Bulbs too. They draw a lot of power.

The module likely have problem or a loose/bad connection on white wire.
Next is either:
Carefully pull up soft plastic seal on 5 pin connector at the module. Leave the plug alone and plug in. May need to pull or cut black plastic "tape" to have slack to pop out the seal.
● Alternate is "back probe" the white wire. 1. find a large sewing pin. 2. make sure you get 0 Ω on the pin. Many are "painted" or otherwise won't work. 3. Carefully push pin next to white wire (Wire Holes in the Soft seal will should move to allow pin to move w/o making a new hole.) and carefully move the tip as needed until you have "12v."

Again Check for "12v" on white wire. (Jump the switch socket or make sure switch works for down wire.)

Have power there?
Then carefully pull push or wiggle the plug.
If motors try to move or completely move down, Pin(s) likely have solder cracks to the module board.

The pins often have cracks there because of iffy manufacturing. If happens, can be fix but not w/ crap or other small tools most have.
Small/cheap irons, < 25w, often will make more problems heating large pins and "lift" the copper of the board overheating that.

E2A--->Other big pins likely have solder cracks too but may not be very obvious. If I rework a large pin then I do all big pins before testing. In this case the 4 for motors and the 5 for power side.
If board has other problems see cave notes to repair... most repairs are Not a good idea beyond fixing crack joints.

[This message has been edited by theogre (edited 04-19-2021).]

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