jjc508520

I'm starting a new thread regarding my headlight problem - hope this is permitted. I've now spent entirely too much time on this and pretty much out of ideas.
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Recap – projector enclosure with ballast installed along with rebuilt headlamp motors

Problem – all headlights are operational – but will only flip into the closed position

Last night I broke out the FSM, test light, and voltmeter. Summary of what I found:

The headlight motors have 12v applied at all times. They receive a “pulse” from the controller which signals them to open or close.

Starting with the output side of the headlamp control module (connector C2)

Per the narrative – the doors “open” when 576 and 578 are hot and 577 and 579 are cold. I verified that when turning the headlamp switch on that a pulse is sent and +12v is applied across 576/577 and 578/579.

What this does is to spin the motors clockwise (from the top) and spin the shafts counter-clockwise (viewed from the side). The way I have the intermediate link connected (perhaps not correctly) is that this rotation of the motors caused the doors to close rather than open.

So one possibility is that I have the linkage improperly connected – but honestly I don’t see any other way it can go.

The doors are supposed to close when the polarity is reversed – and +12 is applied to 577 and 579 and then 576 and 578 are grounded. When I turn my headlamp switch off no pulse is detected.

Going to the input side of the headlamp control module (connector C1). When the headlamp switch is turned on +12 is supposed to be applied to 103 – and this was verified. When the headlamp switch is turned off +12 is supposed to be applied to 306 – and this was not verified. However – while the switch was in the off position – I connected a test lamp to 103 (the white wire) and although it did not light – the motors reversed direction and the headlamps moved to the Open position (the motor is spinning CCW when viewed from the above and CW when viewed from the side).

• Switch on – doors close and lights turn on
• Switch off – doors stay down and lights turn off
• Ground the white wite – both doors open
• Switch on - doors close and lights turn on

There is a show I want to go to on Long Beach Island next weekend – but unless I can get this sorted soon I won’t make it. Thanks again for your time...

STRMLNE

Sounds like you have the arm connected to the motor the wrong way. Try flipping it.

jjc508520

It just didn't look right to me - but I'll give that a try...

GCG

It is not my intention to nit-pick, but that is not accurate and could take you in the wrong direction.

The headlight motors do not have power applied at all times. It is the HDCM the one that is always hot and cuts power to the motors when they reach the end of their travel and a high-current threshold is met. The control signal to open or close is sent by the MFS to the HDCM and is not a pulse: it applies constant +12v to the "Open" signal wire and ground to the "Close" signal wire to command the doors to open, and the other way around to close.

Installing new headlamp housings shouldn't have caused electrical problems, unless you modified the wirings. Most probably this is a mechanical problem. If you are going to try to reverse the linkage, I suggest you try it by hand first using the motors ***** to see if it can freely open and close. You don't want to apply the full force of the motors and cause damage if the linkage is wrong.

NOTE: below is a summary of how things work in case you need to further troubleshoot this.




Power Sequence
BAT voltage is constant to Headlamp Opening Door Actuator Control Module (DACM) from the HDLP MOT L MiniFuse #4 (CKT 2940) and from the HDLP MOT R MiniFuse #3 (CKT 3040).

Headlamp Switch to HEAD position:

• BAT voltage is applied to Headlamp ON Input on DACM via CKT 103.
• LH door opens with BAT VOLT to LH opening door assy via CKT 576 & GND is applied to CKT 577.
• RH door opens with BAT VOLT to RH opening door assy via CKT 578 & GND is applied to CKT 579.

When HL switch is OFF:

• BAT voltage is applied to Headlamp OFF Input on DACM via CKT 306.
• LH door closes with BAT VOLT to LH opening door assy via CKT 577 & GND is applied to CKT 576.
• RH door closes with BAT VOLT to RH opening door assy via CKT 579 & GND is applied to CKT 578.

The Headlamp Opening DACM (front RH side below RH HL Assy) is grounded by CKT 150 via Splice Pack#100 (forwardlamp harness, attached to G102 - Point #8 in diagram below).

Bill Curlee

GCG!!! Very Well Stated!!..

BC

jjc508520

What I need at the moment is a better understanding of where the link is supposed to be positioned. Is it supposed to be hitting the fronts or backs of the bump stops? A or B?

jjc508520

It’s definitely ‘A’ - so I’m back to where I’ve been stuck for a week - no matter how I connect/position the arm the motors spin only one way. At one point I had them up and turned on - but not going down...

jjc508520

OK I have figured it out. The inputs to the headlight control module are correct based on the position of the headlamp switch - The problem is with the outputs - the top and bottom are hot and the middle two are cold regardless of the headlight switch position.

Also when walking into the garage I have heard a funny sound that I have been unable to track down - well it’s the headlight control module and it’s vibrating to some degree when the switch is in the off position - if I put my hand on it I can actually feel it!

I guess these things are not repairable?

Thanks everyone for your patience

jjc508520

jjc508520

There are 4 contacts on the relay - and none are moving in either position - it just hums

Bill Curlee

Better get a new module... They are VERY EXPENSIVE!

GCG

It should hit the "back" of the bump stops and as the door closes the "knee" should bend forward. Seems like "A" in your pictures.


Your HDCM is not looking good... Power to the outputs (connector C2) should be cut off after the doors finish opening or closing. Motors can't remain powered.

But in addition to that there seems to be a conflicting behavior. According to your readings from connector C2, "the top and bottom are hot and the middle two are cold regardless of the headlight switch position". That translates to this:

• Pin A -> LT GRN -> CKT 576 -> +12v
• Pin B -> DK GRN -> CKT 577 -> ground (if by "cold" you meant 0v - it's better to always write actual voltages)
• Pin C -> DK BLU -> CKT 579 -> ground
• Pin D -> LT BLU -> CKT 578 -> +12v

And with those settings applied to the motors the doors should OPEN, not remain closed!!!

Hey, no worries, what's important here is to get to the bottom of this

jjc508520

https://www.ebay.com/itm/97-04-Corve...e-4cab68f88440

C5 Diag

the show is on June 8th..,you have a few more weeks !!

dood73

Hope you get it sorted out. I've got my own little problem with my headlight buckets and it is a bit of a head scratcher.

jjc508520

There is a smaller event I’ve heard about - at the new mini-golf course opened by a friend of mine up at Barnegat Light...

jjc508520

Well I am no closer than I was before. With the new headlight module installed I am still not getting correct polarity to cause the headlight motors to switch direction. They will spin only clockwise - pulling the lever back and closing the headlights - this is with the switch in the on position. The attached movie shows what happens when I turn them on. Turning them off does nothing. Link is to a short movie on my One Drive...

https://1drv.ms/v/s!AkYiM3p-XVDUlXO4J1ysDw9hjunr

jjc508520

Inputs to the headlamp module

switch off switch on
103 cold hot
2940 hot hot
306 hot cold
150 cold cold
3040 hot hot

From what I can tell this is correct - switch on/off connectors 103 and 306 should reverse.

Outputs from the headlamp module

switch off switch on
576 hot hot
577 cold cold
579 cold cold
578 hot hot

This is bad - 576/577 and 578/579 should reverse.

I connected leads directly to the battery and was able to make the motors switch directions - but not through the switch.

Wild card - could any of this have to do with El Cheapo HID ballasts? I noticed that even the new module I got is "humming" when everything is off - when I disconnected the leads from the ballasts to the low beams it seemed to stop. These are Xendrive - will look to see if anything better is available locally.....

jjc508520

Got it - put the Sylvania HBU bulbs back in and now the motors go both ways. I guess the resistance of the HID ballasts are not enough. I’ve read enough in other posts to hopefully figure thuan out.

As one reply said - ‘Electricity is a strange thing!’

jjc508520

Except - they are opening when they should be closing