ex240sxEF9b16AT85c4

Hey everyone. recently i bought replacement headlight motor gears for both sides of my 85 from ecklers. now i'm questioning if i needed them. and not a new motor.

History: i've been putting these off for over 2 years now, since i do little night driving. but it's always bother'd me. originally both lights would come up but only 1 would go down, now both won't even go up. no noise from motors or anything.

i've replaced my relay's about a year ago, and can hand crank them up and down using the **** at the lower of the headlight motor (closest to front bumper) which is making me question if my gears are even bad and possibly it's the motors.... now before i go installing both sets of these (i was currently removing the pass headlight when i decided to post). i want to make sure i shouldn't just return the gears and send out my lights to have them overhauled by ecklers instead.


any info would be greatly appreciated. thanks in advance. any questions feel free to PM or reply in post.

AGENT 86

Are the relay's sending voltage to the motors ?? Maybe it's an internal limit switch problem.

ex240sxEF9b16AT85c4

ok motor has 3 wires w/ clip on top say ( (a) (b) (c) )

ign off switch off

a 12.69v
b 0.013v
c 0.002v

ign off sw on

a 0.25v degrading (going down)
b 0.041v
c. 12.06v

ign on sw off

a 12.2v
b 0.013v
c 0.023v

ign on sw on

a 0.5v degrading
b 0.062v
c 11.83v

all measurements taken from harness side connector w/ my fluke meter grounded to battery neg.

one thing i can hear when i pull the switch is my relays click

1989vette

if you decide you don't need them let me know, i need new gears myself.

nitronick

If it was just the gears, you would have a spot where the headlight would flop back and forth until you got it to where the gear had some teeth for it to grab while you were hand cranking it. At least, that's what mine does.
Since you have replaced relays, I would guess it's the motors. If they were ok, surely they would make some noise...

ex240sxEF9b16AT85c4

Thread resurrection!!!

Cars been in storage for years, going to attempt to fix this again... hoping and thinking it's the relay, wondering if i can send 12v to the motors direct and get them to work just to test.

ccrazor

Have you checked your grounds to the motors?? Try the same tests with the meter connected to + of battery, there are two contacts in the motor also, one of which will be normally operated open when the light is closed..

ex240sxEF9b16AT85c4

so the relays are all definitely clicking. the passenger side light tho is not getting 12v... and the connector looks slightly blackened at the red wire on the harness side at that headlight connector... >.<

according to the 84 wiring diagram in another 85 headlight issue thread going on right now the 12v should be coming from the isolation relay and fusable link G to the red and dk grn/wht wire correct?

once i get the voltage sorted out to the passenger side i'm pretty sure i'm going to find that both motors are done sucks because these lights use to atleast do something but now do nothing

I'd love to know if it's possible to test these with an external power supply of some sort. that would pretty much spell out the answer for me.


Edit: I checked the ground wire (greens) at the harness side of the motor connector with the headlight motors disconnected and they check out good for continuity.



Some pics of the inside of one of the motors when i had it apart to check the gears: (looking back at it now those contacts look terrible)

ccrazor

If the other motor looks like that, I would say you are due for motor rebuild. The brushes have next to no life left, the commutator (section of armature that brushes run on) could do with a good clean..

ccrazor

To test the motor out of the car, put 12v on the grey wire and ground on the green. To check the other way put 12v on the green wire and ground on the white..

ex240sxEF9b16AT85c4

awesome info thanks! i'll try that in the next couple days.

ex240sxEF9b16AT85c4

Btw any thoughts on the lack of voltage to the passenger side headlight? I'm using the FSM page you linked in another members thread. thanks!!!

ccrazor

With power off you should have power on the grey wire at the motor, through the normally closed contacts of the isolation relay, right from the main light switch, ground is applied to the green wire through the RH actuator relay from G106. When you turn the light switch on you get power to the green from fusible link G through the operated contacts of the actuator relay, and ground on the white through the other operated contacts of the same relay and G106..

ex240sxEF9b16AT85c4

yea i'm getting no voltage at all on the RH harness side connector.

ccrazor

If you have power to the grey wire on the drivers side then your switch should be good. Check for power at the isolation relay. If the relay has terminal designations and you have power to the socket you could insert a jumper in B and D, and check for voltage at the connector.. If this works you may be able to open the relay and clean the contacts as a temporary fix..

ex240sxEF9b16AT85c4

you sir are a wealth of knowledge!!