928 Headlights have their own mind
#16
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You should be able to read all feeds from the headlight switch at the Central Electric unit.
Same with all 4 feeds to the headlights themselves (post fuses).
Do you have the wiring diagrams for the 82?
For the headlight feeds
M1 (at CE panel) = 56a Left Side, Wht/blk (@ headlight bucket), Fuse 24
M2 = 56a Right Side, Wht, Fuse 25
M3 = 56b Left Side, Yel/blk, Fuse 26
M4 = 56b Right Side, Yel, Fuse27
For the motor feeds (which sound like they are working fine)
N8 brown/red = 30b at motor = 30bm at relay
N7 white/black = 56 at motor = 56 at relay
N6 green/yellow = 86 at motor = 86m at relay
N5 red/black = 30 at motor = 30m at relay
For the dimmer switch
B1 at CE panel = 56a at dimmer switch
A1 = 30
For the light switch itself
A2 = 30
B6 = 30b
B7 = 58
B5 = 56
B3 = 58L
B4 = 58R
You really need the CD's that Alan references. Be real careful with these circuits.
Have you checked the headlight bulbs themselves? Do you have power at M1,2,3 or 4 (they feed the high and low beams, r & l sides) and fuses (noted above)?
Same with all 4 feeds to the headlights themselves (post fuses).
Do you have the wiring diagrams for the 82?
For the headlight feeds
M1 (at CE panel) = 56a Left Side, Wht/blk (@ headlight bucket), Fuse 24
M2 = 56a Right Side, Wht, Fuse 25
M3 = 56b Left Side, Yel/blk, Fuse 26
M4 = 56b Right Side, Yel, Fuse27
For the motor feeds (which sound like they are working fine)
N8 brown/red = 30b at motor = 30bm at relay
N7 white/black = 56 at motor = 56 at relay
N6 green/yellow = 86 at motor = 86m at relay
N5 red/black = 30 at motor = 30m at relay
For the dimmer switch
B1 at CE panel = 56a at dimmer switch
A1 = 30
For the light switch itself
A2 = 30
B6 = 30b
B7 = 58
B5 = 56
B3 = 58L
B4 = 58R
You really need the CD's that Alan references. Be real careful with these circuits.
Have you checked the headlight bulbs themselves? Do you have power at M1,2,3 or 4 (they feed the high and low beams, r & l sides) and fuses (noted above)?
Last edited by Landseer; 04-22-2008 at 12:06 AM.
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davek9 (05-26-2023)
#17
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Yes but I think the root of his question is - what should all these be doing under different conditions... its actually quite complicated - even to explain when you know...
My approach was to break the systems into major parts and create simpler circuit diagrams for each feature individually:
- The light switch modes
- The pod raising & lowering mechanisms
- The headlight switching mechanisms (incl Hi/Lo)
It still requires some comprehension of the systems from these but its much less confusing (especially when described).
I understand the schematics quite well but it took a while to comprehend how all the HL circuits worked - the schematics are very confusingly drawn (as are many - HVAC comes to mind). Even with this - the headlight relay (3 versions) are not described functionally and operation needs to be deduced based on understanding of the intent...
The debug can be impossibly complicated til you "get" this ...
Alan
My approach was to break the systems into major parts and create simpler circuit diagrams for each feature individually:
- The light switch modes
- The pod raising & lowering mechanisms
- The headlight switching mechanisms (incl Hi/Lo)
It still requires some comprehension of the systems from these but its much less confusing (especially when described).
I understand the schematics quite well but it took a while to comprehend how all the HL circuits worked - the schematics are very confusingly drawn (as are many - HVAC comes to mind). Even with this - the headlight relay (3 versions) are not described functionally and operation needs to be deduced based on understanding of the intent...
The debug can be impossibly complicated til you "get" this ...
Alan
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I have a set of manuals on CD but am not sure if they are the same you are referring to.
It came with the car. Looks like a ton of books that were converted to PDF.
Many of the wiring diagrams are not readable.
Do these CD's have an explanation of the relays?
Do you guys have a link to these CD's? I will buy them if they are in fact better and/or different that what I already have.
It came with the car. Looks like a ton of books that were converted to PDF.
Many of the wiring diagrams are not readable.
Do these CD's have an explanation of the relays?
Do you guys have a link to these CD's? I will buy them if they are in fact better and/or different that what I already have.
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A few days ago when I started all this I did jump across some of the relay contacts and the headlights did come on so bulbs good. I guess I need a better understanding of the headlight relay and how the whole X terminal and the logic works.
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Many of the wiring diagrams are not readable.
Do these CD's have an explanation of the relays?
Do you guys have a link to these CD's? I will buy them if they are in fact better and/or different that what I already have.
To your other post - yes figuring out how it all works is useful - for most people it never happens - there is just so much... Most folks focus on just fixing what is broken - that usually keeps them busy...
Alan
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I did a little more poking around. Where does the 86M get fed from?
to me from the drawings it comes from the headlight motor but its not labeled the same.
I pulled the headlight switch and all the contacts rang out properly according to my schematics.
The X bus is on with the key on.
Jumping 30 to 56a,56b light up the lights.
With the ignition on, pods up, switch in 2 what should I be reading on the following:
bm30, b30, x, 56
These feed some sort of logic circuit.
to me from the drawings it comes from the headlight motor but its not labeled the same.
I pulled the headlight switch and all the contacts rang out properly according to my schematics.
The X bus is on with the key on.
Jumping 30 to 56a,56b light up the lights.
With the ignition on, pods up, switch in 2 what should I be reading on the following:
bm30, b30, x, 56
These feed some sort of logic circuit.
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Ok so if the ignition is on, the pods up, light switch in 2 should the 86m be +12v with the relay removed?
If so where does it come from in the circuit. Does it come from the pod motor indicating proper position or does it come from another switch etc.
If so where does it come from in the circuit. Does it come from the pod motor indicating proper position or does it come from another switch etc.
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Ok this afternoon I wrapped a tiny wire around the 86m post and fed it 12+ and my pods went down.
Not what I was expecting.
I don't want to just start throwing parts at it but I might have to. Starting with the Combo relay and then the light switch.(easiest to do first).
Not what I was expecting.
I don't want to just start throwing parts at it but I might have to. Starting with the Combo relay and then the light switch.(easiest to do first).
#29
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So, it sounds like at least one of the relays within the headlight relay is either not energizing or not making contact once it does energize.
Some folks have taken the cover off the relay and cleaned the contacts.
I chose to purchase a new relay. This one costs about $110, so it is costly, but with it comes peace of mind.
Some folks have taken the cover off the relay and cleaned the contacts.
I chose to purchase a new relay. This one costs about $110, so it is costly, but with it comes peace of mind.
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I think tonight I will study the schematics a little more and do a few what if scenarios on paper to see if i can duplicate what I saw with the applied voltage to 86m.
Also I might look at the schematics for other years and maybe the drawings will be clearer.
Also I might look at the schematics for other years and maybe the drawings will be clearer.