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Discussion Starter #1
My angel eyes stopped running the other day (I am using Daeos Vista harness). I decided to check the voltages to see if a fuse blew or the relay went out. I did some probing and read only 4.88V on the line to the angel eyes. I know it's supposed to be 12V. I popped open the ECU cover to where I tapped the accessory line (red wire with white stripes)...I measured it directly off of the tap from that wire and it read 4.88V (thus eliminating anything down the line...i.e. the harness). Does anyone know what can cause this low voltage reading on the red wire with white stripes in the ECU? Bad fuse? Or worse?

Thanks!
 

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Discussion Starter #3
A cause: Lower resistance than designed for. Did you check your bulb? Disconnect the wire of interest before measuring?
Yes. I disconnected the wire that goes to the Daeos relays (and ultimate taps to the angel eye wiring) before measuring voltage. Also, bulbs are fine...the angel eyes are on at correct brightness when xenons are manually set to on (i.e. right most switch position).
 

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Yes. I disconnected the wire that goes to the Daeos relays (and ultimate taps to the angel eye wiring) before measuring voltage. Also, bulbs are fine...the angel eyes are on at correct brightness when xenons are manually set to on (i.e. right most switch position).
Maybe your ground reference isn't what it should be.

Also, if not functioning, how did your test bulb?
 

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Discussion Starter #5 (Edited)
Maybe your ground reference isn't what it should be.

Also, if not functioning, how did your test bulb?


Tested bulbs by activating xenons (the AEs along with the side markers come on when the low beams are on).

In any case, I figured it out. I pulled the circuit diagram and figured out a fuse was blown later down the line. 10A fuse in the ECU box (it drives the accessories 12V line as well as DME fan, DMTL pump, flaps, etc.). Replaced it and boom voltage back up to 12V and all is well. Not sure how it got blown. I'm gonna give the wires a more thorough look over tomorrow to make sure there's no exposed copper that might induce arcing...
 

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Tested bulbs by activating xenons (the AEs along with the side markers come on when the low beams are on).

In any case, I figured it out. I pulled the circuit diagram and figured out a fuse was blown later down the line. 10A fuse in the ECU box (it drives the accessories 12V line as well as DME fan, DMTL pump, flaps, etc.). Replaced it and boom voltage back up to 12V and all is well. Not sure how it got blown. I'm gonna give the wires a more through look over tomorrow to make sure there's no exposed copper that might induce arcing...
... I'm kinda wondering how you got a 5V reading when the fuse is blown on the circuit.
 

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Discussion Starter #7
... I'm kinda wondering how you got a 5V reading when the fuse is blown on the circuit.
I was wondering that too...I did the measurement with the car in radio readiness mode (ignition without engine running). It read 4.5-5V then. I tried again with the engine running and that line read essentially 0V (~0.1V to be precise). Maybe it's leakage from another circuit when the car is off? Your guess is as good as mine!
 
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