BATTERT LIGHT / BRAKE LIGHT after new alternator? Help
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BATTERT LIGHT / BRAKE LIGHT after new alternator? Help
hey guys, I just picked up an Evo 9 MR. The car has the Brake and Battery light on full time. The last owner told me it’s been on Sincd he replaced the alternator and has not gone away. I searched all over as I see the brake and battery light is a common sign that the alternator is bad. The car is charging and from what I can see in the MR volt gauge it’s at 14.5. I have checked the fusesble link on the battery and all looks well. Any ideas how to turn these lights off? Is this a possibility of running an aftermarket alternator and the electrical system wanting an OEM? Any info would be greatly appreciated, I don’t want to replace a good working alternator unless it’s the only way to clear those lights.
Whats the age of the battery? Curious if its time to replace?
Question, with the Alt light on, does that not throw a CEL? If so, clear any present codes
Wonder if this could be a ground issue?
Anyways, just throwing out some ideas
Question, with the Alt light on, does that not throw a CEL? If so, clear any present codes
Wonder if this could be a ground issue?
Anyways, just throwing out some ideas
14.5v is a little high for a running car. Is it at that voltage at idle too? Does it dip in voltage under load like headlights, defroster, etc.? Is the alternator an OEM or aftermarket/rebuilt unit?
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I just watched the gauge (not sure if its accurate or not) and when the headlights/ ac/ and wipers are on it does a dip down to 14v and teeters between 14v-14.5v. I hooked up my snap on scanner from work and tried to see if it showed any faults through a full scan but it shows no codes. I suppose ill try a volt meter later just to double check.
I just watched the gauge (not sure if its accurate or not) and when the headlights/ ac/ and wipers are on it does a dip down to 14v and teeters between 14v-14.5v. I hooked up my snap on scanner from work and tried to see if it showed any faults through a full scan but it shows no codes. I suppose ill try a volt meter later just to double check.
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Thread Starter
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From: Fairfield, CT
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From: Fairfield, CT
Voltage reference wire that runs from the battery to the alternator. Basically, the ecu saw 9v instead of 12v due to resistance and bumped the charge.
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I just put my volt meter to the reference wire to the alternator and it seems to be charging at 15v-15.3. I turned on headlights and Ac and it dips down to 12 and then back up to 15v. Is this due to a regulator issue in the aftermarket alternator?
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[QUOTE=Project_Broke;11839466]
It is high. So either the regulator, or the reference wire issue like I had would be culprits.
ahh okay. Im going to go a bit deeper into it and see whats going on. Thanks for the help Project_Broke! Ill report back with what I find when I do.
ahh okay. Im going to go a bit deeper into it and see whats going on. Thanks for the help Project_Broke! Ill report back with what I find when I do.