suprunner Posted November 23, 2021 Share Posted November 23, 2021 (edited) So, I've recently come into a problem. I've noticed an intermittent whirring/whistling noise coming from the center/center-bottom of the dash. Almost sounds as if there's a cd in a disc-player rotating at a high speed. I don't have a cd-player, and I've also removed the fuse from the radio, and the noise still comes. Anyway, when the noise comes on, it follows the RPMs of the motor. If I depress the accelerator, the noise gets louder. While idling (and noise present), if I press on the brake pedal the lights pretty much completely cut out, and the motor almost dies. In the videos you can hear the noise, and see the idle responses. It frequency of brake-taps is consistent with the motor behavior. ALSO, if I turn on the hazard lights, the idling bobbing/cutting with the lights cutting follows the frequency of the hazards and/or turn signals. When the whirring goes away, the symptoms are gone. Do I all of a sudden have a really bad ground? All lights are functional; nothing out. '98 OBW with 251/25D hybrid Recent work (past 6 months): New OEM MAF New OEM TPS New OEM ignition coil New OEM plugs New OEM wires New OEM 5mt neutral switch New OEM 5mt reverse light switch New Fuel pump relay (symptoms were present before I went playing under the dash) Done in the past two years: fuel pump fuel filter Timing belt New OEM Cam Gears I'm pretty bad at electrical diagnostics, any suggestions/advice would help. Battery has 12.5v just sitting. 12.8v while idling. Thanks for your time folks, Greg Edited November 23, 2021 by suprunner clarification Link to comment Share on other sites More sharing options...
ronemus Posted November 23, 2021 Share Posted November 23, 2021 Your battery voltage at idle should be ~14V, so you either have something demanding so much current that the alternator can't keep up at idle or a bad alternator. It could also be a connection issue - try removing and re-seating the relevant connectors, and loosen then re-tighten the ground connections, and be on the lookout for corrosion, Link to comment Share on other sites More sharing options...
suprunner Posted November 23, 2021 Author Share Posted November 23, 2021 30 minutes ago, ronemus said: Your battery voltage at idle should be ~14V, so you either have something demanding so much current that the alternator can't keep up at idle or a bad alternator. It could also be a connection issue - try removing and re-seating the relevant connectors, and loosen then re-tighten the ground connections, and be on the lookout for corrosion, Thanks! I'll start looking. I have put "upgraded" grounding wires in and filed-off paint from the usual body-mounts (e.g. small ground off of battery, transmission-to-body-ground). The alternator is old, and has lived in the Las Vegas heat without a garage for the past two years. I'll check around. Thank you! Greg Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted November 23, 2021 Share Posted November 23, 2021 triple check battery clamps? the car will run for a little while with the alt belt removed. Might help with some diagnosis. corroded bake light connector (remove bulb, look inside socket), bad 1157 type dual filament bulb(drooping/shorted filament), or bad wiriing in the 'gaiter; from body to hatch may play into this. Link to comment Share on other sites More sharing options...
suprunner Posted November 23, 2021 Author Share Posted November 23, 2021 1 hour ago, 1 Lucky Texan said: triple check battery clamps? the car will run for a little while with the alt belt removed. Might help with some diagnosis. corroded bake light connector (remove bulb, look inside socket), bad 1157 type dual filament bulb(drooping/shorted filament), or bad wiriing in the 'gaiter; from body to hatch may play into this. I'll triple check again. Will running the car off of just the alternator for-sure fry it if it is under-charging? Or will that not have any detrimental effect? So, just the general harness for the rear lights/hatch? The symptoms show up with the lights-off AND with the hazards going. Also, Bosch or Denso Reman? Thanks! Greg Link to comment Share on other sites More sharing options...
brus brother Posted November 23, 2021 Share Posted November 23, 2021 alternator bench check? Link to comment Share on other sites More sharing options...
brus brother Posted November 23, 2021 Share Posted November 23, 2021 Just now, suprunner said: I'll triple check again. Will running the car off of just the alternator for-sure fry it if it is under-charging? Or will that not have any detrimental effect? So, just the general harness for the rear lights/hatch? The symptoms show up with the lights-off AND with the hazards going. Also, Bosch or Denso Reman? Thanks! Greg subaru re-manufactured may be available at reasonable cost. call around dealers. Link to comment Share on other sites More sharing options...
suprunner Posted November 23, 2021 Author Share Posted November 23, 2021 18 minutes ago, brus brother said: subaru re-manufactured may be available at reasonable cost. call around dealers. Subarupartsdeal states that the original part # and replacement part # have been discontinued. They purchase/supply from Subaru warehouses. Link to comment Share on other sites More sharing options...
suprunner Posted November 23, 2021 Author Share Posted November 23, 2021 3 hours ago, 1 Lucky Texan said: triple check battery clamps? the car will run for a little while with the alt belt removed. Might help with some diagnosis. corroded bake light connector (remove bulb, look inside socket), bad 1157 type dual filament bulb(drooping/shorted filament), or bad wiriing in the 'gaiter; from body to hatch may play into this. Found two bulbs on the passenger side that had corroding sockets. Unplugged them. While running, and lights off, voltage just continues to drop. Over a 10 minute period of idling, the voltage at the battery dropped from 14.6 to 14.0, even when I had the lights off, and any other accessory power-draw deleted. Safe to say my alternator is dying? Link to comment Share on other sites More sharing options...
lmdew Posted November 24, 2021 Share Posted November 24, 2021 Could be. Try pulling one fuse at a time and see if it isolates the fault. Link to comment Share on other sites More sharing options...
nvu Posted November 25, 2021 Share Posted November 25, 2021 (edited) On 11/23/2021 at 11:19 AM, suprunner said: Subarupartsdeal states that the original part # and replacement part # have been discontinued. They purchase/supply from Subaru warehouses. You don't need the exact alternator. I've thrown a '18 sti alternator in my 03 wrx. Just get the matching pigtail connector and splice it into the harness. Newer alternators have 3 wires, only two are used if it's an older model. As long as the alternator physically fits. You might have to get creative if the positive terminal is located differently between models. I'd say pull all the fuses and relays. Only leave enough in so the engine can start and run. Edited November 25, 2021 by nvu Link to comment Share on other sites More sharing options...
suprunner Posted November 30, 2021 Author Share Posted November 30, 2021 On 11/22/2021 at 6:22 PM, ronemus said: Your battery voltage at idle should be ~14V, so you either have something demanding so much current that the alternator can't keep up at idle or a bad alternator. It could also be a connection issue - try removing and re-seating the relevant connectors, and loosen then re-tighten the ground connections, and be on the lookout for corrosion, Is that voltage at idle no matter what the load? Like if I have the headlights, fog lamps, and rear defroster running, it should still be at about 14 volts? Greg Link to comment Share on other sites More sharing options...
idosubaru Posted November 30, 2021 Share Posted November 30, 2021 6 hours ago, suprunner said: Is that voltage at idle no matter what the load? Like if I have the headlights, fog lamps, and rear defroster running, it should still be at about 14 volts? Greg Yes. More devices require more amps, voltage stays the same. Link to comment Share on other sites More sharing options...
suprunner Posted November 30, 2021 Author Share Posted November 30, 2021 4 hours ago, idosubaru said: Yes. More devices require more amps, voltage stays the same. dang. I have work to do then. Thank you. Link to comment Share on other sites More sharing options...
suprunner Posted December 1, 2021 Author Share Posted December 1, 2021 @lmdew @idosubaru @1 Lucky Texan @nvu @ronemus I replaced the battery terminal clamps with marine-clamps. The copper of the battery cables were no longer shiny and had some oxidation, so I made brand new positive cable from battery to starter, and freshened up the cable/terminal connector from the positive coming out of the fuse box. Brand new ground cable from battery to starter/bell-housing, battery to front body, and battery to intake manifold. Volt meter now reads a stable 14.1 with everything on (fog lamps, rear defroster, heater, radio), except the headlights or hazards.I pulled the headlight relays and the volt meter went from 13.8 (and looked as if it were dropping) back to 14.1. I have the JDM projectors installed. I assume that I need to chase the grounds to the headlights? Or convert the H1 bulbs to LEDs? Both? Thanks for all of your help, Greg Link to comment Share on other sites More sharing options...
idosubaru Posted December 1, 2021 Share Posted December 1, 2021 You’ve checked all bulb sockets and pigtails related to headlights? Make sure no rear or front headlight, low beam, high beam, taillight are corroded or bad? disconnect each headlight and tail light one at a time and see if any impact voltage differently. If there’s more than one per assembly - disconnect each wiring plug in the headlight assembly independently and the entire tailgate if there’s easy access (some are easier than others). Im not familiar with JDM but if any custom wiring was done that’s the first place to start. I worked on a friends problematic headlights last week. Turns out previous shop reversed the wiring to a replacement bulb connector. Still worked but not correctly. Link to comment Share on other sites More sharing options...
suprunner Posted December 1, 2021 Author Share Posted December 1, 2021 5 hours ago, idosubaru said: You’ve checked all bulb sockets and pigtails related to headlights? Make sure no rear or front headlight, low beam, high beam, taillight are corroded or bad? disconnect each headlight and tail light one at a time and see if any impact voltage differently. If there’s more than one per assembly - disconnect each wiring plug in the headlight assembly independently and the entire tailgate if there’s easy access (some are easier than others). Im not familiar with JDM but if any custom wiring was done that’s the first place to start. I worked on a friends problematic headlights last week. Turns out previous shop reversed the wiring to a replacement bulb connector. Still worked but not correctly. Hey thanks for getting back! The JDM headlights have separate bulbs for Daytime/parking lights, Headlights, and Brights. So, when I pulled the two relays, that only shut off the main headlights and kept the daytime/running lights up front and all the tail lights illuminated (I also had the rear defrost, radio, and heater on) and the voltage at the battery maintained 14v. Once I put the relays back in the main headlights came back on, and the voltage at the battery began dropping below 14v. Greg Link to comment Share on other sites More sharing options...
idosubaru Posted December 2, 2021 Share Posted December 2, 2021 18 hours ago, suprunner said: Hey thanks for getting back! The JDM headlights have separate bulbs for Daytime/parking lights, Headlights, and Brights. So, when I pulled the two relays, that only shut off the main headlights and kept the daytime/running lights up front and all the tail lights illuminated (I also had the rear defrost, radio, and heater on) and the voltage at the battery maintained 14v. Once I put the relays back in the main headlights came back on, and the voltage at the battery began dropping below 14v. Greg With relays removed is it 14.0 or 14.5 or…? Test voltage with only one of those two relays installed at a time. Does voltage do same thing or different? The relay test suggests potential JDM light issues - wiring or otherwise. “Began dropping” - give us some numbers and time frame to understand what’s going on. How low does it go? When it’s dripping what happens if you increase RPMs? The alternator isn’t outputting much at idle Link to comment Share on other sites More sharing options...
lmdew Posted December 2, 2021 Share Posted December 2, 2021 You multimeter can lie to you unless you are checking voltage under load! LoadPro is the tool you need to add to your toolbox and use on your multimeter. Get a 9v battery, read voltage at the terminals. Now wet your finger, put it on one terminal and put the meter lead on your finger and read voltage. It will be very close to the same reading but you can't power the circuit through your finger. The meter will lie to you. LoadPro solves that issue. Search LoadPro Voltage Drop test on youtube. Link to comment Share on other sites More sharing options...
suprunner Posted December 3, 2021 Author Share Posted December 3, 2021 On 12/2/2021 at 4:18 AM, lmdew said: You multimeter can lie to you unless you are checking voltage under load! LoadPro is the tool you need to add to your toolbox and use on your multimeter. Get a 9v battery, read voltage at the terminals. Now wet your finger, put it on one terminal and put the meter lead on your finger and read voltage. It will be very close to the same reading but you can't power the circuit through your finger. The meter will lie to you. LoadPro solves that issue. Search LoadPro Voltage Drop test on youtube. On order. 1 Link to comment Share on other sites More sharing options...
suprunner Posted January 29, 2022 Author Share Posted January 29, 2022 Hi all, sorry for just letting this topic drift into nothing. I tracked down some bad light harnesses in the rear hatch and tail lights. I will be cleaning/replacing a bunch back there, and probably moving to LEDs to reduce global load as well. Thanks for all of your help! Greg 1 Link to comment Share on other sites More sharing options...
rverdoold Posted January 31, 2022 Share Posted January 31, 2022 With that topic title I was going to suggest to take the car to a drive-inn theatre and watch 'The exorcism' . Tail lights are prone for remaining moist, also check the rubber grommets on the housing. 1 Link to comment Share on other sites More sharing options...
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