alternator issue after fanbelt replacement, Fanbelt replaced |
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alternator issue after fanbelt replacement, Fanbelt replaced |
jrblackbox |
Oct 23 2018, 05:01 PM
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#1
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Member Group: Members Posts: 285 Joined: 8-September 15 From: Easton, CT Member No.: 19,140 Region Association: None |
My fan belt was quite loose, so i replaced it, tightened the new belt up to about a 1/2" of play. After about 10 minutes of driving the alternator red light popped on, the tach, signals, and gas gauge all stopped working. Stopped the car thinking the belt had fallen off but it is still on with the same tension. Why should I have an issue with the alt after just changing the belt?
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VaccaRabite |
Oct 23 2018, 06:20 PM
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#2
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
Turn on the car and find out if the belt is moving.
make sure the alternator is spinning. See if the alternator is charging using a voltmeter. There are lots of possibilities here - I just went thouh this. You have to start crossing things off the list. Zach |
Spoke |
Oct 23 2018, 09:59 PM
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#3
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Jerry Group: Members Posts: 6,992 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
It sounds like a fuse blew. The gauges should not stop working if the alternator is not working.
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jrblackbox |
Oct 24 2018, 03:06 PM
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#4
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Member Group: Members Posts: 285 Joined: 8-September 15 From: Easton, CT Member No.: 19,140 Region Association: None |
Thanks for the responses. The alternator is spinning, the belt is still on. Will now check fuses, but why would the alternator light go on for a blown fuse? Upon starting the car neither the green oil or red alt light were lit. once started the red alt light came on.
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Dave_Darling |
Oct 24 2018, 03:23 PM
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#5
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914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
I think it's fuse #8 that has popped. A few other things won't work either, you'll find. Turn signals, possibly some other lights...
Find the short and fix it. --DD |
jrblackbox |
Oct 24 2018, 03:57 PM
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#6
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Member Group: Members Posts: 285 Joined: 8-September 15 From: Easton, CT Member No.: 19,140 Region Association: None |
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Dave_Darling |
Oct 24 2018, 05:16 PM
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#7
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914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
Tach drops to zero, alt light comes on, some other stuff doesn't work? They're all powered by fuse #8. (The alt light is sort of powered by that fuse, it's a bit complicated.)
Mine used to short one of the connectors on the back of the fuse to the bracket holding the fuse box. I was missing one of the screws that held it in, and sometimes the whole thing would shift just far enough to short. POP! There goes the tach and other stuff. I think the short in the license plate lights also popped that one? A body shop wired up the lights backwards, and the power lead was shorting to the metal body of the bumper... That was a fun one to track down... --DD |
Spoke |
Oct 24 2018, 05:35 PM
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#8
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Jerry Group: Members Posts: 6,992 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None |
...Upon starting the car neither the green oil or red alt light were lit. once started the red alt light came on. It is likely the secondary voltage from the alternator was trying to drive the components on the blown fuse circuit which is why it came on when the engine was running. |
76-914 |
Oct 24 2018, 05:36 PM
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#9
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,512 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California |
Tach drops to zero, alt light comes on, some other stuff doesn't work? They're all powered by fuse #8. (The alt light is sort of powered by that fuse, it's a bit complicated.) Mine used to short one of the connectors on the back of the fuse to the bracket holding the fuse box. I was missing one of the screws that held it in, and sometimes the whole thing would shift just far enough to short. POP! There goes the tach and other stuff. I think the short in the license plate lights also popped that one? A body shop wired up the lights backwards, and the power lead was shorting to the metal body of the bumper... That was a fun one to track down... --DD (IMG:style_emoticons/default/agree.gif) with the license plate lights. Had that happen once. IIRC, isn't the coil on that circuit also? Maybe it has shifted? (IMG:style_emoticons/default/beerchug.gif) (IMG:style_emoticons/default/beerchug.gif) |
jrblackbox |
Oct 24 2018, 06:36 PM
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#10
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Member Group: Members Posts: 285 Joined: 8-September 15 From: Easton, CT Member No.: 19,140 Region Association: None |
Is this just a coincidence happening now, after replacing the fan belt? Or could I have hit/moved something on that relay board while adjusting the belt?
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Dave_Darling |
Oct 24 2018, 09:43 PM
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#11
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914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
Unlikely, but not impossible. Worth checking anything you could have bumped in the area...
--DD |
jrblackbox |
Nov 3 2018, 03:46 PM
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#12
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Member Group: Members Posts: 285 Joined: 8-September 15 From: Easton, CT Member No.: 19,140 Region Association: None |
Found the short, it was the lighter! Back on the road. Thanks for the help.
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