I recently changed the drive belts and ever since, voltage sits at mid 11 volts at the battery and alternator when the vehicle is running. It was always mid 13s to 14 volts prior to the belt change. OEM belts and nothing else done during the service. Any ideas? It doesn’t make sense and not sure where to look.
Changed belts and now no charge from alternator (1 Viewer)
- Thread starter Blilrat
- Start date
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CharlieS
GOLD Star
Did you use a belt tension gauge to set the correct belt tension?
I have a cheap Krikit gauge that works well enough, under $20 when I bought it.
Seems they've gone up in price: Amazon.com: Gates 91107 Krikit V-Belt Tension Gauge, Black : Automotive - https://a.co/d/amjvAIG
I have a cheap Krikit gauge that works well enough, under $20 when I bought it.
Seems they've gone up in price: Amazon.com: Gates 91107 Krikit V-Belt Tension Gauge, Black : Automotive - https://a.co/d/amjvAIG
COS80
SILVER Star
Check that you didn't bump/forget to reconnect any wiring.
- Thread starter
- #5
Belts were the correct tension using the gauge and still low voltage and battery is not charging. I went ahead and pulled the alternator, check the brushes nd all wiring. Brushes were within spec, but changed them anyway since I had new ones sitting around. After putting it back together and running it for a minute or so, I noticed the alternator is scorching hot. I was thinking regulator, but I thought the symptom of a bad was high voltage, not low. Battery is less than two years old. Is this a sign of a bad alternator?
Malleus
Far west of Siegen
Heat is the result of too much current being shunted to ground. The regulator controls the output of the alternator; the generator just spins.
I'd be the failure is coincedental. There are function checks in the service manual for the alternator.
The rgualtor cannot be "rebuilt"; at leat not easily and not unless you're a) a glutton for punishment, or b) just really into science projects. Unfortunately, a new regulator is almost the same cost as a new alternator, so if it was me, I'd just replace the whole thing.
I'd be the failure is coincedental. There are function checks in the service manual for the alternator.
The rgualtor cannot be "rebuilt"; at leat not easily and not unless you're a) a glutton for punishment, or b) just really into science projects. Unfortunately, a new regulator is almost the same cost as a new alternator, so if it was me, I'd just replace the whole thing.
"---unless you're a glutton for punishment"
I'm a glutton (but not an expert) and yes it was a pain in the arse rebuilding an alternator. I did it more as a learning experience but it was a lot of work; taking the case apart, pulling the bearings off the rotor shaft, cleaning off 25 years of oil and grime, sanding the slip ring, re-coating the rotor and windings with the correct insulating varnish (found micro-cracks had develop on the wiring from age/oil exposure), new brush pack, bearings, ---- .
You can get really deep into it (replacing the slip ring if worn for example) but can save money by shopping around for aftermarket parts as the OEM parts cost more than a Toyota Remanufactured unit. Downside is that most of the (affordable) aftermarket parts will be made in Chy nuh or (maybe better, Korea). IME the Rectifier is something that seems to pop (bad diodes) before the voltage regulator goes bad but while it's all apart might as well replace it also.
If all someone wanted to do is replace noisy bearings and a brush pack for example that wouldn't be too bad but once it's apart you'll end up wanting to replace/repair everything else so better (less painful) to just buy a new OEM Reman unit while they're still available.
If I ever find my rebuild photos I'll post them up.
For future searches FWIW:
alternatorbrush.com
www.dbelectrical.com
I'm a glutton (but not an expert) and yes it was a pain in the arse rebuilding an alternator. I did it more as a learning experience but it was a lot of work; taking the case apart, pulling the bearings off the rotor shaft, cleaning off 25 years of oil and grime, sanding the slip ring, re-coating the rotor and windings with the correct insulating varnish (found micro-cracks had develop on the wiring from age/oil exposure), new brush pack, bearings, ---- .
You can get really deep into it (replacing the slip ring if worn for example) but can save money by shopping around for aftermarket parts as the OEM parts cost more than a Toyota Remanufactured unit. Downside is that most of the (affordable) aftermarket parts will be made in Chy nuh or (maybe better, Korea). IME the Rectifier is something that seems to pop (bad diodes) before the voltage regulator goes bad but while it's all apart might as well replace it also.
If all someone wanted to do is replace noisy bearings and a brush pack for example that wouldn't be too bad but once it's apart you'll end up wanting to replace/repair everything else so better (less painful) to just buy a new OEM Reman unit while they're still available.
If I ever find my rebuild photos I'll post them up.
For future searches FWIW:
Search: 4 results found for "27700-75020"
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Rectifier for Denso 021580-3660, 021580-3830, Toyota 27357-16310 172-52002
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