joewildlife· Premium Member
Discussion Starter · #1 ·
So my 06 Sequoia with 187K had an intermittent whine coming from the engine that changed with engine speed. When it happened, it was coupled with low voltage on the gauge. So, in reading here and elsewhere, I was advised NOT to go with a remanufactured alternator. Problem is, the auto parts chain stores use cheap chinese parts to remanufacture the alternators, so they are not good as new. Folks said to go with a used alternator instead. I found a great deal for a 130 amp alternator from a junkyard Tundra with 132K on it. The Sequoia has a 150 amp alternator. My Tundra has a 130. They are interchangable. So I got the part shipped to me (for $45 to my door, no less!), and brought it to a Starter and Alternator shop and asked them to check the brushes and to make sure it is working. For nothing, they tested it and said it works great and had 90% of the brushes life left. So I felt good about installing it...it is kind of a bitch installing these things. Disconnect battery first. You have to remove the two bolts and one nut on the power steering, and detach the power steering reservoir. Then it is easiest to remove the large 12v wire and plug from the alternator through the wheelwell. Move the power steering pump forward (after releasing the tension on the serpentine belt), then remove the two bolts and one nut on the alternator and work it out from underneath. So I got the replacement installed and all is well again. Well, it threw MAP sensor code right after, so I cleaned the sensor and reinstalled, but the fault was probably just because the computer had to relearn everything after the battery was disconnected. I reset the code a couple times and now it is fine. BUT here is the take home point. The guy at the specialty shop had very good things to say about the Denso alternators. They last a long time. The weak point in them is the rectifier, and a failed or shorted rectifier makes that noise and results in the voltage loss. Also, ONLY use Denso parts to fix a Denso alternator. He told me that the aftermarket brushes are complete junk and they won't ever use them. I took my 150 amp bad alternator to them to rebuild, so I will have a spare on hand since I plan to drive the Tundra and Sequoia combined to 500K miles or more. If the Tundra alternator dies, I guess it will get an upgrade to a 150 amp! Oh, another take home point is to get an expert shop to rebuild your Denso alternator with Denso parts, never use a remanufactured alternator from a chain store for sure.