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Servicing a Denso

Have you ever come across a faulty Denso that drains your battery? Recently I’ve been trying to track down the source of my battery draw in my 142 and narrowed it down to the alternator. I replaced the rectifier bridge and threw in some new brushes but it didn’t fix my issue. I still see a 150 milliamp draw in a car with no extra accessories requiring constant 12v even though it still charges ~14v. I ended up just buying another alternator to try.
 
Have you ever come across a faulty Denso that drains your battery? Recently I?ve been trying to track down the source of my battery draw in my 142 and narrowed it down to the alternator. I replaced the rectifier bridge and threw in some new brushes but it didn?t fix my issue. I still see a 150 milliamp draw in a car with no extra accessories requiring constant 12v even though it still charges ~14v. I ended up just buying another alternator to try.

what feeds your excviter circuit?
 
Whatever fed the factory one I guess. When I swapped to the Denso I just used the original exciter wire in the harness and it worked fine until recently (I assume it would trace back to the cluster but I didn’t really dive into it since it worked). I only started to doubt the alternator when I was searching for the draw and couldn’t find it by pulling any of the fuses out. When I’d disconnect the battery cable from the alternator, the draw would drop back to like 1 milliamp.
 
Has anyone replaced the slip rings on one of these? I opened mine the other day to see if the diode/voltage thing is feasible and my (new) brushes are down to the wire. The commutator was slightly ridged but I didn't think it was that bad so I slapped it back together 3-4 months ago.
 
To 15A:

In your first post, you mentioned you purchased genuine Denso regulator, diode bridge and brush set for $75, may I ask where from since I need multiples of these parts

Thank you
 
To 15A:

In your first post, you mentioned you purchased genuine Denso regulator, diode bridge and brush set for $75, may I ask where from since I need multiples of these parts

Thank you

When I did it, I used the following ebay links. pretty sure they aren't genuine denso parts but they seemed to be well constructed and they have worked fine in my alternator.

https://www.ebay.com/itm/NEW-PREMIU...0-2-0L-2-2L-2000-09-021580-4850-/133260639200

https://www.ebay.com/itm/ALTERNATOR...HES-For-VOLVO-DENSO-740-940-2-3L/301222347380


super easy if you can find the parts locally or get these sellers to ship to you.
 
But are they any good? I’d prefer a good used one over most reman units, at least when it comes to a Bosch. Wonder if it’s the same story with the denso.

Along the same train of thought, ..I'm suspicious of so-called 're-built/re-manufactured' units from even reputable suppliers, and have so far been cannibalizing OE parts from my(Bosch) hoard collection that is running out.


;-)
 
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Regulator IN442 = 14.1 Voltage set point
Regulator IN443 = 14.4 Voltage set point
(Interesting to note that the Transpo IN443 says it has the LRC function but there was no provision for it on the unit I received. The joys of aftermarket strike again.)

Go for the IN443 if you want 14.5 volts running. The IN442 was only putting out 13.5 volts with a .5 volt drop over time in some cases.
The original Denso regulator part#: 126000-7160 (NLA as far as I can tell)
 
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Bumping because I got another bad Denso (with whisper quiet bearings) from a friend, swapped the parts I'd bought for mine over, and it works perfectly. I put the squeaky Bosch on the shelf where hopefully I'll never have to touch it again.
 
is it ok to just run the hot wire from the ignition right into the Denso alternator on a 240 conversion with nothing else in-line? I have a 100amp Denso on a 240 and it heats up with the ignition in the on position
 
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