Alternator advice

Well I posted about a dead heater blower (http://www.automotiveforums.com/vbulletin/showthread.php?t=887742)and got little response/help but I believe I may need an alternator.:sly:
I see many for sale on the web some Bosch, some Denso and some USA INDUSTRIES . (http://www.autopartswarehouse.com/search/?D=acura+alternator&Ntt=acura+alternator&Dx=mode+matchallpartial&Ntk=Main&Ntx=mode+matchallpartial&N=4294967271+9503&Nty=1&V=1562+4294967271&Vh=1998%20Acura)
Some are 70 amp some are greater. I am hesitant of purchasing a 70 Amp. I understand many believe I need to buy an OEM ALT but those cost big bucks, that I really don't want to spend if I do not need to.
If I buy a Denso (nipondenso) am I buying OEM? Or which ALT should I get and at what Amperage?
Oh this is for an 1998 Acura SLX.
Is this place still alive?

DMikeM,

Do yourself a favor and look for a local automotive electric rebuilder. The denso alternator used by Isuzu is not that complicated a unit. I took the one off my 96 Trooper to check the brushes and bearings, which were in great shape at 120,000 miles. A rebuilder will test all the componets of your alternator and replace excactly what it needs. Plus you know what you have because it is your original unit. It may take a couple of days to get it back, but I can guarantee you will be alot happier.

Copter Steve

To late, I checked with the local guy and he would have been over a week so i ordered a new Alt from Napa Auto parts.
I may just keep my core and take it to the local guy and have it fixed up then switch back and use the Napa as a backup.

Well after paying for someone to install the Napa Alt we found it defective. Now I am driving around with a new Bad alt installed while the local guy is rebuilding my original alt. :banghead:

DMikeM,

Very interesting. I wonder what is wrong with the NAPA unit? Did the local rebuilder test your OE unit to see if it is working? Are you still having the same issue with your blower motor? I will be looking forward to your post when you get your OE unit back.

I use to work for Napa as a outside salesman, I also owned and operated my own electrical rebuild shop and after I got my Airframe and Powerplant license I ran a aircraft accessory rebuild shop. Presently I work in a overhaul shop for probably the premier heavy lift helicopter outfit in the world. So saying that I always find these types of challenges very interesting.

Copter Steve

The Autoshop that installed the Napa ALT tells me it is only putting out a few amps (under 10). It is putting out 14.4 V at the ALT but as soon as you put it in the system it drops to about 12.4 barely enough to keep the battery charged.
The heater blower is still not functional. Does anyone know where the charging relay might be?
The local rebuild guy is a nice older man that works out of his garage. I am headed his way in 30 minutes to drop off the OE ALT for the rebuild. It may be fine and not need any work at all.

This crap sux!
Got OE alt rebuilt, had it installed. Battery light and brake light now are on constantly and the heater blower still does not function. But I am getting 14.4+ volts at the battery.
Thinking of just ordering a new alt from Denso.
http://www.densoproducts.com/more_info.asp?AAIA=1315883&pid=16923

Or this one.
http://www.maniacelectricmotors.com/alacslxistr.html

G'day DMikeM,

your trials sound similar to some I had not long ago. Rebuilt original alt was charging Ok but playing havoc with the dash lights http://forum.planetisuzoo.com/viewtopic.php?t=13757

It was a faulty internal regulator in the alt. I had to buy a replacement alt.

It probably is the regulator. As my rebuilder was explaining how difficult it was for him to find the correct one. I bet he choose the incorrect one.

I'm looking at the wiring diagram ... the alternator does trigger the AC/heater relay after passing through the starter relay. Interesting. The AC/heater relay supplies power to your 25 amp blower motor fuse and the 10 amp AC fuse. Hard to believe that all the alternators would have this same problem. Could be either relay. Rather than checking power to the switch and the blower motor, check power to the fuses. If none see if you are getting 12 volts from the white-green wire from your alternator. This is the wire that passes through the starter relay and triggers the AC/heater relay. The reason it passes thru the starter relay is to turn it off when you are cranking the vehicle.

You could also jumper 12 volts to that wire and see if you get power to the ac & blower fuses.

as far as your alternator goes ... that sucks. I can tell you from experience in my shop, NAPA alternators have a high failure rate right outta the box. All those rebuilding companies have high failure rates really, we just deal with NAPA more than any others.

I'm looking at the wiring diagram ... the alternator does trigger the AC/heater relay after passing through the starter relay. Interesting. The AC/heater relay supplies power to your 25 amp blower motor fuse and the 10 amp AC fuse. Hard to believe that all the alternators would have this same problem. Could be either relay. Rather than checking power to the switch and the blower motor, check power to the fuses. If none see if you are getting 12 volts from the white-green wire from your alternator. This is the wire that passes through the starter relay and triggers the AC/heater relay. The reason it passes thru the starter relay is to turn it off when you are cranking the vehicle.

You could also jumper 12 volts to that wire and see if you get power to the ac & blower fuses.

We had checked the circuit on both sides of the fuse box and it was dead (no power) I have replaced the relay already and even switched them around as they are all the same in there and it made no difference. I have read somewhere that someone actually cut the green/white wire and everything started working. I have yet to locate the blower resistor and check it out. That is something planned for this weekend. Working till almost dark and it being in the 30's after dark puts a hamper on auto repair.

What Diagram are you looking at, is it from the Manuals posted on RapidShare? If so can you tell me the page number?

Thanks for the replies BTW I was beginning to think there was no help to be found here.

don't even bother with the resistor if the circuit has no power, ya know?

I get my wiring diagrams from AllData. The program won't allow cutting and pasting or I'd send you a copy.

I don't see how everything could work if you cut the white/green wire. It supplies the power to trigger the relay. Without it the relay won't switch.

Ok Update I got the heater working. After installing the newest Alternator Rebuild and finding all my warning lights are correct but still no heater blower I removed the glove box and took out the heater resistor. Pinch the lock tabs closed and found it was busted cold solder joints and 2 terminal tabs had separated. Resoldered the tabs, reassemble and reinstall and I have heat and AC! I think I had a semi for a few minutes after.

Here is a pic of the trouble part. They did a terrible job soldering.
There is a higher res shot in my folder (in my Sig) if you need.

http://webpages.charter.net/revenge/pics/SLX/brokerstr.JPG

ALT Update and help requested.
The newest rebuild has made all the warning lights go away and the car runs fine but it is only showing 12.7 volts at the battery but 14.7 at the connection to the harness. Is this correct?
I turned on everything including seat heaters, high beams, mirror heaters wipers radio and hearter blower ( yippie) and the voltage stays at 12.5 even if I rev up the motor.

My next step is to contact Denso and ask them about there ALT's.

if the battery is fully charged and good, that's no good.

Normally I test an alternator with amps, but it should be at least 13.5 volts at the battery. If the problem is not the battery, you might need to test amperage output of the alternator.

if the battery is fully charged and good, that's no good.

Normally I test an alternator with amps, but it should be at least 13.5 volts at the battery. If the problem is not the battery, you might need to test amperage output of the alternator.

Is there a way to test AMPS with a digital multi meter?. I am wondering if the AMPS are low because this is the same results I had from the Napa Auto Parts Alt I returned because the Auto Repair Shop stated it was butting out 14.5 volts but not enough AMPS.

Everybody tests differently. I used an amp clamp around the negative cable, then I load the battery with a carbon pyle battery tester. That will force the alternator to go to max output.

A good amp clamp is like $300 and they don't usually come with a multimeter. The amp setting on a multimeter is usually only 20 amps max.

Weird that you have 14.5 at the alternator and 12.5 at the battery?!? Maybe try disconnecting circuits and see if it changes? I can't imagine what would have that kind of a voltage drop?

Everybody tests differently. I used an amp clamp around the negative cable, then I load the battery with a carbon pyle battery tester. That will force the alternator to go to max output.

A good amp clamp is like $300 and they don't usually come with a multimeter. The amp setting on a multimeter is usually only 20 amps max.

Weird that you have 14.5 at the alternator and 12.5 at the battery?!? Maybe try disconnecting circuits and see if it changes? I can't imagine what would have that kind of a voltage drop?
I could try the old small battery that used to be in there. I replaced it with a big deep cell type.
When you disconnect the main harness plug near the battery (fuse relay box) and check the volts there it is over 14.5. I will see if my shop at work has an amp clamp. We have a pretty good sized vehicle maintenance shop, and the electrical department might have something.

Had an amp clamp test done and found the ALT is putting out from 45 to 70 AMPS before the battery connection and 14.5v before the battery.
Almost no AMPS at the battery cable and 12.7V at the battery. This is all under full load. Everything electrical turned on.
Today I sent an email to Denso Aftermarket tech support to ask if this was normal behavior. Waiting for a reply.

I had the same problem and it turns out that all the local parts house sell the 75 amp alternator. I called Isuzu with my vin and they told me I needed a 90 amp alternator (which no one here sold). Parts house had already disposed of my 90 amp alternator so I bough a used one for 35 bucks and am now on my 3rd year with it. I was told they electrical system shuts down non essential systems to get the right amount of power to more critical applications. As soon as I got the 90 amp alternator everything started working again. Hope this helps