Jump to content

Photo

Voltage Low When Headlights And/or Heater/ac Turned On With New Batter


  • Please log in to reply
21 replies to this topic

#16
GMS626

GMS626

    Newbie

  • Members
  • Pip
  • 14 posts
  • Car: 2000, Mazda 626, 2.0L 4cyl ,automatic

I honestly think the problem was with the original alternator.....14.05 V was too low and Autozone wouldn't have replaced it unless they thought so too! Now that you're at 14.5 (which is about where it should be) everything is better. As far as the heater drain I'm sure I have a TSB on that somewhere and will see if I can find it.



I did have some question why the first new one ran at 14.05V and the second new one ran at 14.50V But the serious drops and continuing depletion of charge did not go away until I cleaned the IAC.. The car acted the same with the second new one on every test until I cleaned the IAC. But thanks for the advice. Now I just have a problem with an over load because when you put alot of load on the charging system the belt starts squealing real loud. I turn off the heater and it goes away. Thanks!

#17
redsunn21

redsunn21

    Junior Member

  • Members
  • PipPip
  • 26 posts
  • Location: Florida
  • Car: 2002 Mazda 626 LX Auto I4
Tighten the alternator belt maybe? Mine had the same issue but I found out from a local Mazda mechanic if you don't use OEM Mazda belts they come loose easily.Two bolts to tighten it,very very easy job.

#18
GMS626

GMS626

    Newbie

  • Members
  • Pip
  • 14 posts
  • Car: 2000, Mazda 626, 2.0L 4cyl ,automatic
I took it for a test drive the other day and the water pump alternator belt broke, and it was squealing again. I had the heat and the low beams on. I baught a new one and did the tension according to the specs from the "Haynes" manual. Everything works good now, except that when alot of load is put on the alternator the belt starts squealing but the Volts stay up in the mid 14V. So I have decided that for now I can just drive the vehicle while keeping the load on the alternator down a bit. At least its major suffering is over because before I cleaned the IAC like Gilly said to do and make the new grounds I couldn't even drive the car. So thanks again guys for the help. Much appreciated! When I have more money I should be able to solve the remaining issues.

#19
MonoxideChild

MonoxideChild

    Veteran

  • Moderator
  • 6,590 posts
  • Location: RockFord,IL
  • Car: you name it, i own it...
belts dont squeal because of a load being placed on them. belts squeal because there old and degraded, or there too loose, too tight, or one of the bearings in one of the pulleys being bad.

#20
Gilly

Gilly

    Junior Member

  • Members
  • PipPip
  • 50 posts
  • Location: Tampa, FL.
  • Car: 1998 626 LX 2.0 Atx
Glad it worked for you. That's what were all here for.

#21
snailman153624

snailman153624

    Mazda 626.net

  • Admin
  • 15,693 posts
  • Location: IA
  • Car: '03 P5 MTX

belts dont squeal because of a load being placed on them. belts squeal because there old and degraded, or there too loose, too tight, or one of the bearings in one of the pulleys being bad.


A bad bearing induces an unusually high load [beyond the design value] on the belt, so it slips, producing the squealing sound. Friction is indeed a load.

Mono brings up a good point, though. Have you considered that perhaps it's not the alternator that's the problem? What if some other accessory on the same belt is causing the belt to slip, so the alternator stops spinning [or slows down]?

For example, on the V6 models [would have to check my 4 banger to be sure, as I rarely have needed to touch that car], the A/C compressor is on the same belt...if you turn defrost on, the A/C compressor runs [to dehumidify]...and if the a/c clutch is sucking down too much power, you will strain the alternator....or if the compressor bearings are bad, or the compressor vanes are jammed, and it will put a large load on the same belt as the alternator, and possibly slip around the crank pulley....

#22
GMS626

GMS626

    Newbie

  • Members
  • Pip
  • 14 posts
  • Car: 2000, Mazda 626, 2.0L 4cyl ,automatic


belts dont squeal because of a load being placed on them. belts squeal because there old and degraded, or there too loose, too tight, or one of the bearings in one of the pulleys being bad.


A bad bearing induces an unusually high load [beyond the design value] on the belt, so it slips, producing the squealing sound. Friction is indeed a load.

Mono brings up a good point, though. Have you considered that perhaps it's not the alternator that's the problem? What if some other accessory on the same belt is causing the belt to slip, so the alternator stops spinning [or slows down]?

For example, on the V6 models [would have to check my 4 banger to be sure, as I rarely have needed to touch that car], the A/C compressor is on the same belt...if you turn defrost on, the A/C compressor runs [to dehumidify]...and if the a/c clutch is sucking down too much power, you will strain the alternator....or if the compressor bearings are bad, or the compressor vanes are jammed, and it will put a large load on the same belt as the alternator, and possibly slip around the crank pulley....


Good points! The only two items on the smaller belt are the water pump and alternator. Alternator is brand new and the water pump was removed and inspected and was found to have zero faults. I had baught a new water pump when I went to do the alternator but when I removed the old one I physically inspected it and compared its movements to the new one out of the box and there was absolutley no reason to replace it. The shafts spins freely and without restrictions. There also was no play or any hint of any malfunction in the shaft. I could not bring myself to replace a perfectly good part.. That water pump probably has alot more miles on it. It pretty much seems new all around.The other larger belt has the Power Steering Pump and A/C compressor. I baught the belt to bypass the A/C crompressor since it is broken anywho. So that one is just the Power Steering Pump. My origianl thought was it was the A/C compressor but the bypass belt had no fix for the squeal. So that is why I am leaning towards the overload on the Alternator because everything is 100%. And if the Power Steering Pump is slowing down why is it doing it when the car is in Park? So however I did start the motor with the Power Steering belt off and just the Alternator and Water Pump and that is how I came to that theory because it was squeaking. The same squeak. Unless there are two identical ones. Thanks again for the replys. I got to drive the car today to and from college. With the lights on and the heater on "1". But it was nice to drive it again. And it was on the freeway! Thanks!




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users