Announcement

Collapse
No announcement yet.

Alternator/Battery trouble.............

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

    Alternator/Battery trouble.............

    Here's the deal. My car is a 92 MT2 app, with 148k, auto, vert, power top in-op. DD right now 80 total miles per day. No special electronics. Alpine 126bt hu, with Alpine 5.25 on all 4 corners. Recently had a notice of loss of power and idle drop from 750 to 500. 2 weeks ago car sat for 8 hours. got in no start. That dreaded click,click,click. Dead battery. 2 year old Interstate. Got a jump. Zoom. Got a battery from a friend. (Thanks Peter Brown). One of those old school, white casing, original BMW batteries with the green "Im good" window. Charged that battery 24 hours. Put it in the car. Zoom. Put the Interstate on charge. While driving on the bmw original my anti lock light comes on. Oh shit alternator ????? Later that day. Got in the car. Nothing. no horn, no interior lights, no crank. zero. Jump start. Zoom.

    Ok. Time to get the alternator checked. Took the car to an auto electric specialty shop. Bad diodes in the alterantor. Ok. Purchased a Bosch re-man. Thanks Rennie @ Redline. Still on the bmw original battery but tnought I would take the Interstate in for a look see. Advanced Auto battery check. Only place open that late. Your Interstate is trash. 2 years, Florida weather. Ok, Im good. Give me one of your Silver whatevers. Ok. Got home installed the alternator. New battery. Re built aternator. Im good. Got my meter out. Battery good. Start her up. Zoom. Im good. you know what happened. one week later. Nothing zero no ping no ding no daddy I love you nothing. She was lights out. Got a jump. Zoom. Back to advanced. Second battery. New New New battery. I want one off the truck. Zoom.

    Checked for power draw. Nothing. Tell you what I did notice. Corrision on the positive battery lead. I just cleaned that off 2 weeks ago. WTF. not a lot but a little powder. Changed the positive connector. Here's another kicker. My ac was blowing tits every fresh battery. Like brand new. 134 conversion a year ago. And on a cold start, she doesnt hold idle. I mean no idle on a new icv. my idle is now 500 down to 300. Smoke test, thanks Peter @ Road and Race, pretty good size intake leak in the vcg. Ok I'll get new vcg and silicone. First thing i want to do is fix the charging issue. The gasket is easy. New battery, get her hot, and she stumbles up to 500 and holds steady. Not that one has anything to do with the other, just food for thought. I have never changed my TPS and the current one is not clicking. So I have ordered a new one. But damn.........................

    Alright. Thats my story. Any help would be appreciated.

    P.S. Thanks Jim Levie. Your're the best..............................G.

    #2
    Was the replacment alternator actually a Bosch factory reman unit? Or a generic rebuilt? Once clue could be the cost of the replacement with a factory reman running about $240. My experience with the generic rebuilts has been poor and sometimes it means swapping in three or more to get a good one. Now I only use those rebuilt by Bosch.

    It is easy enough to tell if the alternator is working With the battery fully charged, check the system voltage at idle (should be at least 13.5v) and at 2500rpm (should be right about 14v). Those voltages should not drop much at all if you load the system by turning the headlights on hi-beam and turn the HVAC blower to max.
    The car makes it possible, but the driver makes it happen.
    Jim Levie, Huntsville, AL

    Comment


      #3
      I'll check with Rennie and see if the reman was Bosch factory. What would be a good digital volt meter to buy? The one I currently have is 10 years old. Any suggestions? Whats your take on the idle issue. Should I tackle the intake leak first or the charging issue?

      Comment


        #4
        If your 10 year old meter still works, it is probably fine for this test. I personally prefer Fluke DMM's but there are lots that are cheaper and are more than adequate. You might as well work both the idle and charging issue at the same time.
        The car makes it possible, but the driver makes it happen.
        Jim Levie, Huntsville, AL

        Comment


          #5
          Mr. Levie please post your choice of silicone and procedure for the vcg and your opinion on the charging issue. The vcg leak is right above the oil return tube and under the triangular bracket that holds the intake manifold to the vcg. The charging issue is as written. For some reason I am thinking the low idle may be affecting the ac and charging system. No enough turns of the belts. Is that possible?

          Thank you sir.

          Comment


            #6
            I don't use any sealant on the valve cover gasket, but every time I change the gasket I also change the four rubber bungs. The only place on an M20 engine that I regualry use sealant is on the water pump gasket and the oil pan if I'm installing a crank scraper.

            A leak around the top of the oil return tube is either a bad seal for the return tube or bad intake manifold gaskets.
            The car makes it possible, but the driver makes it happen.
            Jim Levie, Huntsville, AL

            Comment


              #7
              What do you think of the low idle affecting alternator efficiency. Any possiblities that could be the case? Are there any other issues that would cause the alternator not to charge the battery? Or not to deliver power to the cars charging system. I understand battery failure could be that the car is running on the battery and not the alternator. And that it may take a week or 2 before the battery just drops to 0 starting capacity.

              Thanks again.

              Comment


                #8
                A lower than normal idle will reduce alternator output when the engine is at idle. But that won't affect alternator operation when the car is being driven as the engine speed is always much higher.
                The car makes it possible, but the driver makes it happen.
                Jim Levie, Huntsville, AL

                Comment


                  #9
                  Yes, but when the engine is at idle, a low idle would defer to the battery for power. Making the battery weaker everytime the car idles below 500. = shorter battery life. Possible???? 1 used battery and 1 new battery within 3 weeks. FYI, the alternator is a Bosch reman. So I will wait a couple of days and check the battery for voltage to see if it has gotten any lower. And check the alternator unload and load. I was just thinking that there must be a reason that the alternator is not sending charge to the battery. Bad wire, bad relay, bad ??????? Any suggestions?????

                  Comment


                    #10
                    Run the system voltage tests I described earlier. Those will tell if the alternator is working properly.
                    The car makes it possible, but the driver makes it happen.
                    Jim Levie, Huntsville, AL

                    Comment


                      #11
                      Per your direction, the system voltage test were run. They all came out normal. However the alternator check did show what was described as a "ripple". Never heard the term. What does "ripple'" mean? The young guy who did the test was not able to give me enough information to make sense to me. Any ideas?

                      Comment


                        #12
                        Excessive ripple in the alternator output is from bad diodes in the alternator.
                        The car makes it possible, but the driver makes it happen.
                        Jim Levie, Huntsville, AL

                        Comment

                        Working...
                        X