I am brand-spanking new to this humble board! I am coming over to you based upon the recommendation of several from the fine folks at the Nasty Z28 2nd Gen board. I have been a regular invisible viewer since about June when I sold my 79 Z28 and bought my current car, a 1987 Iroc, all factory 305, AT, you know the rest. Up until now, my car has been a daily driver, and given me much good fortune! Here is where my questions begin...battery died about 4 months ago, brought it in and had it checked, it was stone dead. Bought new high-dollar battery, everything ship-shape and running strong. Then, just the other day, it gives me this sound like the battery is low again...ok, so I throw it on the charger for good measure...next morning does the same thing, starter sounds growly and weak. Following day, symptoms progressively worse, despite showing full charge at guage and with external battery charger, lights are on full bright, all guages work, etc, etc. One more trip to the store, and she was stone dead. No power to the starter, or so it would seem. Turn the key and not even a click from the selenoid. But still full power to everything else. Hmmm...so I went to the store and purchased the obligatory new starter, installed it (no small feat, considering the amount of wiggling and twisting required to get it into its little spot!), but still no go!!! AAARGGGG! So I have now checked all of the fuses that I can find, all of the fuseable links, and I still come up with nothing. Tried to start it in NEUTRAL, to see if the safety switch might be bad, but that made no difference. I can hear the fuel pump charge up, but nothing happens when I hit the key.....I am looking for any and all suggestions, tips, comments, and accolades! I have yet to replace battery cables, and am suspecting either the cables or the ECM module. But I am not sure of the location of the ECM, and if it would give me the "dying battery" symptoms just out of the blue. PLEASE give me your thoughts!!!!! Thanks, Eric

 

ECM is under the dash on the passenger side (right next to the sidewall), you should have to remove 1 piece of plastic to get at it. The one right above the passenger's feet., Sorry not enough experience with 3rd gen's yet to answer the other Q's... however I would recommend you do a search on this site for your questions (would've answered the ECM location question) and maybe others.

 

First of all welcome. The ECM should be a last resort. The best way to troubleshoot this is with a helper and a voltmeter. You will have to measure the voltage at the starter solenoid when you try to crank it. If you get it to run check alt output at the battery with a voltmeter, it should average around 13.5-14 volts. Will it start with a jump-start? If the charging system is OK then maybe you have something drawing current enough to drain the battery. If it kicks right off with a jump that may rule out cables and/or connections. Just take a logical approach starting with the battery and work from there. If you don't have a multimeter, get one or just take it to a place and have it tested. If you own a TG, a meter is a tool as important as any set of wrenches. Keep us posted, Dan

 

I have done tons of searching thru past topics, and am not finding anything exactly what I am looking for. No, jumping it does not help. Charging the battery with an external charger doesnt help. Volt-meter at battery shows strong 12 volts. I just had alternator checked a few months ago when replacing battery, and checked out perfect. A reply to this same post on the other Z28 board suspects one of the three wires that go to the selenoid--a fuseable link. Would this give me a "dying battery" symptom??? I know that a long time ago I had a 77 Caprice that had one of those wires work loose and caused all sorts of funky things to go on with the lights and electrical system. That will be the first place I look tonite when I start the investigation. If I do end up looking to replace the ECM module, how much $$$ am I looking at?

 

Just FYI, i don't think the ECM has anything to do with the starting system, which i belive is what your haveing trouble with. No rotation, right? If so, check all your wires and such. Over all its a pretty simple system, with one wire (usally the thickest red wire) going to the starter from the battery. The Starter would then be grounded to the block, which in turn is grounded to the battery through another wire. The smaller red wires going to the starter come from the ignition switch, which would give power to the starter solinoid.

My question is, do the lights dim when you try to turn it over, do they stay on perfectly bright, or do they just go out? I had one car that had a bad ground connection where it would lose its connection when starting and just kill all power to the inside of the car. After shaking the connection to the battery it would come back on and the car would turn over.

It would probably be a good idea to check the wires for good contiunity and making sure they have a connnection. After that, i would get a remote starter (or a length of wire), and basically 'hot wire" the starter to see if that would get the starter to turn over. If you don't know how to do this, you just need to get a length of wire from the solinoid lead to the postive terminal of the battery. If the starter kicks in, you might be able to limit the failure to the switch. If the starter doesn't turn over, there is probably something wrong with the starter. I know its new, but anyone can tell you, you might have gotten a bad starter. Its not the strangest thing to happen in the world.

Well, there are some ideas. Good luck.

Joker

 

Thanks Joker37, I was thinking along a similar vein...and you are correct, no rotation of the starter at all. Power to rest of car...hmmmm, cant recall for sure what happens when I key the starter. I will check continuity of all wiring to starter, and try the hot-wire method also. Thanks for your input. And I hear you on the "new" starter

 

My Opinion:
I had the EXACT problem.
Its not the wiring or a relay or a switch. Its not a sandwhich stuck between the flexplate and the torque converter. its not a fried lizard on the back of your coil. Nope.

Its your starter. Dont replace it with a remanufactured OEM starter either, get a high torque mini-starter (a cheap one~ $100-150) and throw a heat shield on it. Problem solved.

 

Could this be as simple as a battery that has died after only 5 months of service?????? I have tested and retested all my wiring, and coming up with nothing. Checked codes on ECM, got nothing, only standard 12, 12, 12. And so after making sure everything was tight and installed correctly, I ran a test to hotwire the starter........and got nothing. Battery reads 11 volts, wont even kick the selenoid......small spark when I jump it, but the "NEW" battery is supposed to be pushing 850 amps!! This would explain the progressive 2-day symptoms described early on. I will take it even for a check tomorrow (24 month free replacement warranty ). Hopefully, this will be it...........

 

Erick, crawl under your car and beat on that starter with a hammer while someone cranks the ignition. If it starts then take the starter back where you bought it. if it doesn;t

Disconnect the battery .. Both sides. Measure the voltage avross the terminals.. Is it 12 volts now and with the terminals hooked up they only show to be 11 ? Bad connection to terminals. Max voltage loss at a battery terminal is only .5 volts when cranking .. 1 volt is too much just setting fix connections or clean cables..... fix it ?

If it still doesn't start then use a test light to see if the single purple wire to the solinoid (s terminal) lights up when the ignitions cranked. if it does have power there then replace the starter again.

Only posible options are Defective Starter = Probobal
Bad battery/cables/connections = maybe connections
Neutral safty switch and or wiring
Ignition switch and or wiring
alternator

I've changed so many defective starters in my life It's pathetic

It's for sure not ECM related and the car doesn't have vats so that leaves those two things out period.

 

Excellent advice, 90Formula-X-F. I am cruising the archives right now, researching battery troubles. I have ruled it down to the 1)battery, 2) cables, 3)defective starter....based on symptoms. (and not ruling out safety switch). I will keep diagnosing, should have it figured out by tomorrow. Thanks to everyone for your great input, I will keep this post updated for the benefit of all.

 

Well folks, here's the story.....Took "NEW" battery down and had it tested, it was only putting out 150 amps. Got replacement for free. Put it in. Stil nothing . More checks. after remembering to keep it simple, checked all the connections.............and..............wait for it......................I put the purple wire on the wrong stud.............the new starter has two small studs, and I reinstalled it on the wrong one. Switched to other stud. IT BREATHES!!! IT LIVES!!! Lesson #1: Check all "NEW" parts, and suspect them until you die. Lesson #2: Someone somewhere said this...the starter that you get may have the extra small nut installed on the WRONG stud, so check and doublecheck correct wire placement if your starter has 3 studs (1 large and 2 small) instead of 2 (1 large and 1 small). So original problem was my ace #1 battery, although upon removal, it was obvious that my starter was near its end as well. That being said, I express my gratitude to all of you for your input, it really did help.!! Peace Out :rockon: