I have an 89 Rs with a 305 Tbi. I recently switched out the motor and been having trouble with the charging system. Originally, I just put in a new starter before i switched engines, thinking the locked up old motor just had a bad starter: Nope. So i switched the engine, connected everything, then started driving. Two days into driving it in 39 degree weather; the car didnt start. I could hear the starter clicking, and with a jump it would start. I switched out the battery, twice. When i drove it i noticed the voltage gauge slowly decrease. So i switched the alternator, thinking, new starter, new battery, new alternator. But im still having the same problem. Now I'm thinking a bad ground wire. What should I look at? Which fuses might be causing this problem?

 

I know it's new, but have the alt and battery both tested (free at most auto parts stores). I replaced my alternator and come to find it was bad out of the box.

Grounds should be
1) neg bat cable to block
2) block to firewall
3) fender to neg batt terminal

 

Not sure if it'd help but also check the battery cables too.

 

Thanks for the quick replies. I disconnected the negative battery cable from the block, cleaned it, and cleaned the terminal post, same outcome. I'm going to check the block to firewall grounds. The alternator should recieve small voltage with the key on the on position, correct? If i can charge the battery enough, maybe I can head to the autoparts store I purchased the alternator from to check it. Which fuses should I check, if any?

 

I charged the battery, started it up. And while it was running I disconnected the battery, it died immediately.

 

if it died right after you pulled the cable, then the alt's not putting out any juice to the battery. check to make sure the wiring from the bat positive to the alts ok and that you don't have any bad connections to the alt plug

be careful if you're pulling the battery cable on a car with an ecm/pcm/etc; it can cause a sudden spike and cause more issue

 

i agree, have the alt double checked just to be safe. i just rebuilt my 305 in my 89 camaro, after putting in the engine everything was charging fine. then out of no where my battery died on me on the side of the road in the middle of the night. turned out my alt went bad on me. in the mean time go over all the wires. make sure all the grounds are connected and there are no frays in it. also make sure the wire coming from the alt isnt hooked directly to the battery, it has to go through an alternate routing or will over charge your battery and kill the cells in your battery. before the whole rebuilding process i had the same problem. and went through 3 batteries before i figured out what the problem was. so double check the wires, make sure everything is tightened down, and there are no cracks or frays on the wires that could cause them to touch anything else. hope this helps

 

I had the same problem. On my car it was a direct wire from the back of the altinator to the battery it ran in front of my radiator and my wire was snapped clean in two. Ran a new wire and didn't have another problem since.

 

Check the "C-H fan fuse"! or you have a wiring problem

 

I checked the wires, changed the alternator, and drove it home from the shop. Turned it on and off and it was ok. This morning I turned it on, and the battery didnt have enough juice. This is really starting to get old. C-H Fan Fuse?.. I'll check that out. Also, I dont have the fan switch that goes on the block, what can I do to get around this. The block has a square type bit plug, that is a bitch to take off. Any alternatives? Thanks for the replies

 

the fan, is annoying. this i speak from personal experience. my relay went out in mine. what i did is run a toggle switch with the fan with an inline fuse in the wires, i use a 20amp fuse with no problems and run the fan everytime i drive it somewhere. the ch fan fuse is located under the steering in that fuse box, be sure to check all fuses on it. there are also a couple fuses hidden on the car right behind where the connector is for the computer. check those too. also there should be a fuse right by the battery, check that as well. and double check to make sure that the main wire coming from the alternator is not hooked up to the battery directly, if it is, there in lies your biggest problem, that will kill every single cell in your battery everytime and youll go through batteries like its no ones business. then once again double check all your grounds and check all wires going to the starter as well. they can rub the dip stick and cause a world of trouble.

 

On the fan issue - most any autoparts store sells a fan controller - they run anywhere from $35 to well over $100, just depends on the bells and whistles. They probe the radiator thus no need to remove that plug, no need to worry about the OEM relay, etc. - they come with their own wiring and instructions. Very simple to install, and they work great.

I have the Flex-a-lite variable controller I got from Summit - best $100 I ever spent, Totally adjustable, works with dual fans, wiring for A/C, can add manual on/off switches, and it starts the fan at 65% initial speed, then goes to 100% if temp requires (less initial draw off battery). But any parts store should have models available with less options at lower prices, I know Advance carries a few on the shelf.

 

Thanks for the replies. When I have time, I'll look at the fuses, and revise it again. Hope I get it this time around. Restoration is being haulted until I get it running like it should. Thanks again.

 

Check for power at all wires to the plug that connects to the alternator. they should all show powert with the key on. One wire comes from the coolant fan relay circuit. This is the exciter signal that turns the alternator on. Its a dark brown wire on my 87. Can't remember the color on your 89.

 

noticed that my C-H fan fuse was busted, so i changed it, and it busted again when i started the car. What could it be? How many wires run to the starter? I set an appointment with a mechanic, charging $35/hr to find the problem. Sucks that I have to go that route. Any suggestions?

 

 

Any suggestions the ase doc gives you, listen and do them. Trust me he knows what he is talking about. Check all your ground wires for the fan, make sure there are no splits or cracks in the wire.

 

oif0709, Thanks for the props bro. Unfortunately, Im also old and forgetful. Thankfully, there are alot of others on here who also know their stuff. One is NINA. you can tell his posts by the multicolor font. Try unplugging the connector from the back of the alternator and replacing the FP/Fan fuse(what you call the C-H fuse). If the fuse holds this way, take the alternator in for testing. It probably has a shorted diode. If the fuse still blows, let us know. We'll tell you where to go from there.

BTW, $35/hr is cheap. My shop charges $90/hr.

 

I had Low Voltage problem, i bought it like that. The PO replaced the alt and battery and still had the low voltage issue. After i cleaned all the grounds and checked the fuses and still had the low voltage i checked the alt. plug and was a lil loose so i replaced it and checked for volts there. well that was it, i was getting 12V at the battery and 12V at the back of the Alt. 12V at the Red Wire of the plug and with the ignition on I was only getting 8V at the Brown wire. I knew i had a break somewhere in that wire so i replaced the wire from the Fan Fuse and got 12V. Check the voltage in the Brown Wire and see what you get.

 

Anytime, you have been extremely helpful in my process of restoring (slowly) my 89 camaro.

35 an hour is cheap, but make sure he knows what he is doing. You get what you pay for.

 

It is cheap But Prices are cheaper down here so im sure he will be ok, but yeah make sure he knows his stuff.

 

I have the exact same problem in my car! I'm going to start trying to diagnose it when the weather improves slightly. I have been going through batteries like nothing on earth, and the car has left me stuck places too many times that it has become redundant due to it's unreliability

 

Running your EFI vehicle on low voltage can be potentially harmful. Not only does it strain wiring and electric motors like your starter, fuel pump and cooling fans, it can also cause the ECM to experience faults if voltage drops below the ECM's regulated limit(about 11volts). If you have a failing charging system, get it fixed right away.

 

Thanks for the advice, everyone! I don't know what I would have done without the help and advice I've recieved from this forum. On a sad note, the weather hasnt been so forgiving, as most of you know. And I have not had the time to work on "Number 3", as I like to call her. But, as soon as I have some time, and daylight, I will do as previously instructed. Thanks again!

 

Keep us updated as I'll be out trying to sort mine when the weather picks up too.

 

I have been having the same problem kinda..when i get on the freeway with my firebird it charges up fine once your cruisin at 60 but if you let off the gas at all the battery indicator just nose dives..and forget cruising around in the city the car wont hold a charge long enough to sit at a red light

 

 

noticed the wire that goes behind the alternator (Red wire) runs directly to the battery. This is the one that should run to an alternative route? I replaced the wire because it was a little worn. Drove the car around my apartment complex, voltage gauge seemed fine. (key word seemed) Later the same day I drove it to the grocery store, my heart pounding with happiness that the car was working. Then i noticed the gauge gradually decrease. Next morning, it turned on a little weak. Turned it off and then on again, battery didnt have the juice. I tried to find the connector plug that goes to the alternator at the junk yard, no luck. I managed to find one off of a 93 caprice, thought maybe it would work. It is a little different, (the connections rod like prongs inside that plug are different).Will this work? Where could i find the right one? Thanks

 

 

I got the connector from o'reilly's. i think it was like 7 bucks

 

I am having a similar problem, I left my car at the parents house for most beginning of winter- only problem is I forgot to disconnect the battery. So when i went to pick up my car I had to charge the battery it stayed charged for a few days but now I have to jump it every morning before I go anywhere. It won't keep a charge over night, is it the battery or did I f*** something up?

 

 

schmitt55 - I'll check that out after work. Thanks. Hopefully they do have that though.

 

Yeah, i got mine from the Fredericksburg Rd.

 

I got it delivered to the shop today. The pigtail has three wires running out of it. The one that was on the car only had two. Is this third wire prong suppose to be connected to something, or can i ignore the extra wire? On the old pigtail the wires were one red, and one tan with a white stripe.

 

Mine had 3 wires the red goes to red which i think its your 12V at all times and the Brown/White went to the Black wire from the Orellys wire which its the wire that runs to the Fan Fuse and you get 12V once the Ignition is ON. the Third wire I believe goes to the Volt Gauge In the dash.

 

How do you check if a fusable link is good or bad?

 

 

Thanks NINA, that sounds easy. I will have a long day working on the car tomorrow. I hope I find and finally figure out this problem. Im glad the weather is going to be more hospitable.

 

So I had some time to work on the car. Changed the alternator pigtail. Fan fuse burned out when I turned the key. Disconnected the brown/white wire to the pigtail. Fuse didn't burn out at first start, or second. Closed the hood. Later that night I tried again, then it burned out. Next morning, changed the fuse, then tried it, it didn't burn out? What does that mean?

 

you have a bad ground

 

ok. I'll check them again. For the fan fuse, would it be other wires that could be doing this or is it specifically something having to do with the connections with that fuse? Might sound like a dumb question. How many ground wires go connected to the back of the engine. I know theres the one that goes directly to the firewall on the pass. side, but there are like four that run out of the engine harness to the block on both sides.correct? Thanks guys. I still havent given up, even though my girlfriend has. She hates my baby.

 

there is a ground that goes from the fire wall to your heads on the left and the main nuetral wire going to the block itself. there are grounds all over the place under the hood and in the car you just have to trace them out. if it is not a ground, then there is a split wire somewhere cause it to arc off something which will blow the fuse as well. and to much power going through one wire will do the same thing. but i would check my grounds first. if there not properly connected and held down the right way it will cause it to blow. make sure the wires are in good shape with no cracks or frays anywhere

 

it doesnt drop that low t5hat it stalls but it goes so low that when you try to take off from the red light it barely moves and backfires lke crazy..i had to buy another car because it just ept leaving me stranded and summers coming so m just trying to get it back on the road!!

 

That is a timing problem. Or a bad sensor. 02, map, ignition module, or ecm

 

So the charging system is fixed. hell yeah! the car is back on the road. I bought a wiring harness for my fan switch problem, car is overheating. The harness came with a radiator probe, relay, and fuse. I hooked it up, yet it doesn't turn on. I plugged the probe near the lower radiator hose. Anyone have one of these? Or have any suggestions for a similar setup?

 

What was the problem with the charging system so I have an idea when I go out and start messing around with mine.

Thanks,

 

I had to inspect and find why the brown/white wire wasnt exciting the alternator to start charging. Instead i ran that wire to another ignition 12v source, which sends power to the alternator as soon as the key is on. So the car runs great now.

 

That was my problem too. I was only getting 8V at the brown wire with the ignition on. I just ran a new wire and problem solved!!!! Its good to hear that you fixed it!!!!

 

Great news. I'll try and get some spare time soon to mess around with mine and report the outcome.