JustJeff

iTrader: (13)

My car apparently ate an Optima yellow top. It's under warranty and was replaced at no charge to me. But the car previously was eating red tops and the parts store allowed me to pay the difference to upgrade to a yellow top when my red top died.

I hardly ever drive the car so it sits for some time before I have opportunity to work on it or drive it. I put a new TPS on and was trying to set it using voltage and that was the last time my yellow top saw 12v. I went out the next day to find my battery down to 4v and the trunk lid not latched and assumed I simply ran the battery dead. I don't own an AGM charger so I took up to the shop where some friends work to get it charged. 3 days later it was still showing 4v and they exchanged it for a new one.

I have a taurus efan and a modded S5 alternator (130amps) and I know it needs to see 1-1.5k RPMs for it to be charging.

I want to test the alternator during regular driving to see what voltage range it's charging. My OEM gauge is occasionally all over the place (more so than simply needing to keep idling RPMS up to get it to 14v) and want to verify whether it's reading accurate or not. I can either buy a volt gauge or digital display but is there any reason I can't simply run a wire from my alternator L terminal into the cockpit of the car and put my meter's alligator clips on the wire. Clip my other meter lead to a ground wire?

Tui

iTrader: (2)

Just connect your alligator clips to the main power wire that connects to your ignition switch and the other to the dash frame. A couple screws to drop the sheering wheel shroud and easy peazzy.

If you have an S4 wired for an S5 alternator, check the wiring. S5 needs a constant activation, so needs a wire directly to the battery. S4 interrupts the activation at the ignition switch which would cause a drain to your battery.

satch

iTrader: (1)

The voltage gauge takes its reading from the meter fuse so all you would have to do is take the reading from this meter fuse.

JustJeff

iTrader: (13)

S5 convertible and wiring

So the meter fuse will show me between 0-14.7v(hopefully, not higher)? Or will it show 0-5v and the OEM meter calibrates the dial off 0-5v?

satch

iTrader: (1)

It should show you the output of the alternator.

JustJeff

iTrader: (13)

^ Thx Satch, I'll try it in the AM

Tui

iTrader: (2)

After market alarm or head unit that received a constant hot? Aftermarket anything else that receives a constant hot?

Something is seeing your battery 24/7 draining it, and a not stock something is almost always the culprit of the symptom you are dealing with.

Try disconnecting anything aftermarket and let it sit for 48 hours. If no drain, then reconnect one at a time. This is of course an obvious approach, but still your best bet.

JustJeff

iTrader: (13)

Finally got around to testing a few things, both alternator and replacement TPS. I believe both are failing.

The modded alt never saw above 14v highest it ever read at 1-1.5k rpms was 13.7 and as the engine warmed up the readings got lower. After the engine got to temp it was reading 13.42


Satch is there any loss of voltage between the alternator and the meter fuse? Also my ground wire for testing was very long...15' or so of it all spaghetti noodled at my feet. That's not going to account for any loss is it?

Related oddity, I believe I bought a bad used TPS. I tried setting it with voltage and resistance. Can the bad alternator throw off all my sensors and should I wait to condemn the TPS till I have a proper alternator?

satch

iTrader: (1)

The drop should be rather minute. If you were worried about the length of the ground wire, you could use the bottom row far left wire (Black) of the circuit opening relay as it is a ground.

When setting the resistance for the TPS it should be unplugged from its harness.

JustJeff

iTrader: (13)

I thought of something (remembered) while watching World Cup. A while back Jackhilde gave me some advice on alternators. This is how I remember it.....That the alternator voltage will vary with the charge on the battery. So as the battery gets fully charged the alternator voltage will drop some. Is this correct? The drop in alternator output could have been because the battery got topped off, or so to speak?

That a real test would be to idle the car with the efan running so there is a nice drain on the battery and then see how the alternator is behaving?

I've got a Taurus alt that I can put on and I'm really close to ditching this modded alt. Problems with Taurus alt:

1. Need to make a mounting bracket
2. Mounting bracket will probably have the alt sitting too high and I'll have to remove my Infini IV strut bar. I've learned that a strut bar on a convertible is like night and day difference.
3. Alt will sit high and I'll have to get a longer/taller turbo to charge pipe coupler so that the alt will fit under the TMIC

I may simply ditch the efan, go back to clutch fan and get an FD alt.

Can't decide whether to keep fighting and wondering about this modded alt, Taurus alt, or give up on efan.

About the TPS, I set it via voltage first (warmed up engine, key to ON, and connector plugged in and reading off G/R wire) but the replacement was way off. My DMM was reading .534v and I had to turn the adjustment screw all kinds of times to get it to 1v. I had to adjust the TPS so far that I was concerned that the replacement TPS was bad so I then went to resistance for a 2nd reference. Connector unplugged with 1v at TPS, resistance was at 2.6k ohms for narrow (between A and B IIRC). So I adjust down to 1k ohms open throttlebody to WOT and my resistance pegged to something like 15kohms.

jjwalker

I would consider your readings with the multimeter acceptable if the battery was completely charged and minimal load is being placed on the alternator.

13.4v is normal on a hot engine at idle, and should climb to at least 13.8-14v as you rev past 3k rpm. Remember, the battery charging voltage is 13.4 volts. Where the battery starts to release hydrogen gas is at 14.4v. Also, keep in mind your optima battery has a lower charging voltage threshold than a typical flooded battery.

JustJeff

iTrader: (13)

Follow up question: In the last 2 yrs I've gone through something like 5-6 Optima batteries while the car sat, being driven and worked on rarely. I went with this modded 130a alt, taurus efan and I had an optima red top. I was killing red tops but they have been under warranty and I know some of the guys working where I bought it so I get some favors.

I had been wanting to switch to a yellow top and had been through 4 red tops. A friend working there agreed that yellow top is better suited if I'm not driving daily with it. He cleared it with his boss to let me pay the difference on my replacement battery and get a yellow top. BUT I just killed a my first yellow top. All I was doing was warming up the engine so I could set my replacement TPS. I came back the next day and my battery was at 4v and it never took a charge and was replaced. Obviously I don't want to kill ANOTHER battery cause there is going to come a time when friends at the store can't pull any more favors for me. Honestly I'm surprised it hasn't happened yet, cause I've been through $1k in batteries at no charge to me.

Can my alternator sporadically be overcharging and killing them? Like maybe once the fan starts running, the battery drains and the alternator voltage regulator spikes over 14 volts and starts damaging the Optimas?

If it's not my alternator under or over charging where can I start looking for what is killing my batteries?

satch

iTrader: (1)

Have you checked for amperage drain. Can't remember if you mentioned this already.

JustJeff

iTrader: (13)

Finally had time to mess with it again. Looks like my alt is draining batteries. I put my DC amp clamp on each positive cable (individually of course).

I have:

1. 4 ga going to starter
2. 4ga going to alternator
3. Not currently connected I also have a 4ga going to amp distribution block
4. 8ga going to engine fuse box
5. 8ga going to efan

All of them read .1 amps, BUT the one going to the alternator, it read .3-.4 amps. I disconnected the alt cable from the battery over night and my battery only drained down .002v.

I guess I've got my answer on the alternator without doing the voltage regulator test. Now the question is finding out if my car is killing the alternators or if it's a crappy modded alternator that keeps giving out. The alternator has been replaced one time at no charge to me from the shop I bought it from. I'll be contacting them to let them know their alt just killed my yellow top. But how can I test my wiring on the charging system or even the fan to see if that is the cause of my alternator taking a crap?

j9fd3s

iTrader: (3)

just a couple of thoughts

A. optimas are fragile. they don't like heat, cold, vibration, overcharging, or under charging, so basically they aren't a very good battery to use in a car.

2. a Mazda alternator will charge between 13.6-13.9v, a newer car will be a little higher. 13.4 is a little low, but i usually measure at the b+ terminal, which would be a little higher.

summary; in short i think the problem is that you have an optima, and if you just plopped a no name lead acid in there, you wouldn't have a problem

JustJeff

iTrader: (13)

You don't think the alternator will drain a lead acid battery? Am I wrong in assuming that the alternator is bad regardless of which battery, but that the battery I chose being fragile exasperates the problem with the alternator? In other words I should replace the both the alt and the battery?

I'm sure I can find someone who will buy the optima, maybe replace it with a Deka

RX7(613)

iTrader: (9)

Have you checked your security module. The oem one. These are notorious for draining batteries. My last 3 Fcs some how had defective units and would drain battery at various intervals.

I don't think you are getting defective batteries, you must have a drain if you have gone through so many.

mind you I stopped buying red tops a while ago as I found no benefit to them in these cars.

JustJeff

iTrader: (13)

S5 OEM security is in the CPU at the driver kick panel. IIRC that was replaced with a new one a couple years ago. That being said, I believe I found what was draining my battery. The positive battery cable going to the B post on the alt was showing parasitic draw of .3-.4 amps. I left it disconnected over night and in the AM the battery was still at a solid 12.64v, it had dropped .02v overnight.

Question that still remains is whether the alternator was also under/over charging the Optima..which might be a moot point if the alternator is being replaced anyway.

For the record I don't think I"m getting defective batteries either, but they have all been under warranty and I'm friend with a couple of the guys who work and manage the store where I got them so thus far they have always been replaced. I made a mistake buying the red top. I was thinking the red top was the one you wanted for when the car is not a daily driver. My buddy at the shop corrected that mistake by letting pay the $15 difference between what I paid for the red top and what the yellow top cost. I wasnt' using the red tops like they were designed and was a contributing factor to the red tops dying. A week or so ago I killed my first yellow top. Before I even switched to yellow top someone had suggested I switch to Deka and with the yellow top being brand new I may sell it and make the change.

JustJeff

iTrader: (13)

Follow up question

Are all AGM batteries fragile, or is it just Optimas?

Akagis_white_comet

iTrader: (4)

Deka batteries don't seem to have the frailty of the Optima ones that you've encountered. I have run my Group 48 Intimidator (70AH vs stock 55AH) into the ground at least 25 times since I bought it and to keeps coming back for more, using nothing more than a normal battery charger from Walmart. Granted, my battery is in the passenger side storage bin and not subject to the heat or cold as one would under the hood. In all fairness, it had only seen overcharging for about 3 minutes before the breaker disconnected it (voltage regulator failed on Taurus Alt).

Aaron Cake said they kick ***, so I bought one based on that and I've been thoroughly impressed. It was WELL worth the $170 to get from Remybattery.com