What in the ....?????? Low voltage reading, yet full battery and alternator working.

Topic: What in the ....?????? Low voltage reading, yet full battery and alternator working. (Read 19663 times) previous topic - next topic

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #30 – June 17, 2014, 01:34:47 PM

Your alt output is a little low at 13.8v and the link getting hot could mean you have a heavy electrical load on the alt.
Maybe because the battery is discharged.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #31 – June 17, 2014, 03:57:49 PM

I'm thinking that connector has had issues for a while now from the looks of it. I cut it out and am going to hard wire those 3.... After that, I'm changing the connector on the alternator. I'm not gonna upgrade until this is fixed.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #32 – June 17, 2014, 04:13:45 PM

I don't know if you really need the 3G. I've got a stock electrical system and the 2G does fine. That's why I keep putting off the 3G upgrade. I'm waiting till the alternator s out first.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #33 – June 17, 2014, 06:56:41 PM

Quote from: V8Demon;434921

I'm thinking that connector has had issues for a while now from the looks of it. I cut it out and am going to hard wire those 3.... After that, I'm changing the connector on the alternator. I'm not gonna upgrade until this is fixed.

The unused red wire may be hot with the key on. If so, you don't want it grounding out.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #34 – June 17, 2014, 07:37:56 PM

The problem with the stock setup is the wiring. even though its a 60 amp alt, it only puts out about 35 amps at idle. my smallest model airplane pulls over 30 amps @12.6 v's.

just figuring the headlights and a 200watt radio uses over 20 of those 40 amps.

the wiring is way underdone.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #35 – June 17, 2014, 07:40:14 PM

It's wrapped and waterproof now. Just finished. A plague upon the last person who did that pigtail on the alternator. It was a mess. Redone.

Bad news. The link still gets hot... I can find nothing else that stands out.....

Just redid those tests...
0
0
0.761

So by fixing obvious issues this has somehow gotten worse? From what I understand isn't the 3rd test supposed to show around 2.4 or so?

Also: Battery with key on and door open 11.74
Start car 13.68
Car ran for 15 seconds and the oink got noticeably uncomfortable to touch.
Shut car off ignition on door open a total of 30 seconds from first reading 12.24

Isn't that quite a bit of increase in 30 seconds?

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #36 – June 17, 2014, 09:14:46 PM

Ok if you have the alternator with the plug arrangement instead of the post and nut you are going to have issues. Does your car in fact have an external regulator?? If so in my opinion you are wasting your time trying to repair it. Just me. Those connectors burn up and cause fires. There is a couple of service bulletins on this. If i was doing the job i would rip out all those green connectors remove the external regulator and wire in a 3G and be done with it. Any wiring that gets hot has to much resistance. That is why it gets hot. If it is your alt feed wires to the solenoid that is the main charging wire and it has to much voltage drop. .Better fix it and get rid of that outdated alternator. Plain and simple those alternators are GARBAGE and under rated drastically for the car and it's electrical load. Have a good evening guys. just my thoughts on the issue!!

Note if the alternator has an external regulator it is a 1G If it has a plug battery feed it is a 2g with internal regulator. And a 3g is internal regulator with a battery post feed with a nut. Hope this helps. Show a photo of your setup for clarity on the issue. If you are not getting 13.8 -14.7 at 1500 RPM'S you are not charging.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #37 – June 17, 2014, 10:06:56 PM

The 3g 130 amp kit I linked comes with a power wire that would be used instead of the black/orange wire. Trust me, I know it's time to upgrade.

I'm assuming if I upgrade the power feed line I SHOULD upgrade the ground wire too....
Any suggestions for that?

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #38 – June 17, 2014, 10:12:13 PM

What's your ground now?

When i replace mine i just buy a cheap 6 guage post to eyeles from the parts store. no idea what stock should be.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #39 – June 17, 2014, 10:14:22 PM

All the grounds are stock right now.

Also I just realized; I have a high torque mini starter. It's a Powermaster XS model #9503. AFAIK, this is like the later PMGR starters. Been in the car for a while now....

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #40 – June 17, 2014, 10:23:10 PM

No need to mess with the grounds as long as they are tight and clean. Once again post a photo of your setup. Wiring issues are always tricky when i try to help people out. They seem to be uncomfortable with it.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #41 – June 18, 2014, 01:38:12 AM

Quote from: V8Demon;434932

It's wrapped and waterproof now. Just finished. A plague upon the last person who did that pigtail on the alternator. It was a mess. Redone.

Bad news. The link still gets hot... I can find nothing else that stands out.....

Was the original fuse link green or black? I think there is a error in the 87 EVTM. The 88 EVTM shows a green 14 gauge link instead of the black 16 gauge. If it should be 14 gauge, that would explain why it is overheating.

Quote

Just redid those tests...
0 I think you miss probed the first two. they have a direct circuit to the battery, unless the link blew again.
0
0.761 I confused the issue with this test. With the cable unplugged and key on it is close to battery voltage. Cable plugged and key on it signals the Reg to turn on the Alt field current and the reg provides the ground to turn on the Alt warning light on the dash. With the engine running and the Alt has an output, the voltage from the Alt to the S terminal on the Reg causes the Reg to remove the ground from the Reg I terminal and the warning light goes out. So with the engine running, the voltage should be near battery voltage.

To sum all that up, if the Alt warning light comes on with the key on and goes off when you start the engine, all is good.

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #42 – June 18, 2014, 03:57:38 AM

The fuse was originally black when I bought the car. It was actually labeled 16 gauge. I replaced it with 16 gauge after it went the fist time. This time I had an original one that's built into that wire jumble. I replaced all of that, removed the wiring connector that was coated with corrosion and spliced everything together. Also I replaced the connector on the alternator itself which is remaining cool when this is all running. The last line k I replaced lasted 5+ years without a hitch.

I often wonder why the one side has both the yellow AND black/orange on one link in the wiring to the block and on the other side they are separate. All 3 run to a crimp and go to the ring terminal on the starter solenoid. The other 2 stay cold.

The wiring back towards the link steps down at some point to 12 gauge as opposed to the 10 coming from the alternator. As far as I know and can tell it's stock other than what I've just done, but I have not changed any sizes... I'm guessing it changes where the yellow wire runs into it labelled s492 in the evtm diagram posted earlier.

Pics tomorrow. Frustration abounds......

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #43 – June 18, 2014, 04:10:40 PM

OK. I've decided to just replace that ENTIRE wire section instead of just the pieces I could see that were bad. I picked up 8 foot of 10 gauge wire and 4 foot of 12 gauge. Should be plenty. I've also found another ground strap on the 5.0 motor I have in the backyard as well. It's going on. Not today though. I spent entirely too much time on this already this set of days off and I'm actually gonna enjoy today 'cause I gotta work tomorrow. I'll pick at it at my convenience as this; after all is not a commuter that NEEDS to be fixed this very moment.

In the meantime here's pics. Keep in mind I left everything in the area of the starter solenoid apart from one another so I could check to see if that one link got hot....

What in the ....?????? Low voltage reading, yet full battery and alternator working.

Reply #44 – June 18, 2014, 09:47:49 PM

The part you are holding is not the link. The link is the actual wire link connected to that splice in your hand. If the splice gets hot it is NG!! That is what i thought you have a 2G with spade connectors. That unit is junk and should not be used as they are a fire hazard. Ford has a TSB on the issues and repair procedure.
Ford bridged the battery feed at the alternator and made it a single wire to the solenoid at the alternator because the spade pr0ngs were not rated for a constant 60 Amps. So they doubled them up at the connector and bridged them together in the wiring harness. This created a heat situation at the connector on the alternator and melted it and in some cases caused a fire. Ford has a replacement alternator with a lug to fix the issue. But if you are going to up date might as well get a 3G and do it correctly. I know you do not want to do it now but the risk of melting that connector is real and dangerous. Either way you need a new feed wire to the solenoid and the alternator. I would suggest a Number 8 gauge fused with a 100A maxi fuse and holder which is much better than a link and bridged together with your new plug. Or better yet 2 separate wires from your new plug run all the way to the solenoid separately and bridged at the solenoid in stead of bridging them at the new alternator plug you installed. This will eliminate a splice and there will be no splices from the alternator to the starter solenoid other than at the new connector. Then s all the factory wiring with it's connectors and resistive connections. Another words a dedicated number 8 Gauge wire directly from the solenoid to the battery lugs of the alternator. Or 2 separate number 12 gauge wires fun to the solenoid separately. One from each of those battery lugs on the alternator. This will fix all those sketchy connectors that are getting hot and building voltage drops in the system. And make sure all connections are not crimped. But crimped and soldered. have a good evening guys