ATX charging/plug connector question.

[jmpSHO2nd]

I have a 95 ATX with a SHO Source UDP (crank pulley). My charging system just doesn't seem to do the job with all accesories on (lights, radio, A/C etc). The alternator is new only about a week old and the problem was there before I installed the UDP, but when I installed the UDP I replaced the alternator because I thought it was going bad. I have a chip that SHO Source programmed and I had the idle raised to 1000 rpm to help the charging system at idle which is where I see the most problems. If I drive around the city with my A/C and radio on the A/C will eventually shut off and then the radio will shut off usually when I come to a stop or idle it in park for a few minutes.

With no load at idle it will charge a little above 13 volts and with a load it will drop to 12 volts and sometimes a little below. I am thinking I should replace the cables but i want a few opinions before I do it because it seems like a PITA to do.

 

[hawkeye18]

I think you need to replace your cables. If you have two alts that are doing it, that would tell me that the alt isn't the source of the problem.

But! There have been PLENTY of times when two or even three alts in a row were bad and didn't work right, so I wouldn't discount the alt completely as being the problem.

I have UDPs on my wife's 95 ATX with the idle raised to 950 and there aren't any charging problems.

 

[jmpSHO2nd]

I think you need to replace your cables. If you have two alts that are doing it, that would tell me that the alt isn't the source of the problem.

But! There have been PLENTY of times when two or even three alts in a row were bad and didn't work right, so I wouldn't discount the alt completely as being the problem.

I have UDPs on my wife's 95 ATX with the idle raised to 950 and there aren't any charging problems.

Yeah I guess I am going to replace the cables because I doubt the guy that rebuilds these things is going to swap out another alternator for me. I had a feeling it was the cables for a long time, I have had the car for 7 years and very rearely have I seen a good charge at idle, it usually always stays just over 13 volts and I always knew that was just a little low.

 

[hawkeye18]

The cables are honestly not that difficult to do. I want to say I bought 90 inches of 0 gauge cable and that was enough for the main positive and negative cables. I didn't swap out the cable that goes from the starter to the alternator (the last of the Big 3) but I can't imagine that'd need more than about 35 inches. Probably less than that. And you want to get at least 2 gauge, and preferably 0 gauge. ****, you can do 00 if you're feelin' frisky!

 

[FOMOCOTOSHO]

Also check the yellow wire coming from the alternator connector. It is a fuseable link wire that may be weak or bad.

Myself I just had this issue because I have fried 4 alternators in the last year on mine and I have the exact same setup as you. I decided to replace the connector plugging into the alternator so I went to the local junkyard to pick one up. When I cut off the connector on my car, I pulled down the wire wrap & found the connector had already been replaced and someone used those stupid butt connectors to connect them..as I wiggled them it came loose, so I soldered the new connector in and voila!

Dont' know if that's the same for you or not but just check em out.

 

[jmpSHO2nd]

So I just replaced my cables, I even did the one from the alternator to the starter and I still have the same problem. At idle with no load I can get 13.6 volts with my idle around 800 or 900 RPM and with my lights on it drops to around 12.5 and when I put the A/C on it drops to around 11.2.

I used 2 gauge wire, 4 gauge on the starter to the alt. I replaced both battery terminals and had a freshly charged battery that is maybe a year old.

So I guess the alternator comes out tomorrow and I will try another one. I am going to try and get my money back for this one and at this point I may try a FORD reman alternator. I just don't see how I can keep getting such bad alternators.

 

[jmpSHO2nd]

So I replaced the alternator today and get the same results, WTF!! I started looking at the alt. plug and it looks like it was replaced some time ago, not by me. I remove all the electrical tape and notice that one wire isn't connected to anything but there also isn't a third wire coming from the harness. I checked my 94 and it has three wires connected so now I am stumped because my 95 doesn't.

Does anyone know if a 95 ATX alternator used all three wires on the connector.

 

[jmpSHO2nd]

I found the answer the wire terminates in the harness some where so it is not used so now I have no idea why my SHO will not charge.

 

[jmpSHO2nd]

So as a last resort I swapped in an older battery from another SHO and at idle with everything on (A/C, lights with high beams, and radio etc..) it stays at 11.70 and it's pretty consistant, the weird part is nothing shuts off now like it did with the other battery.

That battery is a good battery (Interstate Mega Tron) and it is only about a year old so I don't know why it would make a difference because I swapped in an older battery.

 

[luigisho]

How long have you had the car and how long have you had a charging probelm?

When I had my GenI I went through 4 remanned units (at 3 different stores)until I got the 5th that finally charged properly.

 

[jmpSHO2nd]

I have had it for 7 years. I bought it with 112k and it now has 310k. This is really the first major charging issue I have had with the car.

 

[luigisho]

So, presumably the wiring has been the same configuration the entire time (unless there is a recent wiring failure). I would still point to the alt. as the defective part. Is there a way to check output from the unit along the output pathway from the unit to the battery?

 

[jmpSHO2nd]

I had two new alternators today and after trying both I ended up with the same result. I checked voltage at every possible point on that car today and I got the same reading everytime. The only time I got that car to idle without anything shutting off was when I installed another battery I had, voltage was still very low 11.70 but it was enough to keep everything on (A/C, radio, lights etc..) without any one of them shutting off. If it will stay like that I would be happy but I think that low voltage will eventually **** any battery I put in there.

 

[FOMOCOTOSHO]

You should take the vehicle into a shop and actually have both the alternator & battery TESTED, rather than assuming anything. Save some time & know where you start from. Most shops have comprehensive machines that can tell you more specifics about impedence, capacity, life, etc..

 

[jmpSHO2nd]

You should take the vehicle into a shop and actually have both the alternator & battery TESTED, rather than assuming anything. Save some time & know where you start from. Most shops have comprehensive machines that can tell you more specifics about impedence, capacity, life, etc..

I had both alternators tested and both passed. As for the batterry I am buying a new one today, I am going to try to get a new Interstate under warranty or I might try an Optima.

 

[luigisho]

They can sometimes test ok on the bench and then not perform well once the car is running for a little while. See what a new battery does but it still could be the alt. Like I said, I went through a ton of them before I found one that worked well. People at the autoparts store will tell you that these are a high return item. It's been this way for many years. Look in the GenIII section and someone bought a brand new Ford alt. and ended up being stranded shortly after.

 

[ViPER1313]

Did you replace the fusable links that attach to the + side post of the under-hood fusebox? If I am not mistaken, one of them is for + alt output, one is for the alternator's + voltage metering input. I know if they are burnt / kind of burnt, the alternator provide a weak charge to the system.

 

[SHOZ123]

Check the alternator voltage at the back of the alternator. Pos probe on the large cable nut and neg on the alternator case. You can also do millivolt drops on the cable to test them. With the engine running and an electrical load set the meter on millivolts. Ideally it will be negligible. But the higher the reading the higher the volt loss or resistance of the cable.

 

[jmpSHO2nd]

I replaced the alternator pulley with a smaller one and so far the smaller pulley and different battery seem to make a big difference. Later today I will check on what Paul and Viper said.

 

[FOMOCOTOSHO]

I had both alternators tested and both passed. As for the batterry I am buying a new one today, I am going to try to get a new Interstate under warranty or I might try an Optima.

x 2 on jmpSHO2nd. Bench tests are not accurate tests