Riddle me this...?

OK, update. Got some good info from people on here, and on the SRT-10 page on facebook. I was able to upload a video there easier. Someone noticed my volts at less than 12 while running, which apparently our computers need at least 12.5 to function properly. I changed the alternator.

I noticed that if I have the AC off, it stays around 14V, but if i cut the AC on it drops to 12v at idle. I have the JMB electric fan. Think bad ground somewhere would be causing this?
 
When was the last time the battery was tested? How many fans are in that kit? 1 or 2 motors? Try running only the AC with the blower on low speed to see if the system can handle it, you may be drawing too much amps. A good shop charging system tester should tell you this.
 
Had the battery tested last weekend. Battery was at top condition. Running 1 fan. I ran it on low and it sits at about 12.5v give or take. When I had it tested, it was saying that it was running at 12.2v and less than 30 amps (that is the lowest it could read)
 
Is the battery totally sealed or A maintenance free with removable caps? If you can access the cells do a specific gravity test. You can also use a volt meter to test each individual cell. Battery, cables and connections always need to be 100% first or you will just chase your tail. I would think the stock alternator should be able to handle that one electric fan motor with nothing else running. Try checking the serpentine belt and tensioner assembly. If the belt is slipping for any reason it will give your problems.
 
Check your grounds - in fact remove them, clean the contact area, apply some anti-corrosion compound and reinstall them.
 
Where are you testing your voltage at? The alternator output? The battery terminal? Reading from the gauge cluster? If you have a voltmeter measure from the alternator terminal to the negative terminal of the battery record this measurement. With the motor still running measure from the positive battery terminal to the negative battery terminal and record this voltage. Next measure the voltage at the fan with it off and again with it running. If you can get me this info I can help you troubleshoot this. Also does the voltage increase once you get the engine RPM raised above idle?
 
seethrough said:
Where are you testing your voltage at? The alternator output? The battery terminal? Reading from the gauge cluster? If you have a voltmeter measure from the alternator terminal to the negative terminal of the battery record this measurement. With the motor still running measure from the positive battery terminal to the negative battery terminal and record this voltage. Next measure the voltage at the fan with it off and again with it running. If you can get me this info I can help you troubleshoot this. Also does the voltage increase once you get the engine RPM raised above idle?
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I took it to Advance and they hooked up their tester or whatever, and tested. Where do I read voltage at the fan? Voltage increases substantially when RPMs are raised.
 
tank86 said:
I took it to Advance and they hooked up their tester or whatever, and tested. Where do I read voltage at the fan? Voltage increases substantially when RPMs are raised.
Click to expand...

Basically he wants you to check the charging system at idle unloaded record your voltage reading. Then load the alternator by turning on multiple loads ex: cooling fan/all lights/blower motor all these add a load to the alternator. The alternator should then compensate and kick up the output charge to the battery to handle the extra loads.

Good info: http://youtu.be/FTGz0PKIl84
 
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Another update. New IAC. Now at idle at a light voltage sits at 12v... then drops slowly to about 11v, and then just drops completely.
 
does any of your lights go dim, a/c blower slow down or quit????

sort of sounds like a bad cluster/volt gauge???
 
lights dont go dim. a/c blower does slow down at idle and pick up when i get rolling. i feel like im trying to find a needle in a haystack.
 
I just got my multimeter in today. It's late so I wasn't able to start it and idle and run various accessories. I did read from the positive and negative of the battery, and it says 12.31. I will get the other numbers tomorrow.
 
Ok, got my multimeter, read as follows:

Truck off (battery): 12.35
Truck on :13.68
AC on: 12.25



Thoughts?

Thank you in advance,

-Zac
 
Battery voltage is slightly low, should be around 12.6V with key off. Charging voltage should be around 14V so that is slightly low also.
 
Just changed idler pulley. At this point I am just throwing money at a problem and hoping eventually it'll work.
 
Did you try cleaning off the pulleys & belt with a wire brush? Sometime they get fouled with rust, road dirt or oil.
 
tank86 said:
Ok, got my multimeter, read as follows:

Truck off (battery): 12.35
Truck on :13.68
AC on: 12.25



Thoughts?

Thank you in advance,

-Zac
Click to expand...

Okay here's how it works. Truck has like a 135amp alternator so it should fully charge even at idle.

Your voltages look okay until you turn on the A/C .. Could load from A/C compressor and/or alternator be causing belt slip ? Is electrical load causing slip or showing a defective alternator ? Or is the load showing bad wiring on the regulator or even alternator output ?

The alternator uses a voltage regulator that's built into the PCM !!

So since you have low voltage under a bigger load it's a pretty short list :
alternator bad
belt slipping
PCM weirding out
bad [ie corroded / cracked / shorted / etc ] wiring

Try an amp meter on the alternator + and see what you get under your A/C load and no-load. That might point you in the right direction. If you get really crazy you can monitor the voltage on the regulator+ input to the alternator. As it approaches system/battery voltage the alternator is at full output. If the reg voltage is high and the alt output is low then you've isolated the issue to bad alt or belt slip. Could end up being something almost unrelated like a bad A/C compressor causing belt slip.

--CC
 
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10-1=9 said:
Did you try cleaning off the pulleys & belt with a wire brush? Sometime they get fouled with rust, road dirt or oil.
Click to expand...

No, I will try that tomorrow. I know all of them looked fine, but I will do it just in case.
 
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