the last two nights have been a little cooler then normal and both times I made a short trip to a friends house. Shortly after leaving I noticed that the RDDP led power led was red indicating that it was at 15v or over. When I looked at my voltgauge mounted in my fuse holder it was reading 15-15.2v and it has never done this before. If I crank the stereo I can pull it down below 15 to around 14-14.5 with the heater on, lights on ect but otherwise it was high on both trips.
Now as I said it has been cooler then normal, and the truck was also out in the dry hot desert for the last 10 yrs so it is also in a much wetter environment but again I didn't think it would matter.
Is this the beginning of the end and I should start lookin for a HO alt finally? If anyone tells me to install a cap I will be happy to do so as soon as the bend over ................
Yeah, that may be a sign your regulator has started to go out, especially if you weren't running higher voltage before. Keep an eye on it and make sure the voltage doesn't go much higher, otherwise you could break your battery, or even electrical parts like your ECU or your amp
I have never heard of it going up before it went out so I was a little confused and concerned and kept a close eye on it.
I had also just wondered if it could be the alt reacting to the extreme change in climate in going from sunny phoenix to the suddenly chilly(but beautifull for you canadian folk) 40s. Could the change in temp cause the alt to be more efficient?
I would personally lean towards the idea that after beating on it with my octane LE for almost 2 yrs in the 110+ temps in the desert has led to its demise but just never seen one start chargin too high suddenly.
Voltage regulators can fail by allowing the voltage to increase too far. It might be worth removing it and having it tested by Autozone/etc. to see if they spot any issues. Also, I know this sounds dumb but have you checked your voltmeter(s) are reading the right value? I had a multimeter that thought my battery was 15v as well, but it turned out that the multimeter was just miscalibrated and reading high.
The cold weather would improve efficiency, but this should be seen as more amperage, not voltage.
This is the same problem Matt was having when he first installed his HO alternator. I believe it was his regulator, metal had gotten in there when he drilled a mounting hole......I think, I know Matt had this problem not too long ago......he removed his Powercore IIRC, it may have been causing problems.....Matt where are you ?
I actually have 2 meters, the RDDP output as well as the one built into the fuse block. The stock dummy gauge showed high but didn't get into the red zone which was the only reason I didn't pull over and park it but I know that the ford gauges are dumbed down. I had the mustang on the dyno this summer(in phoenix again, 114 it showed on the test) and the stock temp gauge showed only a little high while the dyno gauges showed that it was already to the point the computer was taking timing out to cool it.
Now I hopped in the stang today and noticed the voltage in it was a super solid 14.6. I cranked the stereo as loud as I could and put the lights on and it didn't budge below 14.5. This alt is a HO 200A but back in the desert it would get into the lower 13v range in normal operation at night. This made me wonder if the all the heat they were exposed to there didn't cause enough expansion(the truck was there 10 yrs) and now the cold weather contraction has caused the tolerances to change, effecting the output? Dunno, just shooting ideas in confusion, both cars at once?
DB- the alt in the truck reading +15v is a stock alt, the ho is in the stang.
Alternators almost always put out a higher voltage in colder weather initially. Initially meaning when you first start the vehicle. After the engine and the engine compartment and the alternator have had a chance to warm up, about 15 minutes should do depending on the outside temp you started with, it should drop back to the numbers you are used to seeing or just a bit above. Hot weather almost always will show a slightly lower voltage again taking all the other mentioned factors into account. If after everything is up to normal operating temperature you are still experiencing this high of a voltage, yes, you have a regulating issue.
Hot days at idle for a correctly functioning charging system you could see as low as 13V. As soon as you come above idle and or at cruising speed you should be at 14.5 and no lower than 14V. As in the last post this is with the vehicle warmed up to normal operating temperatures.
................
