|
Long story short I've been having intermittent issues with the voltage regulator on my jeep for the last few years, recently it's gotten to the point where I have replaced it 2 times in the last year using junk yard regulators that I cut off harnesses as the voltage regulator located behind the alternator is a dealer only part and I was quoted $255 for that little black box. As it is I ended up having to cancel a wheeling trip this last weekend as it went out and kind of left me high and dry, but works intermittently if I tap it lightly so I'm pretty much done with it at this point. When I installed the last 2 I replaced I soldered the 2 wires that needed to be spliced and made sure they were wrapped up good to prevent a short and have the voltage regulator grounded to the engine block just like the original was but these things keep going out and I can't figure out why. I don't believe I have a short anywhere as I had another unrelated electrical issue a few months back and I ended up having to unravel and re-wrap about 90 percent of the engine and tranny harnesses to find the short. My question is kind of two fold, first what could be causing these to go bad so often and secondly is there another alternative that you guys have used successfully, like an external voltage regulator from like a Ford, Dodge or Chevy that you could easily find at like an AutoZone or some local parts place.
Thanks,
Fred R.
The regulator is in the pcm. I thought that box was the field switch.
I would try a different PCM if you have access to one.
This link may help you if you want to do the external regulator - http://www.thedieselgarage.com/forum...ad.php?t=58251
Last edited by rstrucks; 07-21-2010 at 09:53 AM.
from the fsm.
that box on the alternator is only the field terminal unit.VOLTAGE REGULATOR
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulating
circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
Operation: The amount of DC current produced
by the generator is controlled by EVR circuitry contained
within the PCM. This circuitry is connected in
series with the generators second rotor field terminal
and its ground.
Voltage is regulated by cycling the ground path to
control the strength of the rotor magnetic field. The
EVR circuitry monitors system line voltage and battery
temperature (refer to Battery Temperature Sensor
for more information). It then compensates and
regulates generator current output accordingly. Also
see Charging System Operation for additional information.
Last edited by ratmonkey; 07-21-2010 at 11:11 AM.
Thanks ratmonkey, saw your post last night but couldn't post from my phone (just moved and no internet access at the new place yet), after seeing it I ended up taking apart that "box" that's posted behind the alternator and all it was was just the 2 wires and the ground cable going into it and the cables were just boxed in with that plastic essentially, nothing else. Cleaned up the wiring and replaced the connectors but it still doesn't work, which is funny because replacing this "box" fixed the problem the last couple of times. Funny thing is I still have the problem but if I tap the alternator in the same area the black "box" used to be bolted behind it the system will start charging again . I had the alternator and the battery tested yesterday and they both tested good, but I think it might be the alternator so I'm going to get one today after work. I also took the entire harness in that area apart inspected and cleaned it and the alternator & battery/terminals.
rstrucks, I don't have access to a PCM so I would have to get one from a JY and hope it works. The first time this happened I got a quote from the dealership for $475 for the PCM or $200 to diagnose it but it would have to be sent off and would take 4-5 days as they said they could not see if it was bad with just the basic scan tool. Correct me if I'm wrong but I believe that the PCM has to be from the same Year and engine combo as mine so as to work? Thanks again for the help, I'll update the post with the resolution if/when I find it.
Thanks,
Fred R.
My best guess as to why it happened is that there is an intermittent electrical problem (probably a loose wire causing a short or some sort of faulty logic in the PCM) somewhere else is causing that box operate out of its intended electrical specs and eventually fail. Because it's intermittent, that would explain why replacing the box worked -- until it died again.
If that box's inputs are fed by the PCM, I'd put my money on the PCM. I've had really really weird intermittent electrical issues for a while until I replaced the PCM and they all magically went away.
Thanks that helped as it fixed the issue last night, I ended up using the a write-up on another Cherokee forum were they used the same Pre-89 dodge external voltage regulator but said to splice it into the green wire w/ purple tracer on the alternator with the blue wire on the regulator and the solid dark green wire on the alternator gets cut and sent to the light green wire on the plug for the regulator.
PM sent... Might need one as a back-up
Thanks again to everyone for all the help again.
Fred R.
« Previous Thread | Next Thread » |
Thread Information |
Users Browsing this ThreadThere are currently 1 users browsing this thread. (0 members and 1 guests) |