I couldn't post this in the electrical forum, so I am posting here.
Since getting my EZ30R equipped Tribeca back from the JDM shop I have not been able to resolve the following issue:
I am experiencing a poorly charging electrical system with all accessories running at idle. The vehicle starts off charging at about 14.4 VDC, but after about 2 minutes of running voltage dips down to about 12.2 VDC and continues to fall.
Idle is about 750 rpm. Current Draw is about 78 Amps with all accessories running as checked with my DC clamp meter.
The low voltage appears at the alternator terminal, not just the battery terminal.
I tried grounding different parts of the engine block to the battery negative terminal to no avail.
The vehicle has a brand new Advanced Auto Autocraft Gold battery and I have tried alternators from both engines to no avail.
If I rev the engine up a few hundred RPM(s), the alternator is able to reach 13.8 VDC.
I recently had a JDM engine put in by a JDM engine shop due to a head gasket issue on my EZ30R Tribeca.
Since I got the vehicle back, it has naturally had a few issues. First the power steering pump whined away and was dumping fluid onto the top of the motor. I asked for my old pump back and that worked with the exception of a small unknown leak at the pump. Unfortunately my old pump was missing the sensor with the wire at the back of the pump. It seems like the shop broke that off and put the JDM pump on instead.
I only mention this just in case that disconnected wire might be the cause of my issue. I doubt it because I connected the JDM pump wire to that wire after installing the original pump and grounded it. I ran the engine and the voltage still continued to drop so that wire likely has nothing to do with it.
The JDM shop is pretty far away so it's a MAJOR hassle to get it back over there.
I had the EXACT same thing happen to my Dodge Caravan and no one could ever answer.
In that enthusiast forum, the first week or so were arguments back and forth about whether or not the alternator could actually maintain voltage with all accessories running at idle. Come on now, these are family vehicles and the Tribeca is a luxury vehicle! I'll NEVER believe that voltage is supposed to go so low that your rear blower motor fan shuts off! I could be stranded with my family if I get stuck in the every day 50 mile bumper to bumper traffic encountered in the DC area!
The second week or so I was able to convince someone to check their voltages with all accessories running and they confirmed voltage well above 12.5 VDC.
The third week or so I purchased a clamp meter where a few folks mentioned that the current draw at idle was a bit too high, but could offer no solutions as to why.
The 4th week or so I ended up giving up and getting a heavy duty alternator which burnt up in no time.
As a result, for the last 4 years I have run a smaller alternator pulley on that Caravan which allowed me to get more alternator juice at idle. Unfortunately, I have to replace the alternator every 8 months and hope that it didn't burn up in the middle of a long trip with family and pets aboard.
In that case, I re-grounded everything with thick gauge wires and ring terminals to no avail and the grounds on this Tribeca are pretty doggone hard to reach.
I feel like I am headed for a repeat with this Tribeca and I'd rather sell it as is than drive myself insane or delegate it to "junk pickup" duty like I did with my Caravan.
I think that is just going to be an unsolvable issue!
Can anyone help?