Forum Discussion
ledcomp
Oct 21, 2015Explorer
MEXICOWANDERER wrote:
Good technicians are LAZY technicians. I just got through sending the company a double-digit IQ grade, list of questions. I don't even wanna pop the hood and trace down the wire to the ECU. But before anyone grabs a 24" Stihl and goes to work allow the company to respond.
Well, I definitely fall under the lazy technician catagory. The problem i'm sure you are aware of is that it is a plesant surprise when a mfg/distribution tech can answer a question with an intelligent answer. I have run into a few in the RV industry like Shure Power and Best Converter.
MEXICOWANDERER wrote:
Case grounding is common on both A and B field circuit external regulators. For years I SOLDERED a wire with a 1/4" ring terminal atop a reg mounting hole. Both in the 540-series of Ford external regs and the 8312 series of MoPar external regs.
Do you have any idea how much current is on the ground path of these external regulators or better yet, what gauge wire for a 4' run?
MEXICOWANDERER wrote:
One of the two wires on the MoPar alternator is IGNITION SWITCHED POSITIVE. The other wire goes to the ECU. Disconnect one wire and use a test light to verify which is which. Key on but engine off. Remember this terminal.
Prepare to voltage probe this wire while it is connected charging with every accessory in the car switched ON. Drain the battery a little before starting the engine. Start the engine using a volt drop check. Meter positive probe on the alt output stud the neg probe on the field wire connection I told you not to forget.
Half a volt drop is too much. Fix it even if you have to do it using a Bosch type relay. Low voltage is low field current which is low alternator output. Total all-out ampere potential. If voltage drop is seen fix it.
I will check that next time I pull the engine cover, that happens as little as possible, what a pain in the *ss. How much drop is acceptable? Even if I pull power from the battery and go through a bosch relay I will still have 0.2 volt drop. Would that be acceptable?
Thanks for the help on this one guys, this is one of those long term persistant problems that iratate me. The funny thing is that it has been this way for the 3 years that i have had it. It is still on the battery I put in when I got it, It allways starts right up. I just dont like to see 12.8 volts at idle with lights and A/C on.
About Technical Issues
Having RV issues? Connect with others who have been in your shoes.24,333 PostsLatest Activity: Nov 06, 2025