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Topic: installing Cole-Hersee  #48160 3 post isolator (Read 2437 times) previous topic - next topic

installing Cole-Hersee  #48160 3 post isolator

Tomorrow I am going to install a new Cole-Hersee  #48160 on my 2005 U270, which has 3 posts. I understand the wiring diagram enclosed with the new device. On my existing 3 post isolator, I notice there is a 4th wire connected. What would that wire be? Its not shown in the wiring diagram > thanaks to everyone in advance
2000 U270 34' WTFE Build 5756 "Ole Red"
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #1 –
The big terminal on the left #1 is for the engine battery. Middle terminal #2 goes to the big + lug on the alternator. Right terminal #3 is for the coach batteries. The small 4th terminal on your old one went to the ignition solenoid (hot with key on). Hold the isolator up and read the label left to right.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #2 –
I tried to add to my post but was not successful. My dilemna is that I saw the wiring as I looked thru the engine compartment from the rear. The tech had to order the Cole-Hersee  #48160 3 post isolator and it arrived this morning. Unfortunately the tech had an emergency, so he had bolted the house and coach battery wires, along with the alternator and this 4th wire, all together and securely taped up.  I wish he had taken a close up pic of the existing wiring. He said I could drive the coach home if I were willing to do the install myself, which I have chosen to do.
I realize I am at risk with the batteries tied together if they were to discharge, but I am now plugged into 50 amps and have minimal 12 volt devices running. I am assuming this is the same as having the "boost" switch on. Is that a correct assumption?
2000 U270 34' WTFE Build 5756 "Ole Red"
2014 Honda CRV
Washington, Vermont
Lady Lake, Fl,  Independence, VA
Former owner of 2002 U320, 2003 U320, 2005 U270

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #3 –
Why can't people do their job right? No, you will have higher voltage at both batteries now. About a volt too much. Connect the cables as in the instructions that came with your new isolator.

The isolator lowers the voltage that is intentionally a bit higher from the alternator to compensate for the isolator. You should have left the coach where it was. I would make him come out to your house to finish the job. Sounds like he's learning at your expense. Now, he will probably install the wires incorrectly. The last owner of our coach did exactly that so it's pretty common.

This is the reason isolator alternators have a different part number.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #4 –
Use your coach schematic to identify the cables. The number on the schematic should match up with the number at the end of the cable if it has not faded.

Before ANYONE works on their electrics, identify the cables, use a label machine if you can't read the codes and then take a photo of it with a smart phone.

And don't take your coach to expensive shops that do a lot of race advertising but train the mechanics at your expense.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #5 –
Quote from: Pierce & Gaylie Stewart –
And don't take your coach to expensive shops that do a lot of race advertising but train the mechanics at your expense.

Pierce
Unfortunately mechanics or any other techs have to be trained. Every service industry goes through this. Qouted price has an allowance for this, and labor & material costs should never be adjusted, unless advised, documented and approved due to unforeseen circumstances. Techs incompetence resulting in damage is typically covered in a qoute. Time and materials based on historical experience with a company is still somewhat a crapshoot.  Best value is becoming self sufficient at 75% them hire a true pro. My 2c worth.
Old Phart Phred, EIEIO
89 GV ored 36' #3405 300 hp cat 3208 ATAAC side radiator, mountain tamer exhaust brake

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #6 –
While I agree that the wiring should be installed properly, wiring alternator, chassis and house batteries together (and assume the sense wire as well) will NOT result in excessive voltage.

Since there is no diode-based isolator that reduces voltage, the only difference is that the voltage the alternator produces will not have to be .7 VDC high to compensate for the loss in the diode-based isolator.

Most of our boats are wired this way (actually with a mechanical switch).  But with no diode-based isolator.  NO excessive voltage.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #7 –
Our ran almost a volt high before I corrected the incorrect wiring.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #8 –
Quote from: Pierce & Gaylie Stewart –
Our ran almost a volt high before I corrected the incorrect wiring.

Pierce
Pierce,

Yes, there are some ways that improper wiring could cause high voltage, but not if  alternator B+, chassis battery, house battery and sense wire are all joined together. Most high voltage situations have to do with  resistance on sense wire (artificially telling the alternator that it senses lower than actual voltage at the battery).

Heck, on a charter sailboat many years ago, I used a bolt and nut to connect both battery banks and alternator B+ together for charging.  Disconnected and put hot ends in old pieces of rubber hose when not charging so no dead shorts. Did this for 3 weeks in the out islands of the Bahamas, as no parts were available.

Have also wired our Foretravel with a simple marine ON-OFF switch, replacing the diode-based isolator.  Alternator B+, chassis battery and sense wire to one lug and house battery to the other.  Very KISS theory. And gives you many options in terms of battery combine, whether to charge the house bank while driving, etc.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #9 –
Quote from: wolfe10 –
Have also wired our Foretravel with a simple marine ON-OFF switch, replacing the diode-based isolator.  Alternator B+, chassis battery and sense wire to one lug and house battery to the other.  Very KISS theory. And gives you many options in terms of battery combine, whether to charge the house bank while driving, etc.


Have never had to use it, but it's nice to know we could!
1993 U-240 "La Villa Grande"..CAT 3116 w/ Pacbrake PRXB...Allison 3060 6-speed..
Previous: 1983 Airstream 310 turbo diesel, 1979 Airstream 280 turbo diesel
                                      Build # 4297
                                      PNW natives
                      Home base:  'Cactus Hug' (Ajo, Arizona)
                        DW Judy & Chet the wonder dog
                        Full-Timers 'Sailing the asphalt sea'

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #10 –
Quote from: wolfe10 –
Pierce,

Yes, there are some ways that improper wiring could cause high voltage, but not if  alternator B+, chassis battery, house battery and sense wire are all joined together. Most high voltage situations have to do with  resistance on sense wire (artificially telling the alternator that it senses lower than actual voltage at the battery).

Heck, on a charter sailboat many years ago, I used a bolt and nut to connect both battery banks and alternator B+ together for charging.  Disconnected and put hot ends in old pieces of rubber hose when not charging so no dead shorts. Did this for 3 weeks in the out islands of the Bahamas, as no parts were available.

Have also wired our Foretravel with a simple marine ON-OFF switch, replacing the diode-based isolator.  Alternator B+, chassis battery and sense wire to one lug and house battery to the other.  Very KISS theory. And gives you many options in terms of battery combine, whether to charge the house bank while driving, etc.
OK, Brett, you almost have me "onboard". :-) Is the extra DUVAC terminal the only difference between our alternators and "normal" alternators? Our higher voltage could have been related to the incorrect isolator wiring coupled with the fact that one bank of batteries was bad when we started home after buying it. After installing new batteries and correcting the isolator wiring, the voltage was down to the normal range.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)
 

Re: installing Cole-Hersee  #48160 3 post isolator

Reply #11 –
Ya, anything that gives the sense terminal of the alternator a falsely low reading will result in high voltage. Resistance in connections, loose connections on the sense wire, bad cell in battery bank that sense wire is connected to, etc.

Said another way, the  alternator is only as smart as the information it receives via the sense wire.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020