- December 22, 2020 at 10:07 #47768Don GParticipant
I am having a perplexing issue with the battery isolator installed in my camper. The old one appeared to have a bad solenoid so I replaced it with one made by Blue Sea. The issue is that the house batteries are not being charged.
When the engine is on, my multimeter shows that there is voltage of 14.6 coming into the isolator, as well as 14.6 going out the battery connection side of the isolator. However, as soon as I connect the battery charging wire from the house battery to the isolator, the voltage on BOTH sides of the isolator drop to that of the house batteries, which at this point is 12.8. So presently the house batteries are not being charged by the alternator. Does anyone have any suggestions as to what may be causing this? Thanks.
- December 22, 2020 at 11:32 #47773AnonymousInactive
Based on the symptoms you’re stating, I’ll posit a guess or two:
1) Since the solenoid appears otherwise operable when not connected to the house battery, I would look elsewhere…
2) Do we know if alternator of sufficient current capacity to charge both the truck and the house batteries??…Voltage will normally drop off under a more severe load – house battery is the load, so I’ll assume a yes…
3) No mention of a failing fuse (to 7 pin power terminal) inside the under hood fuse box – fuse seems to be ok as demonstrated by the voltage drop off when solenoid is connected to house battery. Voltage drop off suggest high current.
4) Disconnect the positive battery cable to interrupt charging to the house battery…Did the solenoid output voltage then rise??…If so, this suggest that the problem does not reside in the vehicle-to-camper wiring or the 7 pin connector cord.
At this point I would begin to suspect an internal short the house battery or possibly a short in the battery cabling…
- December 22, 2020 at 11:41 #47774AnonymousInactive
Oops, upon a re-read, another possibility could be that the house battery is undercharged – this could also cause the voltage drop (current related) until the battery finally recovers…
- February 13, 2021 at 17:04 #491162Z BundokParticipant
What fixed it? Cause of issue? Could the readings be different used on the type of battery? Flooded lead, AGM, LiFePO4?
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