faulty battery disconnect

[ovsa]

Seems like when i want to disconnect my coach battery , using the wall switch near the monitors, I have to trigger it a couple of times to get the solenoid (in the electrical compartment) to engage/disengage. Should i look at replacing that unit or could it be something else? Is there a better/newer version out there? Thanks 2003 Chevy 170 Pop.

[GeorgeRa]

You can take this relay apart and see if copper contacts are contaminated. Clean them well, use an emery paper, contact grease and put it together. If contacts residue was a problem, you saved yourself some expenses.

https://www.amazon.com/NO-OX-ID-Spec.../dp/B00HDF9EXE

[mkguitar]

solenoids are easily serviced ( as above)



on many designs, the contact disk is flipped over to the "clean side"


the contacts are damaged by LOW voltage making a poor incomplete contact and arcing and pitting the metal.


a poor contact will build heat = more damage and likely experience the poor "making" as you are.


the solenoid you have a is a "ford type" easily sourced


fords tend to have the starter solenoid on the firewall, GM Delco, Hitachi, most other starters have the solenoid piggyback on the starter motor


while you are in there clean up all the wire connections, and check the cables are firm, clean and dry under the insulation ( cables can rot inside the jacket and turn to a soft mush)


mike

[peteco]

Originally Posted by GeorgeRa

You can take this relay apart and see if copper contacts are contaminated. Clean them well, use an emery paper, contact grease and put it together. If contacts residue was a problem, you saved yourself some expenses.

https://www.amazon.com/NO-OX-ID-Spec.../dp/B00HDF9EXE

George,
Do you think it is worthwhile to check and clean an older relay? My unit is 15 years old with lots of use.

[avanti]

If you are inclined to spend vastly more money for vastly better quality, take a look at the Bluesea ML- series relays.

[GeorgeRa]

Originally Posted by peteco

George,
Do you think it is worthwhile to check and clean an older relay? My unit is 15 years old with lots of use.

Mine started to have problems within the first 2 years. No issues since but the van is stored inside the garage since 2015. I concluded that humidity was the culprit for the failure. The brown residue was likely a mix of cupric oxide with factory lubricant. Copper contacts were very lightly eroded and a paint thinner followed by a light abrasive was sufficient to get the relay working again.

I know 2 companies making these types of battery disconnect relays, Intellitec and Bluesea. Bluesea is better with silvered contacts but also more expensive. Both operate the same, current is only drawn during switching to on or to off, regular relays draw current in on or off state.

EDIT: Yes, if you store your van outside I would consider cleaning and lubricating contacts a preventive measure.

[GeorgeRa]

Originally Posted by avanti

If you are inclined to spend vastly more money for vastly better quality, take a look at the Bluesea ML- series relays.

Agree, silvered contacts will not cause issues. In my conversion I decided to use Intellitec having good past experience with them.

[avanti]

High current DC is pretty much the worst case for contacts. Arc time is intrinsically limited in AC, but not DC.

The only thing worse is high current/high voltage DC.

[GeorgeRa]

Originally Posted by avanti

High current DC is pretty much the worst case for contacts. Arc time is intrinsically limited in AC, but not DC.

Indeed, amazing that points lasted thousands of miles in heavy automotive demand.

I am not sure that battery disconnect relay operates in high DC currents, loads are usually off and charger, even if on, needs a few seconds to turn to high current charging. Contact surfaces in my case didn’t have much arc related pitting, it was the brown residue, likely a mix of Cu2O and hardened lubricant preventing metal to metal contact.

[Bobd254]

I'd clean the contacts on the connectors . My 2000 van had crusty contacts on the connector to the control box, and at the fuses on the relay.