Replacement part help

[Gusshr]

Hi Everyone. One of the delcoremy relays that, when the engine oil pressure goes up it closes the circuit to deliver 32v to the voltage regulator so that the alternator would start producing voltage, is not functioning. Anyone knows of any replacement? Anyone knows how many amps are delivered through this relay to the voltage regulator? I am trying not to change the connector by buying an exact replacement but I don’t know the part number and nothing is written on the box. I can get a replacement but I need to know the Amp rating. Any one knows? Thanks for your help.

 

[Captain Ralph]

There is not much of an amp rating. It is just a sense lead offering feed back to the regulator.
Low or no resistance is of importance here.
Any N/O Hobbs or Nason switch will do fine.
I'm using the same system on my alternators.

 

[Gusshr]

There is not much of an amp rating. It is just a sense lead offering feed back to the regulator.Low or no resistance is of importance here.Any N/O Hobbs or Nason switch will do fine.I'm using the same system on my alternators.

Thank you for your reply. For some odd reason the current coming from the oil pressure switch excites a 32 V relay and in turns activates another 32 V side of the relay to send Power to the voltage regulator. That is how Hatteras had it in the original blueprints that I have with the vessel. The switch is working fine however the relay is the bad part that I have. In factI don’t even know why we have a relay when I probably can use the same 32 V coming from the oil pressure switch directly to feed the voltage regulator. I’m thinking the only reason is that the voltage regulator may require higher amperage than the switch can’t tolerate, although it doesn’t look that way from the size of the original wires. Any case so my question was about replacing the relay and not the pressure switch.

 

[Captain Ralph]

I think the theory in your design; shorter wires with the relay; less chance of a voltage drop.
If it is a large relay, maybe larger contacts was meant for less resistance when closed.
Were talking milliamps in current on the feedback line.

If you have a 32v system, the alternator is to charge near 38v.
If the resistance in the feedback wire only gives the vr 37v, the alternator will put out a higher voltage to make that feedback lead read 38, then your battery gets over charged at 39v.
If the 32v coming off of the oil pressure switch is there by way of the key switch and breaker panel, it may have already lost a half volt or so.


The feedback helps the first excitement (turn on) and gives the vr a level to charge. Ideal when a diode battery idolator is used like on our rig.

Is it a Delco or Ford style relay? Picture?
It my have a fuse somewhere also.

And Sam's may have the part on their shelf, or even offer you the vendor part number.

 

[Bob Bradley]

Gawd I love this place. You can bet you wouldn't get advice like this on, say, the Ocean owners site.

 

[Gusshr]

I think the theory in your design; shorter wires with the relay; less chance of a voltage drop.If it is a large relay, maybe larger contacts was meant for less resistance when closed.Were talking milliamps in current on the feedback line.If you have a 32v system, the alternator is to charge near 38v.If the resistance in the feedback wire only gives the vr 37v, the alternator will put out a higher voltage to make that feedback lead read 38, then your battery gets over charged at 39v.If the 32v coming off of the oil pressure switch is there by way of the key switch and breaker panel, it may have already lost a half volt or so.The feedback helps the first excitement (turn on) and gives the vr a level to charge. Ideal when a diode battery idolator is used like on our rig.Is it a Delco or Ford style relay? Picture?It my have a fuse somewhere also.And Sam's may have the part on their shelf, or even offer you the vendor part number.

Amazing analysis thanks a lot. I have attached a picture of the nonworking Relay which is DelcoRemy. I purchased a 36 V relay that I intend to replace it with. I really is a relay and I don’t think I could go wrong with using a generic one. What are your thoughts? I’m almost ready to cut the old wires down to install new fittings on them.

 

[Captain Ralph]

Please let us know how the 36V relay works out.
I can imagine a low battery (less than 32v) after cranking may not pull the contacts closed, thus not enabling the alternator, to recharge the now low batteries.

The spec voltage is to make the contacts close, most any (in reason) voltage can go thru the contacts.

 

[KPTIM]

That relay is a field control relay.
he relay is still available.
There is a one new one on eBay for $19.
Also available on Amazon.

https://www.ebay.com/itm/32-Volt-Re...e-Application-Delco-nos-1115843-/143531309474

Also just do a search on Delco 32 volt field relay.

 

[Gusshr]

That relay is a field control relay.he relay is still available.There is a one new one on eBay for $19.Also available on Amazon.https://www.ebay.com/itm/32-Volt-Re...e-Application-Delco-nos-1115843-/143531309474Also just do a search on Delco 32 volt field relay.

Oh great! I just walked back from the boat installing the 36v relay and just saw your post. The good news is that the one I installed is working fine. I don’t know what to do now??!!

 

[Captain Ralph]

Oh great! I just walked back from the boat installing the 36v relay and just saw your post. The good news is that the one I installed is working fine. I don’t know what to do now??!!

Run the batteries down and try again.
I still would get the correct part. Cheap insurance.

You don't want " on a dark and stormy night " My batteries would not charge..

 

[Gusshr]

Run the batteries down and try again.
I still would get the correct part. Cheap insurance.

You don't want " on a dark and stormy night " My batteries would not charge..

Already cut the cables and created new connections. So just ordered the 32v one on Ebay. I guess I will be cutting the cables and putting new connectors again.

 

[Captain Ralph]

In your picture; is that a solid state or still mechanical contact relay?

New tinned copper wire and shrink butt ends & ring terminals. You want the lowest resistance from the battery to the VR.