My Alternator is connected to... This?

[drfw]

My understanding is that my 12si alternator has an internal regulator.
So, what the heck is this thing?
It is mounted on the alternator bracket.
Any info on connectivity appreciated!
Pic's attached.
Thanks!

[ronstory]

drfw--

Are you sure it's a Delco 12si (or clone)? I've seen a lot of them, clocked all different ways... but never with that connector.

[Andrew Selking]

That is the blower relay. It has nothing to do with alternator . It might be mounted by or near the alternator . I have replace many over the years working on cars and trucks.

[guy99]

I have one of those which is actually my starter relay.

[overlander63]

It is a multipurpose relay. In this case, it could engage when you energize it, and route some of the alternator's output to the house batteries. If used in that manner, it would be a crude, but effective, isoltion switch.

[drfw]

I did a bit of wire tracing.
Looks like she goes to the starter among other things.
must be a starter relay.

how does it work?
IE:
alternator/Batt parallel connected as big juice to output when triggered?
ignition switch start postion juice as input trigger?
Big juice output to starter solenoid?

There is a fourth wire that may go to the coil or something.

[drfw]

OK
I believe I have the answer.

This relay is known in the biz as a "hot start" relay.

They are commonly used in GM starter applications to feed a nice big flow of current to the (super hungry when hot) solenoid/starter.

please find connectivity explanation link below.

http://www.type2.com/bartnik/images/relay.gif


Lots of cats are using the old ford type bypass solenoids to fix the hot start issue.
Please see the link below.
(It's a link to an online catalog, but it has a well written explanation for the application.)

Catalog


Best to all of you.

[ronstory]

drfw--

Glad to hear to worked out.

[drfw]

Please note:
Airstream originally wired the genny's 12v feed directly to the engine starter.

Unfortunately, using the old ford type bypass solenoid as a hot start fix will kill 12v power to your genny, unless you rewire the genny 12v feed to somewhere other than the starter.