relays, relays

[JohnLori]

Can someone tell me what these relays are for? They are inboard of the last passenger-side compartment, the one with the oil check, etc. It's always good to know where things are when they go bad.


This one is on the back of the aft wall of the battery compartment, above the back of the chassis 12V disconnect. Note that this is not in the back of the battery compartment, i.e. it is not the battery charge connect relay, but it is on the other side of the bulkhead to the left as you look in the battery compartment.



These are in the vicinity of the air cleaner and air drier, attached to the frame. This photo is from the ground, looking up. It sits low in the compartment.



Same thing, only from the forward end looking aft. For perspective, you can see the ground and mud flap at the bottom of the picture.



Same, but more from the top, looking aft.

[JLMunsil]

My guess is that the first one is for the starter, and the others are for the grid heaters for engine start up.

[EngineerMike]

I think JL is right, i.e. the metal can solenoid is the relay to the starter relay (yes, two in series; if you follow the ~#12 or #10 wire out of the fat stud series toward the motor, it should end at the starter motor's bendix type solenoid.
Second photo is actually a pair of auto-resetting breakers, 3rd photo shows the hop from breaker to solenoid (or relay), and if you follow those toward the motor they should end at the intake air heaters for cold weather starting.

[Algoma]

On the early Alpines these relays were all together and even labeled! Perhaps the photo will help you identify some of yours.

[JohnLori]

Thanks Jim, Mike and John. A picture really is worth a thousand words. Now at least I know what all that stuff is. I still haven't located the fuel solenoid. I'll look again. As far as the starter solenoid--it takes a solenoid to close another solenoid that allows current to the starter motor? I like John's arrangement, where it's all together and labeled.

[EngineerMike]

The starter circuit is very high amp, so it is better to ramp up w/the solenoid/solenoid than to use a super-fatboy (obese-boy solenoid?) that can take the whole starter current. Vansco outputs are only good for 6 or 12A depending. That silver solenoid is probably rated for 75A but only switching 20A or so, and should last for the duration which is good automotive design. (he said)