I need an additional fuse block for my classic car. I installed a relay as follows.
86 ground
30 power (fused from Battery)
87 positive side of coil for keyed power
85 new fuse block
this resulted in my battery going dead in a few days of the car sitting. Disconnected relay, charged battery and it was fine a week later so my relay connection is the culprit ..help, thanks

 

According to this link the coil connections are pins 85 and 86 The contact common is 30 the NO contact is 87 and the NC contact is 87a I dont see how the way you have wired it should discharge the battery but it should not work as required. I don't know if there is more than one convention for car relay pin numbering. I think 86 and 30 are correct but you have 85 and 87 swapped over.

Les.

 

Sounds like you may have the relay coil connected directly to the battery.

 

Thanks... I'll reverse 85/87 tomorrow and post results.

 

Look at the schematic on the side of the relay and check the specifications on it. If it is a standard SPDT relay commonly used, it will be connected as follows:
Pin 86 is coil positive and generally connected to a switch. Otherwise coil stays energized.
Pin 85 is coil ground.
If there is no suppression diode, these can be reversed but I always connect this way so there is no guessing.
Pin 30 is connected through a fuse to battery.
Pin87a is normally closed
Pin 87 is normally open and often connected to the load device.
Side note: One can no longer assume that all relays are the same. There are several variations available now and that is why I said to check the diagram. Cheers!

 

I need an additional fuse block for my classic car. I installed a relay as follows.

OK, so you can add something like an automotive 8, 10 or 12 way fuse block and wire it to either Accessory or Always On from the vehicle. What I don't understand is why you want to use a relay to power the added fuse block? If for some reason you want the added fuse block switched why not connect it to the Accessory line so it isn't always on. Typical automotive relay will draw about 160 mA on the coil some much less. That is not very much, even over a 7 day week if it is on 24/7. Anyway, I guess I don't understand the need for a relay when adding a fuse block?

Ron

 

OK, so you can add something like an automotive 8, 10 or 12 way fuse block and wire it to either Accessory or Always On from the vehicle. What I don't understand is why you want to use a relay to power the added fuse block? If for some reason you want the added fuse block switched why not connect it to the Accessory line so it isn't always on. Typical automotive relay will draw about 160 mA on the coil some much less. That is not very much, even over a 7 day week if it is on 24/7. Anyway, I guess I don't understand the need for a relay when adding a fuse block?

Ron

I'd venture a guess that maybe it's just possible that the anticipated added load on the electrical system will be more than what would be safe to put through the stock ignition switch without having a car full of smoke from burnt wires barrelling down the road.

 

Would this classic car be a 70 Dart with a 440 by any chance? I can remember the old man picking us up the first time after school in his 69.

 

I'd venture a guess that maybe it's just possible that the anticipated added load on the electrical system will be more than what would be safe to put through the stock ignition switch without having a car full of smoke from burnt wires barrelling down the road.

Wouldn't rule that out. Just a matter of curiosity on my part.

Ron

 

No ..my 440 70 dart was to over powered for the rear to hook up and the 440 was so heavy that when it came to a turn under power it was a hand full. Fun but unstable ride. This one has a 408 stoker engine that drives much better and is very quick.

To cold to fool with the relay . Will be 40* next week so I'll get to it then.

 

Never did check back on this. Nice ride. Too bad they didn't bring the body back when they started making darts again.
Dad did his up orange with the stripe around the back a few years back. I just remember many times being firmly planted in the seat after taking off from a stop sign as a kid.
Good luck!

 

Sorry I forgot. Reversed 85/87 and it's OK now. Thanks, Happy New Year