Community Forums

rag_ftw · 03-15-2016, 10:59 AM

Dan, if I only have two small terminals is it possible to change to a 3 terminal latching relay? If so what should be done?

Tireman9 · 03-17-2016, 01:16 PM

Hi folks, sorry for not keeping up with the posts. Had sick cat then drove 832 miles in two days to Perry GA to FMCA convention.

I tried to trace the reason for amp drain but was not able to find a single source. Until I happened to turn the battery disconnect switch to the on position than the 2 amp drain went away.

I have seminars to give here in Perry so don't have time to really dig into the issue but still want to understand what is happening.

I will try and post detailed list of actions and test results but may have to wait toll I get home next Tuesday.

BFlinn181 · 03-17-2016, 01:37 PM

Sounds like cycling the switch temporarily 'fixed' the drain. I'd suspect the switch that triggers the solenoid isn't opening after you've depressed it. You'll have to get it to show the 2 amp drain, then disconnect the wires to the switch and see if it goes away.

dpinvidic · 03-17-2016, 07:25 PM

Quote:

Originally Posted by rag_ftw

Dan, if I only have two small terminals is it possible to change to a 3 terminal latching relay? If so what should be done?

Lets make sure that you don't already have one.
While looking around, I found this one....it is a laltching relay, but only has two control terminals.
Cole-Hersee Relay.

You need to check that with your relay in BOTH the on and off position, there is no voltage on the coil (small terminals).

If you find that you have a regular continuous duty solenoid, all you need to do in order to use the one I posted is to replace your switch with a momentary switch.
Each time you momentarily apply power, the relay will toggle to the other state.

First I must ask why you want to swap it out...what is the reason??

Dan

rag_ftw · 03-18-2016, 12:43 PM

Quote:

Originally Posted by dpinvidic

Lets make sure that you don't already have one.
While looking around, I found this one....it is a laltching relay, but only has two control terminals.
Cole-Hersee Relay.

You need to check that with your relay in BOTH the on and off position, there is no voltage on the coil (small terminals).
Well, I can't check for power currently. Turned the salesman switch to the off position last night and the relay will not power up today with the switch! I can short across the main power in wire and the relay power small terminal and the relay will click, I get power to the coach and the relay starts warming up. When i short across the main power and main ground wire I get power to the coach, the relay does not click, nor does it heat up. I do know that anytime the salesman switch is on and the coach has power through the relay it is hot to the touch.

If you find that you have a regular continuous duty solenoid, all you need to do in order to use the one I posted is to replace your switch with a momentary switch.
Each time you momentarily apply power, the relay will toggle to the other state.

First I must ask why you want to swap it out...what is the reason??
I want to eliminate the constant 1 amp draw of this relay anytime I have the salesman switch on and the coach has power.
Dan

If I wire around the relay to get power do I run the risk of tieing the coach and chassis batteries together? If the only thing wiring around the relay does is eliminate the salesman switch I may just do that as I never use the salesman switch.

dpinvidic · 03-19-2016, 08:30 AM

Quote:

Originally Posted by rag_ftw

If I wire around the relay to get power do I run the risk of tieing the coach and chassis batteries together? If the only thing wiring around the relay does is eliminate the salesman switch I may just do that as I never use the salesman switch.

Now this all makes sense. I had thought you were talking about battery disconnect relays.

The salesman switch is a small switch with a low current rating. Therefore it needs a relay in order to control a larger smount of current.

Personally I don't like making unusual changes to a vehicle, but you can easily accomplish what you are trying to do.

Simply move both large wires to the same terminal on the relay. This give the coach power continuously.
Then disconnect one of the small wires from the relay and tape the end to prevent a short. This keeps the relay from activating.

Now your salesman switch does nothing, but the next owner will think it is broken.

Regards,

Dan

rag_ftw · 03-19-2016, 08:52 AM

Quote:

Originally Posted by dpinvidic

...The salesman switch is a small switch with a low current rating. Therefore it needs a relay in order to control a larger amount of current....

Therein lies the problem. That relay being energized all the time pulls around 1.4 amps from my coach batteries. If the only purpose it serves is to power off/on those few systems controlled by the salesman switch I think I will wire around it which will serve two purposes. That will eliminate the constant 1.4 amp draw and I won't have to buy a new relay every couple of years because the old one died from having power constantly applied to it.

I had been told in the past that wiring around this relay would permanently connect the coach and chassis batteries, thus eliminating any isolation. I am thinking both sets of batteries are only connected when the battery boost relay is activated and the salesman switch relay has no effect on the chassis batteries. Can you confirm my logic? (Has it become obvious yet that I am more of a mechanical than electrical person?!!)

dpinvidic · 03-20-2016, 09:45 AM

Quote:

Originally Posted by rag_ftw

Therein lies the problem. That relay being energized all the time pulls around 1.4 amps from my coach batteries. If the only purpose it serves is to power off/on those few systems controlled by the salesman switch I think I will wire around it which will serve two purposes. That will eliminate the constant 1.4 amp draw and I won't have to buy a new relay every couple of years because the old one died from having power constantly applied to it.

I had been told in the past that wiring around this relay would permanently connect the coach and chassis batteries, thus eliminating any isolation. I am thinking both sets of batteries are only connected when the battery boost relay is activated and the salesman switch relay has no effect on the chassis batteries. Can you confirm my logic? (Has it become obvious yet that I am more of a mechanical than electrical person?!!)

You are right. Most people don't know about this relay and assume you were talking about the Aux Start relay (yes, that one ties the batteties together).

Put a pices of tape on the relay that says "bypassed, relay is good" incase I buy your coach in a few years....

Dan