My hydraulic slide sometimes stops on retraction. After a few minutes, it will start again and work. While I was checking voltages on the two hydraulic motor relays I found that the continuous duty relay is "on" as long as my key is on. Realy gets hot to touch (215 d.) Anyone know why this relay is "on" all the time even while traveling and not being used to activate slides or jacks? And should it get hot enough to burn your skin? It's an HWH hydraulic system.

is the pump running ?are you sure that is a pump relay ?where is it located ? at the pump or someplace else ?could it be the battery combiner relay ?i am not familiar with your electrical layout ?but the only relay i am aware of that stays on all the time the key is on, is the battery combiner relay

What is the model of your system? It could be a bad circuit board.

MrWizard wrote:is the pump running ? - YESare you sure that is a pump relay ? - YESwhere is it located ? at the pump or someplace else ? - one on each side of pump. could it be the battery combiner relay ? - Not sure Tiffing service called them relays - one continuous and one ntermittenti am not familiar with your electrical layout ?but the only relay i am aware of that stays on all the time the key is on, is the battery combiner relay - Tiffin did not know why (the continuous relay stayed on when key is on ) either, why that is necessary. Called HWH factory service - Will ask about combiner. HWH is one week behind answering phone service requests. 10/6/17

1. YES, the primary relay is closed(ON)when the key is ON.2. Never checked before about how hot they get3. That relay is ON with the Key, because Tiffin slides operate with the KEY ON. So, for the pump motor solenoid to activate from the slide switch, the primary solenoid must be ON to transmit battery power to the motor solenoid4. The solenoids are not that expensive. I would replace it and then see.5. Are you the original owner? Maybe someone replaced the continuous duty solenoid with an aftermarket that does not have the same rating as the HWH solenoid DougPS Tiffin rarely knows how any Non Tiffin appliance worksE MAIL HWH! You will get a response in less than 2 days.

enblethen wrote:What is the model of your system? It could be a bad circuit board.Just had the main board replaced. Unit was not leveling. Unitl levels fine now. It stops on retraction. After 8-10 min. It then retracts fine. Slide has been adjusted and balanced. Slide go in and out evenly and with no strain. Same speed both ways.system HWH 750. Jack/slide combination.

HWH hydraulic relay | Good Sam Community

enblethen
Nomad
Oct 07, 2017
That is not sound engineering.
wtravlr1
Explorer
Oct 07, 2017
enblethen wrote:
It seems to be odd that the main relay is energized all the time the ignition switch is in the "on" position.

I think so, Tiffin said that's how they were, but I'm not sure that is right. HWH is still a week out on a return phone call to find out. will post when I get an answer.
enblethen
Nomad
Oct 07, 2017
I would be thinking about adding a manual switch in the control circuit.
A lit rocker switch of about 15 amp rating.
wtravlr1
Explorer
Oct 07, 2017
enblethen wrote:
I would be thinking about adding a manual switch in the control circuit.
A lit rocker switch of about 15 amp rating.

That's where I am headed, need to talk to HWH factory to see if there is any downside. I think it should have a way to cut power. Don't see why it is hot all the time I am driving. I think a lot of coaches have an on/off for the slide then the slide operation switch.

Still wondering why the slide outs stop and then restart after short rest.
enblethen
Nomad
Oct 07, 2017
On my HWH system there is an on/off switch (button) on the control. Once ignition is shut off you must push the on button to do anything further.
I did not find the 750 model on their website.
dougrainer
Nomad
Oct 07, 2017
https://www.hwhcorp.com/ml48380.pdf

Well to put in in perspective. I have 38 years and still working on Tiffins. I have over 32 years working on HWH and have factory training at both. The system has 2 solenoids. The first solenoid just activates the system. NO real draw. It should NOT get hot just from travel. I assume the OP is stating that when he is operating the slides and/or the jacks that is when he finds that solenoid hot. IF so, then the solenoid needs replaced. I have not checked and never had too, but the system "may" de-energize when the Parking brake is released, as the jacks and slide rooms will not function on a Tiffin (or other motorhome)when the parking brake is NOT engaged. So, that would stop any concerns about the having that solenoid on. BUT, on some systems(300 series) the solenoid does stay energized when the brake is released to allow the system to go into hibernation for auto retract from road heat. HWH has built hundreds of thousands of these systems and I doubt it is a BAD ENGINEERING design. Tiffin just installs the system. The parameters are HWH parameters, NOT TIFFIN. Doug
MrWizard
Moderator
Oct 07, 2017
in another thread, poster having trouble with jacks signaling down while driving, but they are retracted

it was noted that there is a retract feature that checks fluid level and auto retracts when level is low, meaning a jack not fully retracted

just maybe the powered on relay/solenoid is there so the system is 'alert' and ready to respond

and like Doug says, if it gets physically hot just being energized, then it needs to be replaced
enblethen
Nomad
Oct 07, 2017
There is a reason it gets hot.
It could be current flow through the main contacts or higher resistance on the coil. Continuous duty coils should not get the housing hot.
wtravlr1
Explorer
Oct 08, 2017
dougrainer wrote:
https://www.hwhcorp.com/ml48380.pdf

Well to put in in perspective. I have 38 years and still working on Tiffins. I have over 32 years working on HWH and have factory training at both. The system has 2 solenoids. The first solenoid just activates the system. NO real draw. It should NOT get hot just from travel. I assume the OP is stating that when he is operating the slides and/or the jacks that is when he finds that solenoid hot. IF so, then the solenoid needs replaced. I have not checked and never had too, but the system "may" de-energize when the Parking brake is released, as the jacks and slide rooms will not function on a Tiffin (or other motorhome)when the parking brake is NOT engaged. So, that would stop any concerns about the having that solenoid on. BUT, on some systems(300 series) the solenoid does stay energized when the brake is released to allow the system to go into hibernation for auto retract from road heat. HWH has built hundreds of thousands of these systems and I doubt it is a BAD ENGINEERING design. Tiffin just installs the system. The parameters are HWH parameters, NOT TIFFIN. Doug

One solenoid, i assume is the continuous duty will get hot as long as the key is on, upon ending a days drive and before using jacks or slides, the temp on the one solenoid id 215d. too hot to touch. seems to always have power to it. After operating jacks and slides, temp did not change. Solenoid only cools when key is off. Slide has been acting up. Press retract slide starts for about 2 seconds stops. Wait about 8-10 min. slide retracts normally good speed. Slide is lubed, balanced and goes in and out evenly.

1. don't know why it stops and seems to have to reset before the slide operates again - does only on retraction.
2. don't know why one solenoid is too hot to touch as long as key is on.

If you can give any thought it would be appreciated.

thanks/

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