Author Topic: Is Big Boy relay supposed to hum? Question on Cruise Control  (Read 2967 times)

Mike Shumack

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Is Big Boy relay supposed to hum? Question on Cruise Control
« on: November 17, 2018, 04:03:06 PM »
I'm doing a few repairs/tasks on the Coach this week and came up with two questions.

Previously my Cruise Control was not working. Pressing the Set or Resume (cruise control) button did not raise speed and in Aladdin the Cruise Control always showed OFF.
So I started troubleshooting with the SmartWheel manual. I found a loose connection on the J1 connector. With that repaired, I can now raise engine idle speed with the Set or Resume buttons.

Question 1: On the Aladdin display > Engine/Trans Status shows "Cruise Off". However since I can raise the idle now, the Cruise must be on. Is it normal for cruise to show OFF when the coach is not moving or should it show On whenever the steering wheel button is pressed On?  Maybe I have more troubleshooting to do.

Question 2: With the engine off, and coach plugged into shore power (20A) i am hearing a (pretty loud) high-pitched humming coming from the Big Boy solenoid. Is this normal?

Thanks.

Lee Welbanks

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #1 on: November 17, 2018, 09:13:15 PM »
Mike, I'm going to fire up the PT later to day or in the morning so I'll see what mine reads on or off.
My Big Boy hardly makes any noise at all, you can hear a faint hum but not much. Have you rebuilt that relay? The contacts may be corroded causing them the chatter.
I'll let you know what my aladdin  shows.

Jerry Carr

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #2 on: November 17, 2018, 09:56:18 PM »
on our 06 PT we did often hear a hum
Regards,
Jerry Carr
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Lee Welbanks

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #3 on: November 18, 2018, 06:03:59 PM »
Mike,
Fired up the coach this morning and with the rpm's set up on the cruise the Aladdin reads cruise off.
My big boy hums just a little, 10 ft away you cannot hear it.

Mike Shumack

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #4 on: November 18, 2018, 06:10:11 PM »
Thanks Lee. It sounds like my equipment is functioning normally.

Scott Shearer

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #5 on: November 18, 2018, 07:07:17 PM »
2006 Thunder

Our Aladdin display will show cruise speed 0.0 and “Cruise Off” until after the cruise control is initially engaged (at hi-way speed), it will then indicate the cruise speed setting and “Cruise On” (even if the cruise is disengaged).

Our Big Boy also hums, always has, even after rebuilding.

Scott & Susie Shearer
2006 Patriot Thunder
Lexington IV 40'
Cat C13
2015 JKU Hard Rock

Stan Simpson

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #6 on: November 18, 2018, 07:23:51 PM »
2006 Thunder
Our Big Boy also hums, always has, even after rebuilding.

Our Big Boy has never hummed, apparently it knows the words.  ::)
Stan Simpson & Becky Glover & Moe the cat
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C9 400 Cat
Honda CRV toad

Lee Welbanks

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #7 on: November 18, 2018, 10:17:22 PM »
Thanks Lee. It sounds like my equipment is functioning normally.

Mike, Its anybody's guess what is normal operation with these coaches. I don't think there are two built the same to many moving parts.

Mike Shumack

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #8 on: November 19, 2018, 05:12:13 PM »
I got a call back to my question submitted to Intellitec. M&M RV Electronics called me - they said the hum is normal. It's from the pulsing of the hold-in coil.

He also said to check the voltage drop across the main terminal lugs. If the drop is over 0.1V then the Big Boy is bad.

Bill Lampkin

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Re: Is Big Boy relay supposed to hum? Question on Cruise Control
« Reply #9 on: November 19, 2018, 05:40:19 PM »
Mike, Might be worth it to just take the  Big Boy out and clean the contacts inside. Simple solenoid, just like on a starter motor. Nice article and photos on the headlight replacement!
2005 Patriot Thunder Lexington, 3 slides
40' tag axle (short wheelbase)
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