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Topic: Erratic Retarder Temperature Reading (Read 803 times) previous topic - next topic

Erratic Retarder Temperature Reading

Sometimes at start, sometimes at finish (obviously with engine still running) the needle of the retarder temperature gauge will pug all on (400 deg).
I know that the reading can't be correct  so I continue on.
How that I think about it, the transmission is probably in Neutral (I'll have to check that next time it happens).

High on the list of suggestions will be to check the electrical connections.
There is no play at the instrument.
Where is the connection to the Retarder temp probe?

Anything else short of a trip to Allison, which might happen it doesn't settle back to normal some time?

Other than that, we are just about finished with our move into our new (to us) house out in the country east of Georgetown, TX.
Give me a shout if you need an overnight.
Elliott & Mary Bray
ex. 1996 36' U295 - Build 4879
ex. 2018 Coachmen Leprechaun 319MB
 

Re: Erratic Retarder Temperature Reading

Reply #1 –
Elliott,

If you are talking about the gage on the dash it is fed off the sensor that is in the piping coming off the trans just below the driveshaft. If you loose this connection the gage will go to full hot. The first 2 pics. show this temp sensor. 

The external retarder temp sensor is mounted to the side of the trans retarder housing at 3 o'clock on the drivers side of the trans. The other 2 pics. show this sensor (the stainless piece held in place with the finger clip). It has 2 wires feeding it and a real good connector that can be difficult to get apart if it doesn't have some lube on it's sealing area.

Pamela & Mike

Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Erratic Retarder Temperature Reading

Reply #2 –
One hour and 45 minutes, answers and photos, wow, you have to love this forum.  Thanks Mike!!!! for sharing this info with us all.
Dave Cobb
Buckhorn Lake Resort The Club, #6202, Kerrville TX
check the map.  I do rent it out when I am traveling!
2001, U320, 36' #5887, in Kerrville, FT Club #17006, (7/23 to present)
2024 Jeep Grand Cherokee L, Summit, white
EX: 98 U295, 36' #5219, (mid door), (4/13-10/23)
EX: 93 U225, 36' (4/11 to 4/13)

Re: Erratic Retarder Temperature Reading

Reply #3 –
Dave,

With it being 19 deg. this A/M we had to let it get above 20 so my hands would work the camera. :)) :))

Hope all is well with you & Dolly.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Erratic Retarder Temperature Reading

Reply #4 –
Quote from: Pamela & Mike –
If you are talking about the gage on the dash it is fed off the sensor that is in the piping coming off the trans just below the driveshaft. If you loose this connection the gage will go to full hot. The first 2 pics. show this temp sensor. 

The external retarder temp sensor is mounted to the side of the trans retarder housing at 3 o'clock on the drivers side of the trans. The other 2 pics. show this sensor (the stainless piece held in place with the finger clip). It has 2 wires feeding it and a real good connector that can be difficult to get apart if it doesn't have some lube on it's sealing area.

(My rig is at the storage facility right now and so I can't access it to look underneath.)

Your pictures show two different temperature sensor locations. Which sensor feeds which item? I know on our rig that the dash gauge is driven by the sensor at the output of the retarder, because it shows a very fast temperature rise when the retarder is activated. My Silverleaf VMSpc is driven by a different sensor, because it shows a very slow temperature increase when the retarder is activated.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Erratic Retarder Temperature Reading

Reply #5 –
David,

First 2 pics are the sensor that is for the gage on the dash #4624 & 4625

Second 2 are of the external retarder temp sensor. #4627 & 4628

With yours being a '95 it may be in a different location.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Erratic Retarder Temperature Reading

Reply #6 –
Quote from: Pamela & Mike –
First 2 pics are the sensor that is for the gage on the dash #4624 & 4625

Second 2 are of the external retarder temp sensor. #4627 & 4628

With yours being a '95 it may be in a different location.

Thanks, but I have another question: Does your dash gauge rise very quickly when the retarder is engaged (while going down a steep hill, for example)?
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Erratic Retarder Temperature Reading

Reply #7 –
Quote from: D.J. Osborn –
Thanks, but I have another question: Does your dash gauge rise very quickly when the retarder is engaged (while going down a steep hill, for example)?

My 97's does not as a comparison
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Erratic Retarder Temperature Reading

Reply #8 –
Quote from: Caflashbob –
My 97's does not as a comparison

Thanks. As I indicated earlier, on our '95 the dash gauge appears to read the retarder temperature, while the VMSpc appears to read the sump temperature. It is interesting (and I believe useful) to compare the two.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Erratic Retarder Temperature Reading

Reply #9 –
Quote from: D.J. Osborn –
Thanks. As I indicated earlier, on our '95 the dash gauge appears to read the retarder temperature, while the VMSpc appears to read the sump temperature. It is interesting (and I believe useful) to compare the two.

Probably made every owner panic to see the gauge move so quickly.  Bet they swapped out the sensor wiring....
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Erratic Retarder Temperature Reading

Reply #10 –
Quote from: Caflashbob –
Probably made every owner panic to see the gauge move so quickly.  Bet they swapped out the sensor wiring....

Agree. It's definitely exciting to watch it rise and to see the red light come on, and then it's reassuring to see the VMSpc readout.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Erratic Retarder Temperature Reading

Reply #11 –
David,

With you having a '95 do you have a mechanical engine. If so your trans. talks differently to your dash than an electronic engine. I know that we are talking transmissions but how the transmission ECM works depends on the engine type.

Oh our dash gage does raise slowly.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Erratic Retarder Temperature Reading

Reply #12 –
Quote from: Pamela & Mike –
With you having a '95 do you have a mechanical engine. If so your trans. talks differently to your dash than an electronic engine. I know that we are talking transmissions but how the transmission ECM works depends on the engine type.

Oh our dash gage does raise slowly.

Our '95 has the electronic M11 and the HD4060MH transmission. The engine sends a variety of information to the VMSpc. It's quite interesting to compare the two temperature readings. The two agree well until the retarder is activated. When it's activated the dash gauge rises quickly, while the VMSpc reading slowly increases. The dash gauge falls quickly when the retarder is deactivated, and then the two again agree.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Erratic Retarder Temperature Reading

Reply #13 –
With you having a M11 celectric then I would have to agree with Bob. After several people panicked they changed the pickup for the dash gage.

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Erratic Retarder Temperature Reading

Reply #14 –
Quote from: Pamela & Mike –
With you having a M11 celectric then I would have to agree with Bob. After several people panicked they changed the pickup for the dash gage.

It certainly appears as if he could be correct. Thanks for all of our information and the pictures!
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186

Re: Erratic Retarder Temperature Reading

Reply #15 –
David,

Just out of curiosity when you get out to your coach look and see if yours has the same sensor on the same hose fitting that is in the pic. #4624 or 4625 (same hose & sensor just  1 close up, 1 futher away)

Pamela & Mike
Pamela & Mike 97 U 320

"It's not what happens to you, but how you react to it that matters."

Re: Erratic Retarder Temperature Reading

Reply #16 –
Quote from: Pamela & Mike –
Just out of curiosity when you get out to your coach look and see if yours has the same sensor on the same hose fitting that is in the pic. #4624 or 4625 (same hose & sensor just  1 close up, 1 futher away)

Will do.
David and Carolyn Osborn
1995 U320C SE 40' Build 4726 Feb 1995
FMCA 147762
Motorcade 17186
 

Re: Erratic Retarder Temperature Reading

Reply #17 –
While I have talked via OP with the mechanic of the family (Pamela and Mike), I would be remiss to not thank them in front of all the Forum.
Less than 2 hours after my post I had the straight scoop, pictures and  all.

Thanks
Elliott & Mary Bray
ex. 1996 36' U295 - Build 4879
ex. 2018 Coachmen Leprechaun 319MB