RT-524 cooling fan running issue...

Want to put radios in your jeep? Discuss it here.

Moderators: rickf, raymond, Mr. Recovery

Post Reply
mike_v
Sergeant
Sergeant
Posts: 90
Joined: January 20th, 2020, 2:16 am
Location: Culleoka, TN

RT-524 cooling fan running issue...

Unread post by mike_v » March 5th, 2020, 4:56 am

Hi All,

New guy here and have a M151A2 with a RT-524 and a R-442A setup w/ remote speaker and proper antennas.

I have a couple issues and read every RT-524 post and went thru all 7 pages of threads

On the RT-524, the cooling fan starts up when I power up the unit and stays running without keying the mic. Tried high power and fan stays on. When I key the mic, I hear a "click" in the speaker(s) but the amber "call" bulb does not light up. Same issue with the amber "call" bulb on the R-442A. The bulbs work and I made sure both units were on the same freq. as well as the antenna. Also tried two mics and one opened up (NOS - in the bag) for the test - no difference.

A friend of mine will be looking at these units later. He said clean mic jacks, connections, switch mics, etc. He said the fan staying on is not a good thing.

Any ideas anyone?
1974 M151A2 w/ ROPS, heater, radios and M416 trailer

1986 M925 w/w 5 ton

2x M1008 CUCVs
3x M1009 CUCVs + 1x CUCV II
1x M1010 + 1x M1031 CUCV

1990 M101A2 .75 ton trailer (Kasel)
1992 M101A3 .75 ton trailer (Kasel)
1992 M149A2 "Water Buffalo" (Aero)
1995 M105A3 1.5 ton trailer (Pribbs)
2005 M1082 LMTV 2.5 ton trailer (Stewart & Stevenson)

User avatar
D Pizzoferrato
Master Sergeant
Master Sergeant
Posts: 342
Joined: May 1st, 2010, 8:16 am

Re: RT-524 cooling fan running issue...

Unread post by D Pizzoferrato » March 5th, 2020, 9:26 am

I can't answer as to the technical part of your question but can add that the fans are designed to power on when there is an overheat situation. It was discovered that the canvas covers contributed to trapping heat in and around the radio unit, while parked, causing battery rundown and possibly a fire hazard. At some point, a directive was issued that ordered the covers no longer be used. This was shared with me years ago by a well known mil radio guru.
Visit our Website! www.odcloth.com for your Canvas needs

Visit our AM151A2 restoration page http://www.odcloth.com/mymutt/1979am151a2.html

Visit our PBR Restoration Site. http://www.pbr6927.com

User avatar
rickf
General
General
Posts: 19740
Joined: November 26th, 2007, 1:28 pm
Location: Pemberton, NJ.

Re: RT-524 cooling fan running issue...

Unread post by rickf » March 5th, 2020, 12:32 pm

Do you know for a fact that these radios were not demilled? It is possible that there could be cut and/or loose wires in the case shorting out.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

mike_v
Sergeant
Sergeant
Posts: 90
Joined: January 20th, 2020, 2:16 am
Location: Culleoka, TN

Re: RT-524 cooling fan running issue...

Unread post by mike_v » March 5th, 2020, 8:28 pm

rickf wrote:
March 5th, 2020, 12:32 pm
Do you know for a fact that these radios were not demilled? It is possible that there could be cut and/or loose wires in the case shorting out.
No Rick, haven't pulled the covers off yet.

I'm insulating the new house and bouncing between the jeep and the house... :?
1974 M151A2 w/ ROPS, heater, radios and M416 trailer

1986 M925 w/w 5 ton

2x M1008 CUCVs
3x M1009 CUCVs + 1x CUCV II
1x M1010 + 1x M1031 CUCV

1990 M101A2 .75 ton trailer (Kasel)
1992 M101A3 .75 ton trailer (Kasel)
1992 M149A2 "Water Buffalo" (Aero)
1995 M105A3 1.5 ton trailer (Pribbs)
2005 M1082 LMTV 2.5 ton trailer (Stewart & Stevenson)

mike_v
Sergeant
Sergeant
Posts: 90
Joined: January 20th, 2020, 2:16 am
Location: Culleoka, TN

Re: RT-524 cooling fan running issue...

Unread post by mike_v » March 5th, 2020, 8:36 pm

D Pizzoferrato wrote:
March 5th, 2020, 9:26 am
I can't answer as to the technical part of your question but can add that the fans are designed to power on when there is an overheat situation. It was discovered that the canvas covers contributed to trapping heat in and around the radio unit, while parked, causing battery rundown and possibly a fire hazard. At some point, a directive was issued that ordered the covers no longer be used. This was shared with me years ago by a well known mil radio guru.
Hi David,

I bought seat covers from you and Donna last year - put one on (driver side backrest - 1986 M925 5 ton) and it looks great, just another one of my projects on hold till I get the new house built...

I did read about radio over-heating before, but I'm just looking for a "dust cover" that fits well - so far, no joy...
1974 M151A2 w/ ROPS, heater, radios and M416 trailer

1986 M925 w/w 5 ton

2x M1008 CUCVs
3x M1009 CUCVs + 1x CUCV II
1x M1010 + 1x M1031 CUCV

1990 M101A2 .75 ton trailer (Kasel)
1992 M101A3 .75 ton trailer (Kasel)
1992 M149A2 "Water Buffalo" (Aero)
1995 M105A3 1.5 ton trailer (Pribbs)
2005 M1082 LMTV 2.5 ton trailer (Stewart & Stevenson)

Post Reply