OTR Condenser fan motor

[phorner]

We are travelling in some very warm parts of the country and haven't had less than triple digit temperatures in a couple of weeks.

When I switched off the OTR air conditioning upon arrival at Rancho California, the condenser fan motor failed to shut off. Only way to shut it off was to use the 24V disconnect in the engine bay. I thought that hopefully, the fan motor relay was just hot and kind of "stuck".

Naturally, when we started to depart Rancho en route to Indio, the condenser fan failed to start when I switched the system on.... so no OTR for the trip to Indio

I checked the breaker (CB9) and it was OK so I felt pretty confident that the problem was the relay. After a consultation with Jon, I searched and found a pair of replacement relay's which are labeled R38 and R39 for the evaporator and condenser fan motors.

These relays are made by Prestolite and are model SAS 5401A. Prevost part # 561005.

Replaced the suspect relay and all is well

Photo shows the 2 relays....

[jelmore]

Thanks, Paul. That's certainly one to file. Though I've had my share of OTR woes lately, electrical hasn't been one of them.

Responding to all the Prevost service bashers, in the last several months, we've had the OTR serviced by two truck reefer companies and two tour bus companies. The only one that came close to knowing a lot about this system was the bus company that runs a bunch of H3s. If we had been close to Prevost, that is where it would have gone. That said, I still wouldn't trust them with them unattended and me uninformed.

[tdelorme]

Good info, Paul.. That relay box with the cover removed is located where?? In the condenser fan motor bay?

[MangoMike]

Paul,

I've found this be a common failure.

Good photo.

MIke

[phorner]

Mango,

I will now be carrying a spare! You can imagine trying to find one on a Friday afternoon at the beginning of a holiday weekend.

Ted,

Yes, the box is located in the condenser bay, just above and slightly to the right of center of the blower motor. Mine has the breakers installed in the bottom of the box. Everything was clearly labeled.

[Jon Wehrenberg]

Owners of newer Prevost chassis will not see as many of that type relay as the older shells. Our 1987 had a bunch of those relays in both 12 volt and 24 volt coils and they were used on everything from the drivers air fan to the clearance lights, to the run relay. They were all subject to failure so I continue to carry 12 and 24 volt versions in my spares even today.

The few we use in newer shells are just as failure prone so it is worth carrying them, but if needed they are usually available at large NAPA stores or WW Grainger.

[Ray Davis]

Anyone know if these are Liberty specific, or is it likely my Marathon with OTR has the same relays? Paul, what was the price on those. Seems like a spare or two is in order.

[JIM CHALOUPKA]

Ray, I was wondering the same. I thought though that if there was a Prevost part number and that with OTR being Prevost that it would not be a converter item.

I found the price from the mid $70.00s and $60.00s to a low of $12.28 from a lift truck parts supplier, by searching the net.

I am going to buy a few from them and see what the quality is. It should be fine as a lift truck is a heavy duty high use application.

The solenoid is listed by AMETEK Prestolite with a carry amp rating of 200. What I don't know is if the one from HGMliftparts has the same rating.

http://store.hgmforkliftparts.com/PL...A-P786795.aspx

[phorner]

The price from Prevost Parts was $52.12 each, and they arranged for a Saturday delivery for me.

I don't know what the shipping charge was but they were shipped from California.... and luckily, that's where I needed 'em.

[Jon Wehrenberg]

The relays on both my coaches are Prevost and Liberty.

They are a high amperage relay so Prevost has used them in many areas of the coach, and on both my coaches Liberty has also used them for several applications. I do not know if other converters use them, but they have been used in great numbers on my 1987, and in lesser numbers on my 97.