The 700 series locos did not have an auxillary power source, they were strictly for propulsion. The APCU's and APU's provided the hotel power and usually were on the train with them. The only time they weren't was in the incident in Burlington when 526 was on the other end of the train with 706. I spent a couple of days on site using 526 to switch the rerailed cars into a siding to have the west end couplers replaced. The couplers had to be burned off because they wouldn't unlock with the stress on them. The cars could only be picked up one at a time so they had to be seperated.
Note, they had no auxillary power. The special features were 575v trainline so wayside could be run through them. They also had the layover feature which operates off 575v. All GO locomotives have had this feature since the late 70's early 80's. The F59PH's were bought with it. This involves two pumps, one for lube oil and one for coolant and a 575v immersion heater. The cooling water is heated and the circulating pump forces the heated coolant through the cooling system in the engine and air compressor. When it goes through the lube oil cooler it heats the oil which is being circulated by the lube oil pump.
The lube oil cooler has been modified so there is oil in it at all times by moving the discharge from the bottom of it to the top. Before the modification the cooler would drain when the engine was shut down thus there would be no oil to heat. This system works much better than it did on 500 to 507 and 700 to 711 as they had hot water cab heat with supply lines running under the running board/walkway. It was difficult to maintain enough flow to prevent freezing and it often did freeze. Many crews had a very cold trip out of the outposts on winter mornings.
The F40PH's, GP40-2m's and the F59PH's all had or have electric cab heat with extra heaters operating off the wayside supply. There is also a battery trickle charger to keep the batteries at peak capacity for cold morning starts. The nominal battery voltage is 80 but when those two big Delco starters start turning it drops to about 50. A drop test is performed on the batteries with a volt meter and if it falls below 40 volts they are replaced. Battery life is about six years. Some of the older F59PH's are on their third set of batteries.
Further, when a GMD is shut down there is no water in the radiators. Once the water pumps stop the water flows back into the expansion tank inside the carbody were it is warmer and takes much longer to freeze. That is the reason for the two full marks on the coolant sight glass, one for running and one for shutdown.
The APCU's had a similar system to the one on the main engines. The Cat engines in the F59PH's uses a heater mounted low in the cooling system and use convection for circulation.
Our locomotives have a voice alarm system connected to the UHF GO radio to warn of doors being opened on the coaches at outposts, wayside power failure, low coolant tempature and coolant is dumping. There is a tempature sensitive drain valve on the cooling system that opens just below 60 degrees F. to drain the system to prevent frost damage. The main engine doesn't use antifreeze but only corrosion inhibited water.
The water system on the coaches also have a similar valve but doesn't send a warning.
* Notes courtesy A Johston, GO Transit