Whats up fellas, I've used this place as a source of information for everything Ive needed for a while, but now I have this question I cant seem to find an answer to, I have a ford 555d and Ive been on the NH site to follow part schematics also. My heater doesn't respond when I turn the fan selector in the on position. I look at my Fuse box and it appears that one relay is missing in th lower right corner of the box, but I cant seem to find any part number or schematic to confirm it. There are 5 relays, all identical, but 6 places in the box. Now the 6th spot also ha the pin config different than the other 5.... It has 4 spots, the middle, and one at 9, 12, and 3. 9 is a good ground the middle is hot with the key, 3 tests positive when the fan selector is turned in the on position 12, I have no idea... I am at a total loss and cant seem to find an answer, I had too much down time today and can not afford anymore, please help me out if you can. God Bless Doug K
Good grief Doug, is it that cold in the Poconos that you need the heater that badly ? Did the heater quit working ? Or has it never worked. Because if it worked and then quit ,that missing relay wouldn't be a factor unless someone stole it. Can you run a wire from the switch directly to the fan until you can get a schematic diagram or some help from someone that knows how it is supposed to be wired ?
Hello Doug..It won't be a relay, it will be a fuse usually dedicated to the fan usually 15amp. On my 655 its F2/B (15A BLUE). For others info mine has the fuse label under the lid but not what they do, thanks Ford/New Holland for being classy... There was a posting if you google about the 555 wiring diagram(s) and where/how they hook to the fan..
I purchased this in the spring, but I'm getting concerned about the heat as the temperature has been dropping. All the fuses check out ok., but one of the best parts of this machine is that it appears to never have been tinkered with and all oem equipment. I am just so confused as to how the fan controller would effect the readings in the relay location, if it wasn't related somehow. I'm still new to this tlb, but usually don't get stumped with these little problems. I'm going to look for that schematic
Well if you checked the fuses then the next step is to start tracing it through. One of those 12v cheap testers would work fine. Don't get hung up on the relays they control things like lights, transmission shuttle, return to dig, etc. so the number depends on original equipment options. Start with fan switch and just see if you power there, heaters are just a blower and he with the selector (fan speed) varying the resistance to control the speed. If you have power there then its further down the circuit (ie at the fan). Sometimes it can just be a bad ground on the fan.
Don't discount the possibility that the fan motor is defective. That is why i suggested in my first post to run a known to be good 12 volt supply to it.