Shuttle Coach Electric Problem

[Luminous Moose]

Hi,
I have an issue with the electrical circuit that powers everything connected to the accessories switch so I don't have interior lights, bus a/c or heat, power mirrors, etc.

Everything worked when we bought the bus a few weeks ago but it looks like a 40amp relay failed and the previous owner hot-wired a work around poorly and with a 16amp relay, it fell apart and everything stopped working. I got a new bigger relay and a new 40amp relay and rewired the connectors the way it looks like it should be wired. I got a power probe and there's battery power on the left side of the large relay, when I power the right side of the relay, everything works. When I power the small left wire, the relay clicks and everything works so everything should be good there.

For the 40amp relay, pin 85 goes to ground, pin 30 goes to the right side of the large relay and when I power it, everything works. There's pins 86 and 87 and two wires left and no matter how I run it, it doesn't work. One wire feeds back to the switch on the large relay. One runs to or from the accessories switch, when I give it power you can hear the ding ding noise like you're starting it up and the door is open.

Any idea how should this be wired?
Might there be something else wrong that would keep it from working when the key is turned?

Pic 1 is how it was wired, they just hot-wired a small wire across to the hot side that melted. Pic 2 is rewired currently, and pic 3 and 4 are close ups of the 40amp relay.

Thanks!

 

[BlackJohn]

Maybe this will help you think through the connections.


Didn`t you already post about this earlier, I seem to remember the melt down but what caused that before you try to fix this.


John

 

[BlackJohn]

I would add this to the above

Better explanation of 86-87 terminals


John

 

[Luminous Moose]

Thanks, John!

I had posted originally to my bus build thread but that was when I thought it was part of the original Ford wiring harness. I didn't realize my coach electrical problem had to do with the wiring mess So I reposted in the electrical section.

I got a new 5 pin 40amp relay, reconnected it so that 30 was power from the solenoid, 85 to ground, 87 to the solenoid switch, disconnected the two wires that were wired together and connected them to 86 and 87A and...lights! I've got coach lights, power mirrors, and everything back but now I stumbled onto another issue.

The fan for the rear a/c unit is now working correctly but there's no cold air and the a/c compressor on the side of the bus doesn't look like it's running. A/c was working when we bought the bus a few weeks ago. Also the rear a/c unit's heat is not working either, the dash light now lights up when I switch it to heat but instead of heat, there's a metal box with two fans in it by the wheelchair lift that runs instead!