Fuse Block Relay Problem

[jeffwalt]

Do I have a relay problem? I'm experiencing intermittent operation with the dash fan blower, windshield fans, and the mirror adjusters. The leveling jacks are apparently on the same relay but have been working fine. Freightliner said get a relay at NAPA or check the plug in harness. I'm not sure what to check first and I do not want to mess up the leveling jacks. Any guidance is appreciated. 2016 Tuscany 42GX. The photo shows the accessory relay about in the middle of the fuse board and the accessory plug in harness toward the upper right. Thanks, Jeff

[Skip426]

The circuit board shown ; is not a Freightliner install; so I can't imagine why they didn't refer you to Thor in the first place .

The erratic functioning devices are all ignition on to activate an auxiliary ignition relay . The relay is in place to avoid overloading the ignition switch .

If your levelers don't require ignition " on " to operate they don't take power from that relay .

Do not pull on the relay too hard if you're trying to replace it , as some boards have the relay soldered in place .

What brand and series of levelers is your coach equipped with ?

[Skip426]

After blowing the photo up larger , it appears that fuses F-1>14 are for items that don't require ignition ON , right side of the board are fused circuits that require ignition on to function ,
What fuses #s are not operating and what # is for your levelers ?

Because if the relay is bad , no circuit fused on the right side of the board should operate , and possibly the red led above it should be lit.

Can you post a fuse diagram for that board ?

[jeffwalt]

I did call Thor and they were not helpful at all. They immediately referred me to Freightliner. My leveling jacks are Lippert Ultra Level and I don't think I've ever activated them with the ignition off. I will have to verify that. I'll also check the couple other things on the accessory list. I've attached the fuse board diagram. Thanks for the info and the help, I really appreciate it.

[Skip426]

Thanks for the fuse application diagram , I'll put it and the panel picture side by side and look over your list of , non functioning items ; then re-post if I have questions or comments .

First thing I did notice is the jack fuse ; being only 5 amp that must only be power to the control board , the control board must then activate another bank of relays to control the operation of the leveling system .

[Skip426]

OK, the non functioning systems and one you didn't mention , are the top 4 fuses on the board AND share the right side of the multiple connector . Yellow boxes.
If the rest of the fuses on the plug marked " Accessory" are still active when the three ( possible four ) Blower, Fans and mirrors ; don't work then the relay is not at fault .
The multiple connector has squeeze lock tabs , release the connector from the board and examine the pins projecting from the board for corrosion and touch them carefully to see if they are tight on the circuit board .
The wires in the connector should be in solid ; held in place with lock tabs on the connectors , first examine them to make sure they are all installed to the same depth , as viewed from the board side.
Then push the wires into the connector from the back , to see if they'll move in any deeper , then a light pull to see if they are locked in place .

[jeffwalt]

I can't thank you enough for your help! I think it's the relay. I pulled the plug and all the wires looked good and secure, no corrosion. The block on the board, also good. There are seven wires in the plug, all associated with the items not working (the photo of the back of the plug pins is upside down, I pulled it and twisted it down for the photo). All these spots come off the relay. The relay is not lit when the ignition is on, but the other one is. I tried to get the relay out but it's in there pretty good. I will try again later. The jacks controller seems to be separate, whew! Do you think I should try an auto parts store to find the relay replacement?

[Skip426]

The other possibility is the ; wire in the connector marked " K-1 coil +" that is the activation power for the relay .

Do you have full 12 volt power there ?

If not you'll need to figure out where Thor tied into the Freightliner wiring for activation power to their relay .

The relay appears to be a standard Bosch item , but like I said , caution when trying to remove .
Google the number on the relay , 80 amp is a HD unit standard is 30/40 amp.

Unfortunately if you have power at the , K-1 coil+ , wire the only way to check the activation power circuit across the printed board is with the relay removed , or dis mounting the board to access the back side to check continuity.

[Argosy]

If that relay isn't soldered to the board it has the thinnest socket I've ever seen. Pull the board off and check before pulling or prying on it too hard.

[Skip426]

Originally Posted by Argosy

If that relay isn't soldered to the board it has the thinnest socket I've ever seen. Pull the board off and check before pulling or prying on it too hard.

Good catch , Argosy , I was so busy looking at circuitry , I didn't notice that the relay was flush to the board .

jeffwalt , if the K-1 coil + wire has power the safest next step is to disconnect the batteries and remove the circuit board ; you have to see the back side to avoid damage.

It would also be the time to look for part numbers and a manufacturer's name .

[jeffwalt]

Thanks for the input. I have some homework to do. Good thing I didn't take the pry tools to that relay if it's soldered in.

[jeffwalt]

Originally Posted by Skip426

Good catch , Argosy , I was so busy looking at circuitry , I didn't notice that the relay was flush to the board .



jeffwalt , if the K-1 coil + wire has power the safest next step is to disconnect the batteries and remove the circuit board ; you have to see the back side to avoid damage.



It would also be the time to look for part numbers and a manufacturer's name .

Can I use the battery disconnect switch or should I physically disconnect the battery terminals?

[Skip426]

Originally Posted by jeffwalt

Can I use the battery disconnect switch or should I physically disconnect the battery terminals?

Best to totally disconnect the chassis battery use the coach battery disconnect and check that the supply cable is dead before you start .

EDIT : Did you check power at the K=1 coil + yet ?

[jeffwalt]

Originally Posted by Skip426

Best to totally disconnect the chassis battery use the coach battery disconnect and check that the supply cable is dead before you start .

EDIT : Did you check power at the K=1 coil + yet ?

Not yet. Long drive today. I'll check it as soon as I can and keep you posted.