Progressive EMS - Bolts Missing, Loose Parts, YEARLY Maintenance Item

**Galway Girl** · 2025-07-24T01:07:16Z

In a recent facebook post the Progressive EMS that is located under the rear dinette seat came into question. The poster had been concerned about the other posts about the transfer switch and decided to look at the wiring in the EMS Unit in the same dinette seat bay.

Below is one of the pictures he posted showing his burnt wiring (in the white circle).
He also posted a videos showing the main power switching board completely loose as the bolts holding it in place had fallen off.

Since I already check the connections on the transfer switch each year, I decided I would also check my Progressive EMS unit as well.
Good thing I did as the bolts had fallen out just as in the Facebook Posting.

EMS and Transfer Switch Locations: Under Rear Dinette Seat (next to Pantry).

Looking down into the under dinette seat you'll see the Progressive EMS is held onto a vertical mounting board near the aisle. It's held in place by 4 - #2 phillips screws into the board.
The Progressive transfer switch is across from the EMS on the forward wheel hump (for units with front and side street power inlet option.)

Safety FIRST- Make sure you're not connected to street power and that your Inverter is OFF. To be really safe you may want to shut off batteries as well.

1) I placed a towel under the EMS unit work area because I've lost more than one screw down the abyss.
2) Removed the 4 #2 phillips mounting screws from the corners up the unit.
(Note - to access the top front screw you likely will need to detach the cable that connects to the remote display...it's a network clip connection.)
3) Tilted unit so it was facing up.
4) Removed the 6 - #1 phillips screws holding on the lid.
5) Inspected the wires and none were scorched.
6) Wiggled the main connection board and it was very loose...one of the two nuts holding it onto the 2 mounting bolts was loose, lying in the bottom of the case.
7) Checked for bolts (thread through back of case) Luckily the bolt was still attached to the case.
(They are phillips head countersunk bolts. Which after working on them I taped them in place from the outside.)
8 Reconnected the bolts to the nut putting on blue thread locker.
9) Checked tightness of all the lead screws and the bolts on the 3 ground lugs (green). See PIX below:

10) Put lid on and then re-attached to mounting board and re-attached remote display network wire.

Tested with shore power and all was well

Tricky Bits: Getting my hands into the bolt area was a trick.
I got a proper size nut driver and put a bit of tape inside to hold the nut flat in place.
I carefully threaded the nut driver down to the bolt which had blue thread locker already drizzled in place.

Progressive Transfer Switch inner connections above:

I've submitted a ticket to Oliver, and a letter to Progressive Industries and requested a service note about yearly maintenance.

Here are the wiring diagrams from the PD Manual for this item: