170w GoPower solar only supplying 1.5 amps in direct sun.

Thanks! I will report back as soon as I get answers.

FIrst never expect full rated power from teh panel. that is delivered into an "Ideal" load and those do not exist outside the lab

Second. Several reasons listed above affect output. Direct sunlight on the equator art high noon on a cloudless dustless sky. Perhaps. You are north of the equator and the air is getting dustier all the time. Several causes. Including the Town of Paradise, CA. which is no more due to one of the causes.
And though you may find my wording funny.. IT IS NOT funny.. Not one bit.

That low of amps reading would be due to:
a) low-angle sun
b) shadows
c) faulty controller
d) faulty wiring
e) fully charged batteries.

So the low amps seen are from the panel to the controller. You don't know the amps to the battery.

The problem is not simply between controller and battery. Panel voltage should be nearly the same as battery voltage with PWM, which can affect panel amps (IV curve)

Yep, needs a multimeter to check voltage starting with the panel at its pigtails, then each connection. Your first suspect now is where the panel pigtails connect to the "input wires" on the roof. If the panel has a junction box on the back instead of pigtails, that is a problem how to get at it now it is mounted.

If the panel voltage as seen at the input to the controller is ok, then you don't have to check at the panel, which saves a lot of trouble. Still need to find those missing amps though.

BFL, Thats the controller. Once I have a meter, I will have better readings, I am using the display for now.

I am assuming the 1 to 1.5 amps is measured at the batteries by say a Trimetric monitor. If the amps are from the controller's display, then that is a whole different story to figure out.

The blurb on the kit says it has 25 ft of #10 input and 25 ft of # 10 output wire which should be ok for the 8.9 amps it says it will do.

The controller is this one. Interesting about that boost button.

https://gpelectric.com/wp-content/uploads/2015/06/GP-PWM-30-UL_Manual-with-French_2018-04-10.pdf

BFL, they are pretty thick 2/3 thick as a jumper cable. Listed as MC4 output cable, and maybe 4 or 5 feet. But, I cant see the termination directly into the batteries. I do see a multi terminal splitter to the side of the batteries, and I don't even see them terminating directly into that thing. I am wondering where they spliced them into the coach now. Hmm.. the hunt is afoot!

How long are the pos and neg wires from the controller to the battery bank and what is their gauge? Too long and thin means high R and low amps. Also means the controller thinks the battery voltage is higher than it really is and it will drop to float too soon.

It shows in the manual, running two 6v and a panel on this controller. I was curious if there was a setting though, it is set to flooded batts, but did not see any further options.

I hope the GoPower controller has adjustable voltage set points.