Going from memory of an 89 once owned. The only thing that was in the bay below the passenger seat was the squirrel cage fan and the manual air spool valve to run out the generator.
In the rounded corner of the body was a circulating assist pump for the dash heat. It can be seen from laying on the ground and looking up. It was only on when ignition was high and the temp control was towards heat.
Yours may be different from the 89 but that is about it as far as mechanical/electrical equipment in the area you are describing.
There is a pattern, about 8 seconds sounds like a valve or relay(just guessing) opening then closing after a couple seconds the another 8 seconds and it open and closes after a couple seconds etc.
Brad
there are a couple of remote possiblities.
1. the vacuum supply for the dash controls on that vintage should be an air powered pump. on my 90 it went out and i replaced it with a 12v pump out of a ford diesel truck. that should only be cycling on if the ignition key is on and there is a vacuum leak.
2. there is a merge relay in front of the passenger in the kick panel. or there was on my 90. that is besides the one in the rear. anyway, it might be a relay in that kickpanel cutting in and out from intermittant power or a bad coil.
3. there might be a self resetting dc fuse/breaker in there tripping and resetting.
just some say out there ideas
tom
Thanks Tom.
Since my last post I noticed the voltage on the coach batteries were at 12 according to the dash meter. Just this am it was much higher as I have the batteries merged to be charged from the solar panels. I also noticed at the same time my merge relay switch made no difference so either the switch went bad or the solenoid went bad. Odd that this is happening now. perhaps somehow connected. The ignition is off although the sound does remind me of a vacuum thingy I played with in my earlier years on older vehicles. But I would like to think that especially if it needs 12 volt by ignition that, that is not the problem.
Will ponder on this this evening then go at it again sometime tomorrow. We are in the process of winding down here at Senator Wash and preparing to head north on our Alaska trip sometime early April. The coach will go into storage in Yuma.
Brad
brad, will you stop by wittmann and visit us on your way north?
tom
on us 60 between wickenburg and surprise. i will email you my address.
we would love to have you.
tom
I have the location of the noise closer to the mid section maybe just behind the gen box perhaps under the coach. What could be in that area?
Brad
Heater fan relay? I'm stretching here
To hot to run the heat. I plan on climbing under the front to see what I can see but it will have to wait a couple days as we are supposed to have high winds tomorrow with gust up to 50 mph.