1988 345... The adventure begins!

[Paul J Mauro]

Originally Posted by Roby466

Running the brand new furnace gives out some burning smell at first. The heat exchanger is painted so I suppose the paint is burning off.

Furnace is much quieter than the original and starts right away, every time!!

after 38 years its time to replace both heaters who are hard to light ,leak and smell .looking at Atwood to replace the Duo Therms .

anyone used these replacements ?

[Roby466]

I looked at them but I didn’t want to have to cut a big hole in the outside skin. The front one was fairly simple to fit in the existing holes. I am not replacing my bedroom heater now but that one has horizontal vents so I would have to do more measurements to see what furnace to use. I’m thinking the same one could still fit if using a flexible intake hose again.

[AirStreamMar]

Originally Posted by PeterH-350LE

I have done both, short wire from the battery to a 30 amp breaker and onward to the compressor and on a 87 345, I added a 30 amp breaker to the existing by the isolator.

The relay can be right at the compressor, with the existing yellow wire serving as the ignition activated signal wire. On my old 1983 310, I even created a whole new small power panel close to the compressor, to add whatever else I wanted in the rear at a later time.
But as with so many things the location of the compressor has changed just about every year.

Also my GM fuse box has melted in the past and I smelled it again when I started the engine recently. So it's time to do the relay thing.
What is the best position for the relay - electrically? The yellow line comes from the GM fuse box circuit B-4 and goes into the High Pressure Switch (#8 on the Air Line Schematic). Shall I just cut the yellow line to trigger the relay and using house power to be switched by the relay and then connect to the High Pressure Switch. Or is there a better suggestion?

[bkahler]

I put the relay in the same compartment as the compressor and compressor shutoff switch. I used the yellow wire to drive the relay. The relay contacts are powered from the house battery. I chose the house battery because I wanted to remove as much load from the starting battery as I could.

Brad

[Cameron1976]

I read that you replaced the front shocks did you replace the shocks on the tag axle? If so what did you use?

[cmadmaxman]

Here is what I installed on our 350.
Same as the trailers.

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[Roby466]

Originally Posted by AirStreamMar

Also my GM fuse box has melted in the past and I smelled it again when I started the engine recently. So it's time to do the relay thing.
What is the best position for the relay - electrically? The yellow line comes from the GM fuse box circuit B-4 and goes into the High Pressure Switch (#8 on the Air Line Schematic). Shall I just cut the yellow line to trigger the relay and using house power to be switched by the relay and then connect to the High Pressure Switch. Or is there a better suggestion?

I have installed a fuse in the house breaker panel (under stove) and ran an 8 gauge wire behind the shower to the bedroom area. The relay will be mounted right there beside the pressure switch.

[Roby466]

Originally Posted by cmadmaxman

Here is what I installed on our 350.
Same as the trailers. Attachment 427077

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Thanks for this!
I did the front shocks with some Bilstein and next summer I'm doing the 4 rear shocks and air bags.

[Paul J Mauro]

Originally Posted by bobmiller1

Note.....if the air intake / exhaust is horizontal, they’re junk, don’t waste your time. They are known to be silent killers (Carbon Monoxide) . Regards, Bob

Time to replace both furnace units that are the original dometics and they are quirky dont always light etc .been researching and looks like ATwood has the right size unit .Do you think those are good choice? the "silent killer" comment got my attention after I smelled some propane recently.
Thinking of going through the whole system since its way overdue.

learned a hard lesson this summer on the way from New Mexico back to Mass when the panic stop I made to avoid an idiot ruptured an original rusted brake line about 4 inches from the master .
quite a ride getting home on just rear brakes !I guess as we age our pipes get rusty but we still get out there .hope all is well with you.maybe cooperstown

[Roby466]

Paul, what are the furnaces in yours? Which model Atwood are you looking to install in there? There are a few options as pointed out by others here but I have decided to go to the Suburban due to not wanting to cut my skin outside.
Also, replace the CO detector with one that does both propane leak and CO as well.
Of note if my bedroom one needs replacing I’m contemplating installing a Webasto air top gasoline heater instead. I think the bedroom heater is oversized and I could tap in the generator line for fuel source. The air top is a much smaller unit so it would fit nicely there. Others who have replaced the bedroom furnace have had to modify the black tank vent to allow for the newer deeper units.
Cheers
David

[Paul J Mauro]

Hi david
we have duo therm 900 series originally
looks like atwood 12000 btu
part # 38916 would fit kitchen and bedroom without cutting
body parts

[Roby466]

Looks like that would work. Odd that it only has a single vent to the outside for exhaust. I suppose it draws combustion air from within the camper instead of from outside.

[Roby466]

Just got back from our first trip of the season…. I think this doesn’t sound good…

https://youtube.com/shorts/u2awn-HMGuU?feature=share

[ITSNO60]

Ouch, I hope I'm wrong but to me it sounds just like a rod. Could have spun a bearing. What's the odometer at? Praying it's top end but doesn't sound that way on the video.

[ITSNO60]

Found this: https://www.google.com/search?q=soun...id:Pu2RHsIGBXU

It's a 454 with a spun bearing/rod knock.

[cmadmaxman]

Here is our 310 that run strong, but when idling this is what I had.
Did not tear it down to see what it was, just replaced with GM rebuild.
We run it for many years, but was getting to a point that I could not trust it anymore!

https://photos.app.goo.gl/dSRb6qMTE7Xg76jQ9

[Roby466]

Yeah…. Not encouraging.
I have 81,500 miles on the clock. It was running quite well and I noticed the added noise when I got out of the highway, I had just done a 300 miles highway stretch with some hills but nothing out of the ordinary, temps were fine, oil pressure was strong, and all seemed to run smoothly.
Chevy rebuilt you say, did you get that from an engine builder locally or Chevy actual?
Thanks

[cmadmaxman]

I had bought it off ebay, but it was Jeg's store.
Fast shipping, had it in less than a week. You have to have a place that has a fork truck to remove from the truck, or pay high bucks for home delivery!

[ITSNO60]

Although it sounds like a rod don't give up on it without checking some easy things. Check for a cracked flex plate although that will usually get quiet when in gear. Check the top end (bent push rod/rocker/collapsed lifter), check for exhaust leak where manifolds bolt up to heads, remove drive belt(s) to rule out engine driven accessories. A length of tubing or PEX can be handy for locating the area where it is coming from, just be careful around the fan and belts. Opening the oil cap or breather and listening down inside the valve covers can help find a loose valve train part.
It honestly sounds like a rod but it would be a shame to condemn it without checking the simple stuff first.

[Roby466]

Originally Posted by ITSNO60

Although it sounds like a rod don't give up on it without checking some easy things. Check for a cracked flex plate although that will usually get quiet when in gear. Check the top end (bent push rod/rocker/collapsed lifter), check for exhaust leak where manifolds bolt up to heads, remove drive belt(s) to rule out engine driven accessories. A length of tubing or PEX can be handy for locating the area where it is coming from, just be careful around the fan and belts. Opening the oil cap or breather and listening down inside the valve covers can help find a loose valve train part.
It honestly sounds like a rod but it would be a shame to condemn it without checking the simple stuff first.

Yep, going back under there with my ''mechanic's stethoscope'' this evening and will try and figure out for sure where it comes from. I would love for it to be a cracked manifold that somehow sounds like a bottom end knock!! That would make my day (or more likely my summer!).
I'll report back later this evening once I'm done crying or laughing depending!!