I have a train horn on my truck with a VIAIR 380C compressor and a 5 gallon air tank. I have a standard 2 terminal 165-200 PSI pressure switch. Occasionally my compressor will not cut out at 200 PSI and my safety valve will blow off at 235 PSI. I have a guage in the cab of my truck and the gauge reads 235 PSI when I hear the safety valve blow so I dont think the problem is a faulty safety valve. I know the standard 2 terminal pressure switches are not the best so I am looking to upgrade my pressure switch and see if that fixes my problem. What doesnt everybody recommend for a good pressure switch?
Also my second problem is I am running a 30 amp fuse on my compressor and the compressor has blown the fuse 3 times now. I will admit I dont know a lot about 12 volt wiring so I am looking too you guys for help. I do know that a loose connection can cause the compressor to draw more amps and blow the fuse so yesterday I checked all my electrical connections and everything seems to be okay. I did notice that some of my connections are getting wet but I am not sure if that would cause a fuse too blow? The only other problem I can see is that I have my 40 amp relay for the compressor mounted on the framerail beside the compressor where it is also getting wet. I know this is also not good for the relay so I am thinking about upgrading to a waterproof relay. Thanks and any help is appreciated.
Check to see if the check valve is working properly in the leader hose for the compressor. If it stays open, the compressor could blow a fuse on restart.
Relays & pressure switches are straight forward. They either work, or they don’t.
Thanks for the help Lance. I had time this weekend to pull my leader hose off. As soon as I got it off of the truck I blew with my mouth through the leader hose and check valve and I could blow both ways which tells me the check valve was stuck open. I then took my shop air compressor and blew through the leader hose and check valve against the check valve and and good blast of air got through then I could hear the check valve close and no more air was getting through. But if I blow back the correct way through the check vale it opens and when I blow back against the check valve it still lets a blast of air through before it closes.
Should the check valve close instantly and not let a blast of air through? It seems to me like the check valve is sticking open after the compressor stops pumping. Another thing I noticed the other day is that my compressor is loosing air alot faster now then it ever did. I am thinking the check valve is sticking open and my air is leaking back through the compressor. And when the compressor starts up it is blowing the fuse.
I’d replace the leader hose. Be careful when installing, not to over-tighten the hose. The NPT fitting can capture the washer and lock the check valve in place. The newer leader hoses have updated check valves that this should not be as much of a problem with. Just try not to tighten it orangutan-tight, ya’ dig?
Lance. I purchased a new leader hose with check valve this weekend and installed in on my truck. The compressor ran a few times over the weekend and it didnt blow the fuse. Until monday when I was on my way home from work. I was sitting at work with my truck on high idle letting it warm up. My compressor was running at the same time. I reached down to turn off my high idle switch which is right beside the switch for my compressor. I accidentally turned off the compressor switch and when I turned it back on the compressor didnt come back on(My tank was only at 150 PSI so it should have came back on when I turned the switch back on) So i got out of the truck and checked my fuse for the compressor and sure enough it was blown.
Do you guys have any other ideas why my fuses keep blowing?
Without blowing the unit apart and inspecting it, this usually is the result of the check valve, or intake/exhaust valves. If one of them is not closing properly all kinds of neat pressure problems develop, most of which cause high amp draw and low voltage. Its the amp draw that blows your fuse.
Lance is it difficult to take one of these things apart and inspect it? I am a heavy duty mechanic and I doubt taking apart and putting this compressor back together would be any harder than a inframe of a diesel engine. Are there any gaskets/seals that are not reusable when I take this thing apart? And are there any parts inside the compressor that I should replace as a preventative maintenance type of thing since I will have it apart anyway?
On the weekend I am going to re check all of my wiring and make sure I am getting a good ground. I am also going to ditch the cheap pressure switch and relay for one of those nice viair pressure switches with the built in relay. If all my wiring checks out I am going to proceed with opening the compressor up and inspecting it.
Most of the seals should be re-usable. You won’t know for sure what you need until you get into it. The first time is the most difficult when taking one apart for inspection and repair. It gets progressively easier from there. If you’re mechanically inclined, I don’t see this as difficult for you at all. You should only need to replace what looks wrong. If you change the piston assembly out, change out the cylinder as well to keep the sealing surfaces fresh.
Well today I looked over all of my wiring and cleaned up my ground point. Then started up the compressor and it made it up too 60 PSI before she stopped. I figured damn she blew another fuse. Opened the hood to find the fuse not blown. Next I start thinking my pressure switch crapped out so I jumped out the pressure switch and the compressor still didnt run. Then I checked for power down at the compressor and sure enough there was power there. So I figured the compressor has finally died and proceeded to remove it from the truck so I can take it apart.
Well I got the compressor apart and I get the idiot of the year award. The damn compressor had water inside and looks very ugly. I doubt it can be repaired so I am now going to try and save up some money to replace the compressor and maybe upgrade to a 480C at the same time.
I also checked my filter and it was wet. When I installed the compressor I was going to run the filter up into the engine comparment but found a nice place tucked up on the frame rail that I figured would never get wet. Well I guess I was wrong.
