Dash AC & Burnt Plug Wires

[max49]

I burnt one plug wire during the whole 3 yr warranty period and now I have burnt one each on the last 2 trips. I bought a whole extra set so I still have 6 left but It's still a PITA finding the bad one.

I also got reminded that my dash air is absolutely useless in a traffic jam or at speeds below 35 or maybe 55 MPH. It just starts blowing hot air, even with the AC fans on. Then it turns cold again once I start cruising again.

I have a plan that may work, or at least help. I went out and bought a 4" marine blower made for ventilating the engine compartment on boats. It's 4" so clothes dryer hose attaches right to it. I've mounted it in the front and ran the hose above the master cylinder and blowing right between # 3 & 5 plugs. (the ones that have given me all the trouble)

The blower puts out a lot of high speed air @ 230 cu ft per min, so I think it should cure the SP problem, unless other side on the engine starts burning them.

Has any one tried this? I'll have fans every where, but I'm also thinking about putting one in front of the AC condenser or whatever it is called. Can't hurt but I wonder if it would help. As soon as enough air blows thru it the AC gets cold again. It's already got the 2 factory fans, but that is obviously not enough. Any body else have this problem with the AC? Mines been like that since it was new.

I'd appreciate any thoughts on this. I'll post some pics when I get a chance, just to show the idea and functionality.

[TrekPR]

Do you have the AC on Max when traveling slow? The hot air builds up where the AC intake is and it won't cool it down enough to feel anything but hot in the cab.

[DriVer]

Max, JestMe13 had bilge pump blowers installed from Workhorse on the cold air vent kit to attempt to resolve an overheated wire condition on his 05 P32 Monaco Trek he was having. Even with the cold air kit (hoses), Taylor wires and everything he could think of he still would get failed #5 & #7 wires I believe. The failure would happen on a severe climb.

The bilge pumps were installed to see if it would help anything but he didn't keep the rig long enough to find out if the pumps were going to work. I believe he did report that they were quite audible so that added to the overall noise signature of the stuff under the hood.

Since then Steve has moved on to his current RDP. I expect that aside from his generator things are pretty quiet under foot.

[Sammie]

Max, I have owned several gas rigs in the past 30 years and on each one I installed a water mist sprayer on the front of the radiator. I used the water spray only while climbing long hot grades and never burnt a spark plug wire. I would start driving uphill and watch my water temp gauge begin to raise and after switching on the spray the engine temperature would immediately drop down. There used to be a company that sold a Desert Supercooler system that you could buy and install yourself but I have always made my own, not real hard to do. Below is a link to the Desert Supercooler system.

http://www.rvjournal.com/SuperCooler.html

Sammie

[max49]

I never use any thing except "Max" on the MH or any other vehicle. I don't know why.

My temp. gauge stays welded in the middle and never moves once it is warmed up. Climb mountains or sit in a traffic jam, it doesn't move from the middle. I don't know why.

The water spray might help the AC, but it just seems like such a 'heroic effort' and I doubt if it would help the SP wire problem.

98% of the time my MH goes any where, it has to climb mountains. I'm sure that could be a contributing factor , but even at 30-35 MPH, there should be air moving around the plugs. Traffic jams, that hot air just sits stagnant so I'm not sure which is worse.

I know I'm getting tired of it and trying to find the bad wire. Some times when I pull the wire off , the little metal thing comes out of the wire and stays on the plug. Can that just be pushed back in, or is that wire ruined when that happens?

Thanks for the encouragement Driver , but I can't afford a DP right now

I put the blower in and routed the hose, it does'nt look very good, right in the wheel well but I guess I'll see if it seems to help.

Can you guys sit in a traffic jam in 90* weather and your AC still blows cold? I think it's the lack of enough air blowing through the condensor but I guess it could be the low RPM of the engine/ compressor that pretty much just shuts the cooling down. I tried to get it fixed while it was under warranty but they just said 'it was the nature of the beast' and was working normaly.

[DriVer]

Quote:

Originally Posted by max49 I know I'm getting tired of it and trying to find the bad wire. Some times when I pull the wire off , the little metal thing comes out of the wire and stays on the plug. Can that just be pushed back in, or is that wire ruined when that happens?

Max, Once the connection to the wire is broken, I can guarantee you that the wire is no longer reliable and will need to be replaced. I have a number of spare wires that I wish I could just let you have but it would cost a few bucks just to mail you the wires and it'll take time.... You'd be better off going to your local jobber and pick up some wires. If you do continue to get failed wire problems consider upgrading the quality of your wires.

About the A/C, if you are sitting still in 90 degree traffic it isn't going to get anywhere near cool, until you start moving air over the condenser.

[max49]

Thanks Driver, I still have 6 new (cheap) wires left from the set. The new ones have'nt failed yet. So # 3 & 5 are aftermarket. I'll see how they do. I would sure hate to burn those $163 Taylor Supremes, but am thinking about trying them, maybe.
I guess it would look pretty tacky , but I'm thinking about leaving my hood open on some of the steepest and longest climbs. Has that ever been tried?
Too bad someone didn't make a nice louvered cover for the hood. One size could fit many models. Maybe an option of being able to open or close them from the cab. It would'nt be that difficult to cut out the hole if I had something nice to fill it in with. Seems like it would help to have air blow straight into the radiator like trucks do, rather than underneath the radiator.

[Clay L]

The temp gauge is designed to stay in place unless the temp heads out of bounds. It's really sort of a glorified idiot light.

I have coolant temp as one the gauges showing on my ScanGauge and it runs at about 200 degrees a lot of the time with increases to 211 or so under certain conditions such as pulling grades. Then the engine fan kicks in and it drops back down. As it's designed to do the dash gauge never moves a bit.

I run the generator and house ACs most the time when I need AC. As recommended I do run the dash every so often though.

[oemtech]

Clay,

I did a bit research on the Workhorse temp gauge and yes it is some what a glorified idiot light. The middle point of the gauge is 188 to 224 degrees. More info at Oemys Tech Tips.

[Max Hubrich]

Max49,

An easy way to find the dead cylinder is to get your WD-40 out-- with the red spray nozzle in place, and squirt in on each exhaust manifold port. The one that doesn't smoke has the bad wire/spark plug.

I've done this frequently on my 'ole 454 HR motor home. My problem was caused by the crummy (and cheap) headers I put on it. later I changed to Banks and my problem ceased.

[max49]

Thanks for the tip Max Hubrick, good idea. Is the theory behind this that the dead cylinder/ exhaust port will be much cooler? If so, maybe my laser thermometer will come in handy here also.

Since my radio in the MH is pretty much unused, because of poor reception, does any one know if they still make the old copper SP wires for the 8.1 ? If so, maybe they would hold up.

[DriVer]

Quote:

Originally Posted by max49 Since my radio in the MH is pretty much unused, because of poor reception, does any one know if they still make the old copper SP wires for the 8.1 ? If so, maybe they would hold up.

Max, Copper wires just won't help. The 8.1L engine was never designed to run on copper so there aren't any copper wires for it.

I ran OEM wires without any trouble until I upgraded to Taylors. If you are having problems, you have to investigate the problem and not the solution. The solution will come once you've ID'd the problem. That's the easy part. How's your air dam holding up and is it in place?

Opening your hood while climbing, again not a practical solution ...

[max49]

" The solution will come once you've ID'd the problem. That's the easy part. How's your air dam holding up and is it in place?"

That's not the easy part. Gee Whiz, I can look right in the wheel well and see # 5 plug & wire , so it looks like it should get plenty of fresh air. They use the 8.1 in boats in a totaly confined space and I haven't heard of this problem with those.

My air dam is all intact and in good shape but I do have it folded up to make checking engine & tranny fluid easier on the passenger side. The wires that have been failing, thus far have been on the driver side. I could easily flip it back down but I have my doubts it will help.

Why do we say they are "burnt" ? They don't look burnt.

"Opening your hood while climbing, again not a practical solution ... "

Maybe not, but that would allow the air to slam straight into the cool pack and engine compartment, more similar to other vehicles.

[Doug Sage]

I had a problem with heat and burned wires on both banks. Workhorse has a duct kit that is designed to bring in cool air to the spark plug area. They installed two of these kits and replaced my plugs and I have been fine ever since. I have traveled the Rockies twice now with no mis-firing problems. You might want to check this out.