Recently purchased a 1986 motor home on a 350 chasis and a 460 motor. It is burning-up alternator belts. Interesting thing is that the overall engine performance improves significantly when the belt is off. I'm wondering if the smog system is causing the problem. New belts, proper tension and the alternator seems fine.

David

 

Welcome to FTE!

First, I would take off both belts and check the alternator and smog pump, to see if they turn freely.

After that, I would put the alternator belt back on but leave the smog pump belt off, and see if the engine's performance changes. If there's no change, then your smog pump might be on its way out.

 

I have an 87 motorhome with the same setup as yours. Mine was eating belts and we found that one of the two smog pumps on it was froze solid. Wasn't all that expencive to get or bad to change out. Once done it ran a heck of a lot better.

 

Thanks for the welcome and info!

I haven't pulled the belts yet but will be doing so tomorrow. I turned the belt with the alternator and two emission controls and it turned freely. Does engine RPM or overall output have an effect on the smog pumps if they are going bad? Seems like my belt problem was changed by overall output and performance was bad too.

I will report back tomorrow too.

 

Welcome to FTE dcphoto and Rusty Bucket.

 

What's the voltage on the battery with the alt belt on? Had a regulator fail once and caused the alternator to pump out lots of voltage and it did pull the engine down in RPM's. But most likely a air pump is locking up like the others said.

 

O.K. new belts today. I went ahead and did all of them and think I have the alternator belt on even better than before. I did a test drive with just the alternator belt hooked-up i.e. no air pumps and the belt worked fine. Engine performance is so much of a feel but I feels a little held back. The volt meter in the cab is pretty much pegged but the volt meter with the engine OFF is about 10V and with the engine running it's more like 13-14V which is about right? It's not a high end meter and I'm not sure the calibration is right but the variation seems about right. Why the needles is pegged I'm not quite sure. I have reattached the smog equipment but have to wait until tomorrow to road test it. I did hand spin both air pumps independently and both seem to spin freely. Not easy really but pretty free with no binding feeling.

 

Did you make sure the alternator is spinning freely as well?

Is the gauge factory or aftermarket? I ask because I've never heard of the 80-86 trucks or vans having a factory voltmeter, but rather an ammeter.

With the key in the Run position, your ignition system would be drawing power, and that would cause a reading of 10-11 volts. Do you get the same reading if you turn the key towards you to the Accessory position?

EDIT: Eddiec1564, I had something like that happen to me on a dark road one night....the voltage regulator had a fit and let 17 volts through. I think it was mainly a result of my headlight switch finally going out....it blew out my headlights, but nothing else was harmed. Went back to 14 volts after the headlight switch blew. I had an Optima RedTop at the time (still have it), and it wasn't even affected. lol

 

You got lucky, that happened on my 84 F250, fried the radio and also killed the TFI mod! I know it had to be over 20V as inside the radio are zener diodes rated at 21V for surge protection. they were shorted out causing fuse to pop. The engine just died and I had to walk home and get my Dad's van to pull the mule home! AND that was the only time a cheby pulled it home!!


Dcphoto ,sounds like the air pumps are failing, if you have no cats and no smog checks, I'll leave them belts off and take the extra weight off your truck. Those air pumps will "feel" good when cold but will usually lock up once warmed up.

 

O.K. disconnected the smog pumps all together but was still having some problems. Truck draws 2 amps even when it's off. Sounds like the alternator then? I hope! Disconnect alternator and truck draws zero amps. I pulled the alternator today and have a new one ready to go for tomorrow. New question is how to I get the pivot bolt in without taking out the radiator??? I don't see how and ended-up cutting the old bolt to get it out.

Thanks for all your help!

 

check that the pully's are lined up, that could cause it to eat belts. van's suck on to work on, but if you take off the fan shroud, you should be able to get the bolt out without removeing the radiator

 

The fact that it's drawing power when nothing on should have been my first sign I think. I pulled the pivot bolt out today to removed the alternator and it was up DIRECTLY against the radiator and still had about 3/4 inch to go before I could get the bolt out. It wobbled around a bit but wouldn't come off even when I got awnry with it. Finally I just cut it. I have a shorter bolt that I'm going to try tomorrow with the install of the new one but I'm doubtful.

 

You have a bad alternator, one of the diodes is failing and that will cause a dead battery and also will lug down the engine. I haven't had the luxury of changing a alternator on my 95 E350, it's been converted with a 150A alternator and a 2nd AC compressor(for bus use, now its a RV), they got it crammed in!

As with all vans, usually best to pull the radiator as they tend to get smacked up and youl'l have leaks later.

 

There will be some constant draw but very minimal when the key is off which is the power to the radio memory, clock, and the engine control module. I went nuts trying to sort out the gremlins in the electrical on my F-150 until I found out how much constant draw there should be when the truck is not running.

If that volt meter is an aftermarket, I'd be thinking that it is not set right for your vehicle or it's a bad unit. If the alternator tests out at 14 to 14.5 volts output, then it should be fine. I usually test them with a volt-ohm meter across the battery terminals when the motor is running.

 

I just purchased a '81 Holiday Rambler last Fall and upon pickup recently , all the vacuum hoses had been taken ... I haven't been able to find a schematic for the hose setup anywhere , although I am waiting on a CD we ordered but haven't received yet . Can any one head me in the right direction as we need to have it roadworthy by Friday ???
Any help would be appreciated . I'd love it if someone had a closeup picture of the engine in theirs ! ( We have to purchase all the hoses also ) Thanks for ANY HELP.
( Neither Ford Mfg couldn't help me and only one dealership had a basic illustration they emailed but it's pretty blurry ? )