RV has power, but won't turn over

ignition
chevrolet

#1

My friend is on day two of a road trip with a 1985 Itasca Sunflyer RV. The original Chevy 454 engine was replaced with a 350. It was all checked out and tuned up by a mechanic friend before they left and has been running great. Yesterday after stopping at a gas station, it wouldn’t start on the first try (just one click, no turn over), but on the second try it started up and ran fine. Today the same scenario, but after an hour of trying, it still won’t turn over, just one click each time the key is turned. There’s still power in the RV, so it’s not the power, right? Seems like it’s probably something really simple, but they called a local mechanic who said he’d charge $400 just to come out and look at it, and that’s not including repairs! Any ideas what it could be, or what they could try? My friend’s in a wheelchair, so it’s a very frustrating situation.

Thanks!


#2

Could be a bad starter. Try hitting the starter with a block of wood, or a hammer or tire iron. Sometimes that will jar the starter enough to make it work.


#3

Without a lot of details on the RV it would be hard to say that there’s any connection between what has power and what doesn’t and whether or not the engine gets turned over. A battery can easily be too weak to crank a starter but ok to run other things (at least for a while).

But before thinking about that, tell him to get a block of wood or something and give the starter a sharp whack and try again. If smacking the starter awakens things then the starter probably needs to be replaced (or overhauled). If that doesn’t help, step one is just to put a voltmeter on the engine’s main starting battery (I’m just assuming the RV might have another battery or two). It should read someplace in the neighborhood of 12.7V. If its below about 12.4V then the battery needs to be charged and tested before looking much farther. Many auto parts stores test batteries for free (and install for free if you end up buying one).

Next is to make sure that the battery cables are clean and tight and corrosion free - at both ends. The cables can be checked for resistance through a voltage drop test, and if all of that is straight, then you end up at the starter itself.

All of this is assuming that the one click is power making to the starter, btw.


#4

Just because the dome light comes on doesn’t mean you have enough juice in the battery to start the vehicle.

Does his RV have a boost button? Press it while starting. If it works, your vehicle battery isn’t putting out enough power. The boost button ties the house battery into the starting circuit to up the available power.


#5

Rv’s have a chassis battery and a series of house batteries. Thr chassis works the engine and dash thats it. The house batteries operate everything in the coach. Have him take off clean and put back together the connections on the chassis battery. And check connection at starter and grounds.


#6

Have they tried giving it a jump? If that works I’m guessing battery, connection, or alternator.


#7

Thanks everyone for all your suggestions! Some good people stopped to help out and they discovered a bad ground, so it was power after all. I think they’ve got it started again.


#8

Good. Folks forget that a 1985 is closing in on 30 years old, which in years gone by would be called an ‘antique’. Lots of things to keep up with…


#9

There was also a frayed wire going to the starter and the solanoid came disconnected in the process, but now it’s all hooked back up and on the road!


#10

Other than a visual inspection of the wiring and connectors, this type of problem is usually best addressed by a mechanic measuring the voltages at both starter terminals during attempted cranking. Measure between the terminal and the starter case. On econobox sedans both should be 10.5 volts or above. If so, and the starter doesn’t crank, the problem is the starter motor usually. If below 10.5 volts, certainly if below 9.5 volts – again I’m talking about econoboxes, not necessary RV’s – there’s either a battery, ground, or wiring problem prior to the starter. Best of luck.


#11

Has the engine overheated? I had a boat that I bought, ran fine then 2 years later troubles, the engine must have overheated in the past and all the electrical wires insulation was as brittle as those ribbon candies, with insulation breaks all over the place. After a few hours of splicing wires life was good, just a thought.