Lift system

Hey guys, I got a hilo camper from 1989. It didn't come with much information so these threads have been really valuable. Me and my dad are basically taking the whole side off and replacing, we also did replace a cable while we had the side off. We manually raised it with Jack's to get the wgole thing lifted one corner at a time to get to the pump and we can lift it manually now. My question is- I can lower with the switch but not lift with the switch. We thought it might be the solenoid so I got one from the manufacturer, but replaced it and nothing happened. I also tested the old beat up cable on the cable because we tested that and it was bad, but srill not raising. I am not an electrician, so I don't really know what else to look for, the wiring inside is all over the place, is there a fuse in there that would keep it from raising? My only idea I the the motor is seized up or something, so I took it out and am going to take to the motor shop tomorrow to see if they have ideas.

Kinda turning into a lot of money here and I feel like there is a lot I don't know about electricity so any ideas would be helpful. I'll post pictures.

Hi and welcome!

Seems like you're doing some good troubleshooting. The fact that it lowers tells me the circuitry to the lowering valve is good and that you have the Master Switch in the right position.

But, you're not telling me enough about what happens when you try to raise the top. Do you hear ANYTHING when you push the lift switch in? If the lifting solenoid is working, you should hear a "click". Does the lift motor run when you push the lift switch? Do you have a fully charged battery installed in the trailer? (The lift motor WILL NOT run on shore power or if the battery is low on charge.)

If you can get the top up manually, this tells me you have a good hydraulic system, so the problem has to be in the lift motor, solenoid or battery.

- Jack

Thanks Jack! There is nothing when I go to lift it, no click at all. I replaced the battery, then replaced the solenoid, still no click. My grandpa said when we tried to bypass the solenoid and the motor still didn't run that it was probably the motor, so I guess that's the next thing to try? I pulled it out, going to take it to a alternator shop and see if they can get it going, I figured it would at least make the solenoid click if it was wired correctly and getting power. The positive and negative terminals on the same side of the solenoid doesn't really make sense to me still, I guess it has power all the time but the switch is supposed to close the circuit?

Yes, the lift switch energizes an electromagnet in the solenoid that causes it to move to the "closed" position (with an audible click). That closed position completes a direct circuit from the battery to the lift motor that allows it to run to power the lift pump.

The amount of current the motor draws is VERY large, and a solenoid is a kind of heavy-duty switch that can handle that current.

If you're not hearing the click, then either the solenoid is bad, or, it is not getting current from the switch, which is my guess since you've replaced the solenoid. You could have a broken wire or bad contact from the lift switch to the solenoid. This would be the wiring in the trailer.

Here is a link to the 1990 Model Year Owner's Manual for HiLos. https://www.hilotrailerforum.com/f49/owners-manual-1990-25ft-classic-2016/
HiLo publishes a "generic" manual for all trailers each model year and there are very little changes from year to year. Your trailer should be very, very similar. There is a wiring diagram in it on page 18.

The lift circuit is in the upper diagram and it shows a yellow wire from the lift switch to the solenoid that would supply activating current. With a voltmeter, you could check this wire at the solenoid to see if it has battery power with the switch in the lift position. In the diagram, it shows 4 wires to this solenoid post. The lift switch wire, the positive battery cable, the charging wire from the circuit breaker in the tongue, and the connection to the solenoid switch (which may be internal and not visible). The negative post on the solenoid has the negative battery cable and a wire from the lowering valve.

I don't know how to tell you to identify these posts, but the alternator shop should be able to do it.

I really suspect your problem is in the trailer wiring.

- Jack

I am going to pick up the motor now, he said the solenoid that I had gotten didn't work but they hooked it to a new solenoid and it works now. Can I ask, I know the wiring is really wonky in the trauler, I'm pretty sure the last guy who had it took the converter out and put in a new breaker. Could I put in my own switch in the motor housing that controls the up function?

You CAN, but if the solenoid was bad, then it may well raise and lower with the OEM switch and I think that would be better, rather than making even more undocumented changes to the wiring.

- Jack