Community Forums

chasfm11 · 08-05-2022, 12:09 PM

I tried to append to a previous thread on this subject but the forum says that it is too old for that. So I'm starting a new thread.

We've had our 2018 Equinox since January 2019. I fitted it for towing myself after buying a different 2018 Equinox (AWD, gas) and discovering that it wasn't towable. I owned that car for one day and traded it on our current car. It wasn't fun.

But we towed the car for two years and more than 10K miles without issue. It worked great. Last year at the beginning of August and our return from a month in the mountains of New Mexico, we arrived home to find the Equinox's battery dead. Bummer. If have fussed with the charging circuit ever since. Sometimes it works and sometimes it runs the battery down. I completely replaced the motor home side of the circuit, wire and all. I replaced everything on the Equinox side except the wire from the front bumper (I did replace the socket on the connecting cord) and still had problems intermittently.

I had the original AGM battery and given its age, I though it might be the problem. All the dealer had was another AGM so I went with it. The charging circuit worked fine for several days and more than 1,000 miles. Problem solve.... well not quite.

We drove the Equinox around for a month. When I hooked up again, the charging circuit was not working again. By "not working", I mean that whatever it was putting out was not enough current to overcome the drain from the Equinox systems. I have the origin of the circuit on the motor home side tied to a fuse panel (its own circuit) that is fed by both the engine alternator and the converter. I turned on the generator (which kicks on the converter) and arrived home with a fully charged Equinox battery. I have a voltage monitor on that battery and it had been as low as 73% charge and 12.3 volts only 6 hours earlier.

I'm confounded. I can see that the output voltage from both the converter and the alternator is 13.9v+, each tested separately. When I measure the voltage at the Equinox battery, it was never above 12.6 when the failure was happening. The last part of the trip home showed that voltage at 12.9. Assuming that alternator was putting out 13.2v around that time, the .3volt drop is what I would expect - not more than a volt and quarter. I changed nothing from when the Equinox charging line was working until it wasn't. All I can figure is that something else in the Equinox is at least intermittently drawing more current. I carefully checked that it wasn't the lights and even shut off the audio. No difference.

If anyone has any troubleshooting ideas, I'm all ears

Thanks

Charlie

lllkrob · 08-05-2022, 01:45 PM

Are you using a charging system box like RVi? I seem to remember they require 2018 and later Equinox owners to remove the fuse for the rear wiper. This kills power to a computer that draws a lot of current while towing. Might be your problem.....

chasfm11 · 08-05-2022, 04:29 PM

I used all Roadmaster parts in preparing the Equinox for flat towing. They have two "kits" for the charging line, one for the motor home side and one for the toad side. I installed both per their instructions.

I queried the dealer about pulling fuses. They have no guidance about what is in the owners manual - which says nothing about pulling fuses. I'm thinking that if it were a design flaw, it wouldn't have lasted a couple of years without problems.

NXR · 08-05-2022, 06:20 PM

If you have adequate voltage at the motorhome but not at the car's battery it either has to be a voltage drop on the 12 volt power line or the ground line, or both. Both have to be an adequate gauge size.

Since you have a voltmeter, connect the car to the motorhome and put the car into towing mode.

Then put one meter lead on the car's NEGATIVE battery terminal and the other meter lead on the MOTORHOME's chassis. You should see well under 1 volt.

Do you turn the automatic headlight function off each time you set the car up for towing? If not, any chance the car's headlights are coming on while you're towing?

Ray