Remote start in a 24v vehicle

I'm trying to install a remote start into a heavy-duty truck with a 24volt electrical system (2 12-volt batteries wired in series). This truck has an automatic, so no worries about that. It also has a 12-volt power outlet which I believe gets constant power. So far I've got two ideas: 1. Find an RS unit designed for 24-volts (no luck there yet). 2. Use a 12v RS with external relays, running the power and ground to the 12v power outlet, and making sure that the non-coil contacts on the relays are the only ones that see 24v. Here I'm not sure about what kind of relays I'd have to use though. Any suggestions on all this?C Renner's Auto Electronix

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Yeah i think you have the right idea with using the relays to push your 24V to the Ignition, Accessory and Starter. Everything else should work like it's supposed to. If you need you can go all the way back to the first battery with your fused power feed for the remote start brain for 12V. Sounds like an interesting project. My cousin is building a house and mentioned the other day he wants me hook up remote starter to his electric start generator. So he doesn't have to climb down off the ladder everytime he wants to run it and won't have to listen to it when he doesn't need it. LOL I said yeah I'm sure i can figure something out. Might have to put an actuator to choke it when it's cold.

Well, what are the differences in tach/voltage sensing? Are you going to be able to work around that?Certified Security Specialist

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I don't think there will be too much problem with using voltage sense, unless the 12-volt supply is regulated. I guess in that case I'll just have to run the power and ground straight to the battery box. I'm concerned about the relays though. They don't need to be high current - the ignition switch wires are fairly small gauge, but they will have to not arc when switching the 24 volt wires, and also be able to activate with the 12 volt supply. Any ideas where I could find some that meet that spec? I took apart my regular SPDT relays yesterday and there is only like 1/16" between the NO and NC contacts.C Renner's Auto Electronix

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what year and make for your truck

Okay...I've found that radio shack has relays that can do the job. I'll give them a try and let y'all know how it goes.C Renner's Auto Electronix

My service is cheap, quick, and good - pick any two