Firstech T-Harnesses

Vehicle-specific T-harnesses that plug in between your vehicle's factory connectors and the control module, so most connections are made by pushing plugs together instead of cutting and soldering wires. The install goes faster, and your factory wiring is left largely as it was built.

These harnesses only work with this brand's control modules, and each one is made for specific vehicles. Check both before you order.

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Firstech T-harnesses

Vehicle-specific harnesses for Compustar remote starters and security systems, sold under the FTI part numbers — Firstech being the parent company behind Compustar. They plug in between your car's factory connectors and the module, so most connections are made by pushing plugs together rather than cutting and soldering.

Reading the part number

After FTI comes the platform code, then the generation. HD is Honda and Acura, TL is Toyota and Lexus, MA is Mazda.

The generation number matters as much as the make. An FTI-HDP6 and an FTI-HDP7 are both Honda harnesses for different years and connectors.

You'll also find the FTI-SPTS anti-theft harnesses in this family. Those do a different job: they disable the push-to-start button while your alarm is armed, so a relay-attack thief with a cloned signal still can't drive away.

Which one fits my car?

Don't order by part number. Search your vehicle and we'll show you the complete solution we'd install ourselves, with the correct harness already matched to the module.

A harness is an accessory — you also need a Compustar control module, and if you're starting from scratch a plug and play kit bundles both and works out cheaper.

See all T-harnesses, or call us on 647-439-4485.

Different module? Pick its brand

Each brand's harnesses only work with that brand's control modules.

Starting from scratch?

A T-harness is an accessory, not a remote starter. It has no electronics of its own, so you also need a control module, and on most vehicles a bypass. A plug and play kit bundles the module and the correct harness for your vehicle, and works out cheaper than buying them separately.

See plug and play kitsSearch your vehicle

Know before you buy

A few connections are still made by hand

On most vehicles a T-harness removes the bulk of the splicing, not all of it. Expect a few connections to be made by hand, and plan for a bypass module if your remote starter doesn't include one.

See bypass modules

Installed or shipped

Have us install it at our Markham shop, or order it and install it yourself.

Installed in Toronto

Book an appointment and we do the whole job: module, harness, programming, and a clean, hidden install by technicians who've been doing this since 2003. Every install is backed by our lifetime installation warranty. Remote starter installation from $280.

Request an installation

Shipped for DIY

Order the kit and we pre-program it to your vehicle before it ships (most vehicles). Wiring diagrams included, and real people on chat, email and phone when you're under the dash. Free shipping on orders over $200.

How DIY support works

Common questions

Which T-harness do I need?

It depends on your vehicle and your control module. A T-harness is matched to both, so the same vehicle can need a different harness depending on which remote starter goes in. Don't guess from the part number: search your vehicle and we'll show you the complete solution we'd install, with the correct harness already matched.

Is a T-harness a remote starter?

No. It's an accessory with no electronics of its own. You also need a control module, and on most vehicles a bypass. If you're starting from scratch, a plug and play kit bundles the module and harness together and works out cheaper.

Does a T-harness mean no wires are cut?

Not quite. It removes the bulk of the splicing, but on most vehicles a few connections are still made by hand.

Does a T-harness lower the installation price?

No. Our installation price is the same as it is for a hardwired system. What you get is fewer cut wires in your vehicle.

Does it void my warranty?

No. Adding a remote starter doesn't cancel your factory warranty. A dealer can only decline a specific claim if they can show the installation caused the fault, which is why install quality matters and why we back ours for life.

Can I use one brand's harness with another brand's module?

No. Each brand's harnesses are made for its own control modules: iDatalink for iDatastart and Compustar DC3 and DC-X, Fortin for EVO-ALL and EVO-ONE, and Firstech for Compustar CM7 and CMX.

Not sure which harness you need?

Tell us your year, make, model and trim, and which remote starter you have, and we'll tell you which harness you need.

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