2001 Mazdz B2500

[ai8o]

I am going to install a VHf/Dual band mobile in a 2001 Mazda B2500.

Can I connect the negative power lead directly to the battery?
Does anyone know if there is a Hall Effect sensor in the truck?

I looked in the owner manual and the service manual; neither says anything, one way or another.

 

[mmckenna]

Best way to check is to visually inspect the negative lead coming off the battery and going to the frame/chassis/engine block. If there is a hall effect sensor, it will probably be pretty close to the battery.

Those were essentially rebadged Ford Rangers. You could probably find a wiring diagram for a similar model year Ranger and check. But I'd be surprised if there is one, I don't remember those really showing up until a few years later.


But it's still a really good idea to not connect directly to the battery there. It will create a path from the antenna mount/radio chassis back to the battery for any voltage that doesn't find a path through the ground strap at the battery. Corrosion at the battery, damage to the ground strap, corrosion at the point where it attaches to the body can result in the radio negative lead becoming the path. Plus, keeping your negative lead short gives you a shorter path to ground for any undesirable noise at the radio.

 

[KK6HRW]

Best way to check is to visually inspect the negative lead coming off the battery and going to the frame/chassis/engine block. If there is a hall effect sensor, it will probably be pretty close to the battery.

Those were essentially rebadged Ford Rangers. You could probably find a wiring diagram for a similar model year Ranger and check. But I'd be surprised if there is one, I don't remember those really showing up until a few years later.


But it's still a really good idea to not connect directly to the battery there. It will create a path from the antenna mount/radio chassis back to the battery for any voltage that doesn't find a path through the ground strap at the battery. Corrosion at the battery, damage to the ground strap, corrosion at the point where it attaches to the body can result in the radio negative lead becoming the path. Plus, keeping your negative lead short gives you a shorter path to ground for any undesirable noise at the radio.

Could you expand this answer as to what WOULD BE the best way to connect the negative lead from a mobile radio (Yeasu FT-7900) to its host vehicle?

 

[mmckenna]

Could you expand this answer as to what WOULD BE the best way to connect the negative lead from a mobile radio (Yeasu FT-7900) to its host vehicle?

Ground it to the sheet metal near the radio. This lets the hall effect sensor do it's job on the newer vehicles.
Having a short path to ground can also help with RFI and other annoying issues.

 

[03msc]

Matthew isn't wrong at all, don't mistake this statement as me implying that, but another suggestion I see a lot is to run the neg/ground to the grounding point of the vehicle battery. Not to the battery negative post but to where the negative cable attaches to the vehicle chassis. Again, mmckenna is giving good advice, too, and it's often easier to do what he suggested if you're installing one radio. But if you're running a single line from the battery back to, say, a bus bar or powerpoles strip (like a RigRunner or something) you'd connect to the chassis at the battery grounding point. Or that's what I've seen suggested many times.

 

[mmckenna]

I've got a stack of 8-9 100 watt VHF MCS-2000's sitting in my garage right now. All of them came from the factory with 8 gauge power cords. The positive lead is about 17 feet long with the fuse/ring terminal at the battery end. The negative lead comes about 2 feet long for local grounding.


If you want some really good reading on well thought out radio installations, the California Department of Transportation (CalTrans) has a really nice document:

Electrical | Caltrans

State of California

dot.ca.gov

Section 17 covers two way radio installation, but there's some excellent mobile wiring guidelines in the other sections.