Strange problem happening.

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Mar 17, 2015
Yuma, Az
Yesterday my buddy an I went for a drive out in the desert and something strange is happening with my AC when I key up the mic on my cb. First, you can hear the AC through the cb speaker but I haven't installed my filter yet so I'm worried about that. The weird part is when the AC is blowing out of the front vents then when you key up the mic the airflow changes to the defrost vents. Any ideas?

Could be RF leaking from the rig/antenna coax and coupling into the wiring that then causes the AC ECU to hickup.

Also, where did you pick up power and gnd for the rig? Best is direct to the battery.

That's what I was thinking. There's a 90 degree adapter on the back of the cb so that's probably where it's coming from but when I checked swr it was almost perfect. Like below 1. Right now the positive wire is directly on the battery and the neg is on the ground next to the battery. It's just temporary until i get my dual battery setup and mount another fuse block.
SWR can be 1:1 into a dummy load.... So, that's not really a test of whether you have RF leaking.

First step would be to verify where you routed the +/- wires out of the back of the rig since it likely all passes very close to the AC control wires. Maybe some shielding there could help. Obviously the RF coax/connector/cable and AC wiring needs to be separated too.

My HAM rig is in the rear cubby hole - the passenger side cubby in the rear storage area. Antenna's are both in the rear. +/- wiring runs along the passenger side through a grommet on the passenger side firewall and to the aux battery on the passenger side. Never had any RF issues (even 50W output) but then all of that is far from any of the AC stuff, ECU stuff etc.

Hunting RF issues can be a tricky (can't 'see' it). So, somewhat trial and error as you move things (wiring around).

In the service manual for my 94 it says to install the antenna feeder for Ham and CB radios at least 7.87 inch's away from the ECM, ECU and all sensors of the trucks electronic systems. It says not to wind the antenna feeder together with other wiring, it also says to avoid running the antenna feeder parallel with other wiring harnesses. By the feeder I'm thinking their talking about the coax cable.
That's good to know.
Also, don't coil up excess coax. Serpentine across your floor board in broad loops.
Does it say where to run it and where to mount the
Also, don't coil up excess coax. Serpentine across your floor board in broad loops.
How could I shield the cable without it looking like crap. There's only so many places you can run it. My antenna is on the front/top/passenger side light mount on my arb.
Danthman114, i see that you mounted a CB in your rig, so what I'm about to tell you won't help much with that radio. I know for a fact that some Ham radios come with a detachable face plate. With that ham radio you can mount both the Antenna, and the radio in the rear of your rig. Doing that will do away with any interference with your trucks electronics, while giving you total control over all the radios functions by mounting it's face plate, and mic on your dash. Here's a link to a real nice duel band radio. Welcome to

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