Transponder Wiring

#1

Just a straw poll, but I wanted to see what other people decided to do to wire in the transponder? Thanks in advance

#2

I looked for an open plug (down near your left foot) that gave 12v only when the key is on, and found the matching receptacle in my parts bin. Pulling 12v off the radio also works.
-Vic
So #325

#3

I just installed my yesterday. I mounted it inside the driver side wheel well I fished the wire through the brake line hole into the engine compartment and wired it directly into the fuse panel. I found a switched fuse to tie into and grounded it on the hood latch bolt.

I probably would have wired it into the passenger compartment and found an old switched wire to tie into but after installing my fire suppression system with 5 nozzles I was pretty much ready to be done with it.

#4

My 87 had an unused fuse block in the right rear corner of the engine compartment that looked OEM. It was switched with the ignition.

Mounted transponder to a piece of soft aluminum with a light rearward brace so that if it got hit it would fold instead of getting smashed.

Put it WAY forward…never know when it will make a difference…

#5

Great point on mounting it forward!

I mounted my data logger much the same way on a piece of alum and found an unused switched 12v. However, I put mine on the unused battery tray.

#6

the really confident ones mount it on the rear bumper B)

#7

nasaregistrar wrote:

Yeah…but…

Ask Brandon about forward placement of a transponder.

I do believe it was the only reason I beat him as we crawled to the finish line at summit point one race…he was inching by…but I got him by about 2 feet.

And I think transponder placement helped!

Mike D.s Transponder is WAAAAAYYYY up front…GO mike!!!

#8

Carlton as well…although me looking down from above the line at CMP was the deciding factor.

#9

So the rules have no say-so on placement?

#10

That’s correct. No required placement area.

I bent an aluminum bracket 90 degrees and mounted it where the A/C dryer(?) thing used to be. It left a hole in the sheet metal about as big as a beer can and the transponder/bracket went right down in it. It’s just behind the right side headlights.

Carter

#11

I placed mine as far forward as possible (the driver’s side fog light/brake duct opening) and just ran the wire along the OEM snap ties beside the air cleaner and wedged the lead under one of the ignition-switched radio fuses (number 17, IIRC).

#12

Just got finished with this - and did a bit of research that may save someone a few hours in the future.

I wanted to mount mine near where Carter did (the hole where the dryer used to be). Right next to it is the washer bottle - and I’m looking at the bottle, and see the wires for the sensor for the check control (that is unplugged under my dash) for the washer fluid. I know this should be hot when the car is running for monitoring the washer fluid. No problem. I’ll use the ground (brown) wire and the hot (Blue/Violet) to the transponder. It’s switched, so it won’t kill the battery. I hook it up, but no love. No light on the transponder.

So, off to the wiring diagrams. After crying a bit, I found the issue - as the display is not plugged in, there is no connectivity to the wiring anymore. I go to the plug that I moved from near the sunroof to under the dash, where I neatly zip tied the old wires together. I pulled the Blue/Violet one out of the connector, and the Green/White (switched power), spliced them together, and the light on the transponder goes on. Nice. I mounted the transponder near where the horn used to live - I used 4 bolts, nuts, washers and lock washers, and it’s done. I tried rivets, but I don’t have any that long.

#13

I used the washer fluid sender for my power and mounted it on the frame rail near the passenger front wheel…Isn’t finishing position based on a line of sight, not transponder score?

#14

No, finish is totally gauged on whose transponder crosses the finish line 1st.

#15

I know that T&S is watching the cars in close races at the finish line in my region …

tomzzy wrote:

#16

Carter wrote:

[quote]That’s correct. No required placement area.

I bent an aluminum bracket 90 degrees and mounted it where the A/C dryer(?) thing used to be. It left a hole in the sheet metal about as big as a beer can and the transponder/bracket went right down in it. It’s just behind the right side headlights.

Carter[/quote]

Carter,

I remounted my transponder just like this today, but i noticed that w/o the front/lower splash shield the transponder is exposed to the open wheel well. Is yours like this? Have any trouble w/ the tire kicking up debris and messing up the transponder? I’m thinking about putting a little shield around it. A project can never be too simple!

I also think i’m going to hardwire it to the distribution block on the passenger side firewall. Any idea how much current the transponder draws?

Thanks

#17

Does this car have the two accessory fuse holders mounted to the front of the fuse box? If so one provides switched power and the other unswitched power. Current draw is negligible, about 40ma.

#18

sho does and thats what i used.

I built a little shield for the transponder out of a coke can.

:blush: