bigbrdf250

iTrader: (2)

So I installed my 2 step in with my trans brake w/o any relays, I just spliced in to the power wire after the momentary that's switched to 12v. It worked for a few test runs and then stopped working. Looks like I either messed it up or had a unit fail on me. the led light stayed lit saying it was activated but neither the trans brake or 2 step worked.

Either way a new one is being sent so how do I go about installing it? I think it would work this way but not sure if I should try another way cause I had a bad unit or I wired it wrong??

It's an msd 8733 and is activated by just a 12v source or ground circuit.

3fingas

iTrader: (16)

Activation switch to trip a 12v/20a relay, power leg (87) to trans button, button to Brake/2step.

Ed Wright

iTrader: (1)

You think not having a relay caused the Trans brake solenoid to fail? How? Too much load might damage the button, not the solenoid. I don't know of anybody using a relay for that. What kind of button?

3fingas

iTrader: (16)

I don't know why it failed but that's the way to wire it. You use an activation switch to avoid unintentional engagements.

Ed Wright

iTrader: (1)

Yes, you need a switch to activate it. I'm wondering why somebody thinks it needs a relay. Most guys, where I race, use an adjustable button to adjust our lights on a given day. No relays allowed. Has to be an approved button, wired direct. Can not imagine why anybody would think a relay is needed anyway.

RENE'S RAGE

iTrader: (96)

No relay need, just slows down reaction time.
Like Ed said, probably the button gone bad.
The 2step and TB are two separate components.

bigbrdf250

iTrader: (2)

It's a hurst pistols grip with activation button.
Well the way I wired it getting power for activation was spliced into the trans brake wire that also gets activated when switch is pressed. I just don't know if it was a bad connection or bad unit all in all.

Ed Wright

iTrader: (1)

The button on the shifter handles are normally used for the line lock. Trans brake is normally a different, higher amp button.

RENE'S RAGE

iTrader: (96)

See if your button is good.
You can OHM it out, if you have a OHM meter.
Or if you have a test light or dc voltmeter, just put 12volts to one side of the button and see if you have 12 volts coming off the other side.

bigbrdf250

iTrader: (2)

My other question was should my power wire to the trans brake when not engaged have continuity to ground??
Switch not pressed red wire = has continuity to ground
Switch depressed red wire switches over to 12v activates power side of tb solenoid

Is this right??

RENE'S RAGE

iTrader: (96)

There is a possibility that it could read to ground, by going through the solenoid windings,
because the other side of the solenoid is grounded.
I would unwire the tb and button and read and see
If your getting continuity between the solenoid.
Also see if your getting continuity through
The button when it is pressed.

Ed Wright

iTrader: (1)

One wire from the button to 12 volts. Other wire from the button goes to the power wire on the Trans brake solenoid. Other wire on the Trans brake solenoid goes to ground. The wire from the button to the solenoid also goes, if you have a 2 step, to the 2 step terminal on your MSD box. It's only on while the Trans brake button is pressed. Simple.

subhumanzz

iTrader: (46)

I've had mine wired without relays for a couple years and never have had a problem.

bigbrdf250

iTrader: (2)

That's what I thought, so that's how I wired it.

Oh and one more thing that can be of great importance... It's a PRO TREE BRAKE on a th350 so maybe the wiring could be different??

subhumanzz

iTrader: (46)

It should be wired as laid out in your quote.

93camaro_zzz

iTrader: (13)

I have my transbrake button wired to that same hurdt button on top like you. It is made for transbrake use, I know that. It is even labeled in the directions as a transbrake switch. I haven't had a problem with mine yet, but I also don't have my 2 step hooked up in the car yet.

bigbrdf250

iTrader: (2)

Ur right trans brake solenoid power wire is making ground when button is not pressed.
Is that normal or how do I fix that??
Could that be y my box went out or just a coincidence?
After hooking my new box up its working just don't know for how long.

RENE'S RAGE

iTrader: (96)

I think what's it doing is reading between the coil windings in the tb solenoid.
Which would be normal.
I'll ohm mine out tonite and see what kind of reading I'm getting.
It seems like you had it wired right the first time.
You do have a fuse protecting the tb hot wire don't you.

bigbrdf250

iTrader: (2)

It does have an inline fuse. Check on that for me would u, thanks guys for y'all's help thus far.

3fingas

iTrader: (16)

I use a relay cause I'm not pushing 20 a through a toggle. As far as slowing reaction time. You tell me how much it's slowed. Lol