Bracket Talk
Diode connection tips

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https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1777076107

June 15, 2024, 10:42 AM
Ron Gusack
Diode connection tips
A couple years ago I posted a problem with a t-brake stumble and Mark schooled me about adding a diode to eliminate flyback voltage. This is an internal solenoid brake in a 400 trans. What's the proper way to install a solid wire diode to a stranded wire under a vibration prone race car? I've been told Wago lever and lots of tape, sounds sketchy to me. I'm not very good with solder, but if that's the ticket I'll give it a go.
June 15, 2024, 03:29 PM
camaro77
strip wires back twist and solder heat shrink it and be done if you are not comfortable with solder you could butt connect it but I would still heat shrink it.
June 15, 2024, 05:15 PM
Big Steve
^^^THIS^^^
June 15, 2024, 07:19 PM
markemark
I use a non-insulated connector to go from a solid wire to stranded. I’ll crimp, then tin it slightly through the center stop hole. Heat shrink it and identify the band end.


June 16, 2024, 04:50 AM
SP 124X
I've stopped using butt connectors in general. I use non insulated parallel connectors for all multi wire connectors and diodes. As for heat shrink I use thick glue lined clear stuff on my diodes.




Denis LeBlanc

June 17, 2024, 10:13 AM
Ron Gusack
Thank you for all the advice. I always thought crimping solid wire wasn't advisable. I'm thinking about using a Dorman 85412 adapter to attach 2 spade terminals to the one for the t-brake pass through. Is that acceptable? Is it okay to run about 14 feet of 14ga wire from the diode to the battery ground? Thanks again!
June 17, 2024, 10:52 AM
Busted Knuckles
And make sure you put it in the right direction...I'd do something simple and easy but not permanent first, then test and if it's good, solder and heat shrink.


Organized people are just too lazy to look for their $h!t.
June 17, 2024, 12:47 PM
markemark
quote:
Originally posted by Ron Gusack:
Is it okay to run about 14 feet of 14ga wire from the diode to the battery ground?


Why 14' ? Does internal TB have one or two wires coming out of case?
June 18, 2024, 08:16 AM
Ron Gusack
quote:
Originally posted by markemark:
quote:
Originally posted by Ron Gusack:
Is it okay to run about 14 feet of 14ga wire from the diode to the battery ground?


Why 14' ? Does internal TB have one or two wires coming out of case?

The brake is grounded to the trans, so only one wire. I understood your advice to mean the proper way to ground the diode was to go directly to the battery post. I think I already have 4 grounds going to that post. 14' was a rough guess with confidence that it couldn't be more than 14. By the time it goes through the floorboard, across to the passenger side, up and over the roll cage, through the rear firewall to the battery, I might be 10 to 12'.
June 18, 2024, 09:02 AM
markemark
quote:
Originally posted by Ron Gusack:
The brake is grounded to the trans, so only one wire. I understood your advice to mean the proper way to ground the diode was to go directly to the battery post. I think I already have 4 grounds going to that post. 14' was a rough guess with confidence that it couldn't be more than 14. By the time it goes through the floorboard, across to the passenger side, up and over the roll cage, through the rear firewall to the battery, I might be 10 to 12'.


If one wire, attach band end of diode to TB solenoid positive at case and ground the other end of the diode directly to the trans case. The transmission case is grounded through the engine. That internal TB solenoid is grounded to the case.

I ground my th400 TB solenoid and attached diode directly to the bolt that holds the solenoid bracket in place.
June 18, 2024, 10:26 AM
Eman
What he said. On my car I have a battery cable running the length of the car for negative and direct connection to it at the firewall.
June 19, 2024, 10:05 PM
Hookdaddy
https://painlessperformance.co...e-car-part-no-80111/

Painless sells this one. I use it on my dragster


Don Scholl, S&W Race Cars - retired
“Don't pick a fight with an old man. If he is too old to fight, he'll just kill you.”


June 20, 2024, 10:28 AM
Ron Gusack
I checked the spade coming out of the trans case before installing the diode splice and I have continuity from the spade to the case. The spade shouldn't be grounded should it?
June 20, 2024, 10:35 AM
Ron Gusack
I checked to see if the spade coming out of the case was grounded before I installed the diode splice, and it is. Does that mean the brake solenoid is screwed up?
June 20, 2024, 10:40 AM
Eman
You're measuring through the coil of the solenoid to ground, if it was open it would mean the solenoid was no good.
June 20, 2024, 12:03 PM
Ron Gusack
quote:
Originally posted by Eman:
You're measuring through the coil of the solenoid to ground, if it was open it would mean the solenoid was no good.

Thanks!