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B&M MegaShifter Relay (275-206) Burning out fix

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Old Jun 3, 2013 | 11:42 PM
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B&M MegaShifter Relay (275-206) Burning out fix

Theres a few members who have had problems with their 275-206 relay, which is what B&M recommends. This relay will most likely burn out because there is a thin white wire that is triggered to pass a 12 volt current from the ignition switch to the relay, and down to the starter. The white wire is so thin that it will burn out because of the amount of current flowing through it. Its very similar to a fusible link. The pictures below will show you my relay that burnt out 2x's. The first time I re-soldered another white wire in place. But it burnt out too. So I then re-soldered another thicker gauge wire. Be advised that you must have a soldering iron that is capable of producing heat at least 350-400* F. Today I tested the relay and it never got hot at all. So I say mission accomplished. if you have any questions, let me know and I will help you out or explain what I did to make this junk relay work.

Below is a timeline of events of my progress to the successful solution to the relay.

First burnt wire
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Re-soldered new wire
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Replaced wire burnt out again.

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And now the thicker gauge wire that I soldered in place of the thinner wire.

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Old Jun 5, 2013 | 02:11 PM
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Re: B&M MegaShifter Relay (275-206) Burning out fix

Forgive me if I am misunderstanding this,
But the whole point of a relay is to relieve the "comfort" switch of a high current load. You could flip a switch that would handle the current draw but who wants to flip a breaker sized switch?
That being said, who would design the main (power bearing) circuit of a relay with a wire inline only capable of handling minimal loads? Especially in a starter circuit?
Are you sure its not hooked up wrong?
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Old Jun 5, 2013 | 04:33 PM
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Engine: 350 Tuned Port Injection, for now.
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Axle/Gears: Posi - 3.23
Re: B&M MegaShifter Relay (275-206) Burning out fix

Like I said in the header. B&M recommends, not provides, recommends that said relay, which is from RadioShack. Some cars for some reason won't burn up the white wire. There are many members who have experienced this issue and simply do without the relay. Yes it is hooked up properly too. I don't know why B&M recommends a relay that has terminals that can handle a messily 3-5 amps while the starter can see 25+ amps. This thread just covers a little bit of my experience. Check my profile and look at some of my recent threads. You will find that I burned up the original white wire and the resoldered new wire too.
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Old Jun 5, 2013 | 07:03 PM
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Axle/Gears: G92 J65 3.27
Re: B&M MegaShifter Relay (275-206) Burning out fix

The starter its self will draw close to 200A.
3A to contact the solenoid doesn't leave any wiggle room.

What are all the prongs for on the relay? Why so many?
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Old Jun 5, 2013 | 08:49 PM
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Engine: 350 Tuned Port Injection, for now.
Transmission: 700R4
Axle/Gears: Posi - 3.23
Re: B&M MegaShifter Relay (275-206) Burning out fix

Originally Posted by Keoman
The starter its self will draw close to 200A.
3A to contact the solenoid doesn't leave any wiggle room.

What are all the prongs for on the relay? Why so many?

The starter draws 25 - 35 amps, not 200A.

According to the Radioshack packaging, the relay has a 5A rating for the prongs.
There are so many prongs on the relay because, well, its a relay.
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Old Jun 5, 2013 | 08:50 PM
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Engine: 350 Tuned Port Injection, for now.
Transmission: 700R4
Axle/Gears: Posi - 3.23
Re: B&M MegaShifter Relay (275-206) Burning out fix

http://www.aeroelectric.com/articles/strtctr.pdf

page 2, paragraph 5
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Old Jun 10, 2013 | 04:36 PM
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Starting To Go Wrong

The starter SOLENOID draws about 30 amps.

The starter draws about 200 or more amps.


Happy Racing!



Rule Number 1 Is To Know Which Rules You Can Break

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Old Jun 10, 2013 | 07:16 PM
  #8  
Chevy86 IROC-Z's Avatar
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Engine: 350 Tuned Port Injection, for now.
Transmission: 700R4
Axle/Gears: Posi - 3.23
Re: B&M MegaShifter Relay (275-206) Burning out fix

Ok. The wire in focus draws 25-35 amps (solenoid). I'm not worried about the starter current draw.
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