Another Ignition Switch Question - GT500 (1976)

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Tailchaser1960
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Suzuki 2-Strokes: GT500 1976

Another Ignition Switch Question - GT500 (1976)

Post by Tailchaser1960 »

Hi, I've just acquired a 1976 GT500 (A?) and it has some electrical issues (more of that in later posts after searching) but the 1st one concerns the ignition switch which looks to be a pattern part. The switch has 4 wires (Red, Orange, Grey & Brown). Looking at the wiring diagram(s) am I correct in thinking that in Pos 1 (On) the Red & Orange should be connected and the Grey & Brown should be open circuit and in the off position the Red & Orange are O/C and the Grey & Brown are connected?

The switch that is on the bike had both Red & Orange and Grey and Brown connected in the On position (both are O/C in the off position).

Cheers,

Jeff
Suzuki GT500 A 1976, Honda CB750 Nighthawk, Honda CBF500
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jabcb
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Re: Another Ignition Switch Question - GT500 (1976)

Post by jabcb »

That's correct.
Red is hot from the battery. Orange is power for the bike.

The GT500 has a PEI ignition. It's a pointless magneto CDI ignition. Self powered & doesn't connect to the battery.
The other two switch wires ground out the ignition system so the bike doesn't run.

The right handlebar on/off switch also grounds out the ignition.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Tailchaser1960
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Suzuki 2-Strokes: GT500 1976

Re: Another Ignition Switch Question - GT500 (1976)

Post by Tailchaser1960 »

So, when the switch is in the ON position the Grey & Brown wires should not be connected as this would ground out the ignition circuit?

If this is the case then I think I need a new switch.

Cheers,

Jeff
Suzuki GT500 A 1976, Honda CB750 Nighthawk, Honda CBF500
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jabcb
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Re: Another Ignition Switch Question - GT500 (1976)

Post by jabcb »

Correct.

Looks like you have an ignition switch for a T500. An easy mistake by whoever did it.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
karl pa
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Re: Another Ignition Switch Question - GT500 (1976)

Post by karl pa »

The GT500 ignition switch is model specific in the GT line. All other GT models have the incorrect contacts.
The Suzuki X7 may use similar.
76 GT185
77 GT250
77 GT380
76 GT500
73 GT550
73 GT750
74 GT750
71 T250 scrambler
75 T500 cafe
Tailchaser1960
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Suzuki 2-Strokes: GT500 1976

Re: Another Ignition Switch Question - GT500 (1976)

Post by Tailchaser1960 »

Looking at the pattern switches that are for sale on-line, I see that some of the GT500 ones have a single 4 way block connector and some have the 4 way and an additional 2 wires with bullet connectors.

My wiring diagram only shows 4 wires coming from the ignition switch so I'm guessing that the 6 wire one is a regional variation?

Cheers,

Jeff
Suzuki GT500 A 1976, Honda CB750 Nighthawk, Honda CBF500
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jabcb
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Re: Another Ignition Switch Question - GT500 (1976)

Post by jabcb »

GT550 has a 6 wired ignition switch.
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Tailchaser1960
On the street
Posts: 16
Joined: Tue Jul 30, 2024 10:36 am
Country: England
Suzuki 2-Strokes: GT500 1976

Re: Another Ignition Switch Question - GT500 (1976)

Post by Tailchaser1960 »

Yes, I know the GT550 has a 6 wire switch but my question is about a GT500


Does anyone know where to get a proper 4 wire GT500 ignition switch from that doesn't short the Black/Yellow and Blank/White wires in the ON position. I've bought (and returned) 2 from ebay as they both shorted these wires in that position.
Suzuki GT500 A 1976, Honda CB750 Nighthawk, Honda CBF500
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jabcb
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Re: Another Ignition Switch Question - GT500 (1976)

Post by jabcb »

Looks like the GT500 ignition switch is currently available from Suzuki in the US. One of the dealers I use lists it as in stock.

Am in the US & don’t know which UK Suzuki dealers have online parts ordering.

Looks like CMSL in the Netherlands has it.
https://www.cmsnl.com/suzuki-gt500-1976 ... 711025319/
BAS (Bike Acquisition Syndrome) - too many bikes but have room for more

Suzuki:
GT750 2x75
GT550 72 & 75
GT380 72
T500 69 project & 73 project
T350 69 & 71
Honda 85 CB650SC & 86 CB700SC
09 Triumph Bonneville SE
Tailchaser1960
On the street
Posts: 16
Joined: Tue Jul 30, 2024 10:36 am
Country: England
Suzuki 2-Strokes: GT500 1976

Re: Another Ignition Switch Question - GT500 (1976)

Post by Tailchaser1960 »

Thanks to all; managed to get a new switch (along with a few other bits) from Webike in Japan.
Suzuki GT500 A 1976, Honda CB750 Nighthawk, Honda CBF500
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