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Posted by: Mark Henry Aug 17 2017, 11:46 AM

For my /6 conversion with relay board delete.
Does the factory rear window defogger have a relay?
Or is it just a plug in with a fuse on the board?

Also what size is the fuse?

If it's just a fuse I'll jump it with an in-line fuse. I know it was working.

Thanks

Posted by: Jeff Bowlsby Aug 17 2017, 12:06 PM

Both fused and relayed. Check the schematics.

Posted by: Mark Henry Aug 17 2017, 12:11 PM

Thanks, adding a relay would be easy enough.

Posted by: Jeff Bowlsby Aug 17 2017, 12:15 PM

Stock round relay on the stock relay board. Doesn't get simpler than that.

Posted by: Perry Kiehl Aug 17 2017, 12:53 PM

I think per his original post the relay board was deleted.

Mark, there's a 944 rubber boot that fits over the Bosch square mini relays, I'll see if I can find the PN

Posted by: Mark Henry Aug 17 2017, 04:42 PM

Yep, 1974 914-6 conversion with webers, MSD, no relay board.
Eventually I"ll have to add a relay to keep the defog, but it's low on the priority list.

Next question, the Black/red wire for the fuel pump, I know that would have triggered a relay, but when I check it (key on) there's no power (or ground) to trigger a relay.

I know I can just take power from the switched power.

Posted by: Perry Kiehl Aug 17 2017, 07:51 PM

If the relay board was taken out there won't be anything connected to the fuel pump wire, it gets power via relay on the board.

Posted by: Mark Henry Aug 18 2017, 06:53 AM

I realize that it wouldn't have proper (amps) power, but I know how a relay works, I expected this wire (main harness T13, fuel pump, black/red) to provide one of two ways of switching.

a/ switched power on (ignition key)
b/ switched ground to provide continuity to complete a circuit. If it works this way I know it would have been getting power from the board.

A relay needs two power sources, one would be the external (ignition key) switched circuit which would be low amp power (or continuity) to activate the relay and the other the high amp circuit (pump) switched by the relay.
The wire has to do something.

For now it's no matter, I can get switched power for the pump from the keyed on to the MSD.
In the future I'd like to install a fuel pump relay, that shuts off the pump if the engine quits running but still has power.

Now I just have to get some of my extra gauges working (oil temp,pressure, WB O2 and Cyl head temp), set the timing and then I'm getting damn close to turning a key.

Posted by: Mark Henry Aug 18 2017, 09:05 AM

Just an FYI how I hooked my conversion engine harness into the cars main harness.
You can also see the defog pigtail just above it.
The connectors below it are the blower, correct?


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