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> Now what? Fuse on relay board blowing., rear fuse that controls fuel pump blowing
Phoenix914
post Dec 30 2007, 05:42 PM
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Last night I tried to start my 914 to move it out of the garage...and it didn't start. When I turned the key, the auxiliary fan came on because the lever was pulled back. I turned off the fan, then proceeded to start the engine and it just cranked. I turned off the key, then turned it to the on position. This was when I noticed the fuel pump didn't come on. Why? During my check I discovered the rear fuse of the two on the relay board in the engine compartment was blown. A little research told me that this fuse is for the fuel pump and aux. fan.

So, I disconnected the fuel pump, put in a new fuse and it blew when I turned the key. Another new fuse, reconnected the fuel pump, disconnected the aux. fan, turned the key and the fuse blew again. It's not the fan. What is causing this? I drove the car in there less than two weeks ago!!

It's strange that the aux. fan came on the first time I turned the key. Now it won't work with the fuse blown.

Somebody please help me. I have to move everything out of this rented garage tomorrow. This includes my 914. I'd rather not have to tow it if that can be avoided.
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SirAndy
post Dec 30 2007, 05:48 PM
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fix the short ...


it's probably the aux. fan and/or switch.

disconnect the fan first, look for obvious signs, like cracked/exposed wires.

also, the connector on the switch is dangerously close to ground and can easily shorten out. unbolt the switch and test with switch removed.

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McMark
post Dec 30 2007, 05:53 PM
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It's the wire that powers the AAR. It's shorting out.
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Phoenix914
post Dec 30 2007, 05:53 PM
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OK. I'll take the switch out. I figured disconnecting the fan wiring back at the fan would take it out of the equation, but maybe that's not enough.

Thanks.
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SirAndy
post Dec 30 2007, 05:57 PM
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QUOTE(McMark @ Dec 30 2007, 03:53 PM) *

It's the wire that powers the AAR. It's shorting out.


forgot about that one. that's on the same circuit as well ...
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Phoenix914
post Dec 30 2007, 05:59 PM
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Cool. Where the heck is it? (IMG:style_emoticons/default/sad.gif)
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SirAndy
post Dec 30 2007, 06:00 PM
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QUOTE(Phoenix914 @ Dec 30 2007, 03:59 PM) *

Cool. Where the heck is it? (IMG:style_emoticons/default/sad.gif)


red wire, going to the AAR ...

post a pic of your engine bay!
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McMark
post Dec 30 2007, 06:02 PM
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White wire that comes out near the distributor. It's in the same bundle as the tach wire (black/purple), coil wire (black), and oil pressure switch wire (green/red).
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SirAndy
post Dec 30 2007, 06:03 PM
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QUOTE(McMark @ Dec 30 2007, 04:02 PM) *

White wire that comes out near the distributor.


huh? on my '70 1.7L, the wire was red, not white ...
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Phoenix914
post Dec 30 2007, 06:09 PM
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This is the only pic I have right now, and it sounds like it's from the wrong side. I'll head over to the garage now and check out the wires. Which is the AAR? That would help me, regardless of the wire color.Attached Image

Sorry, forgot the image.
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McMark
post Dec 30 2007, 06:16 PM
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Andy, it might be red on the early cars.

The AAR is the canister that mounts right near the air box and has two largish air hoses, one coming from the filter housing the other going to the plenum.
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Phoenix914
post Dec 30 2007, 06:23 PM
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Ok, thanks. I'm off to see if I can fix it. I'll report back later. (IMG:style_emoticons/default/beer.gif)
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Spoke
post Dec 30 2007, 07:14 PM
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You could try removing both relays for the fan and the fuel pump and see if the fuse still blows. If it does, it's probably not either of those. If the fuse doesn't blow, replace one at a time to isolate the issue.

Disconnect the fan and fuel pump and check.

I doubt it's the fan switch by the shifter since it grounds the negative side of the relay thus even if shorted to ground, will not cause a short.

Spoke
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JeffBowlsby
post Dec 30 2007, 07:16 PM
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Its a red wire coming out of the AAR (all years), connecting to a white wire on the ignition harness with a long single pole box housing.
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Spoke
post Dec 30 2007, 09:34 PM
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What is an AAR? I've seen AAR several times. All American Rejects, that is. They rock (IMG:style_emoticons/default/aktion035.gif)

Spoke
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McMark
post Dec 30 2007, 10:47 PM
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Auxiliary Air Valve, basically it's a controlled air leak to keep the idle high while the motor is cold.

Jeff, thanks for setting us straight. (IMG:style_emoticons/default/thumb3d.gif)
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McMark
post Dec 31 2007, 11:03 AM
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Wellll............ (IMG:style_emoticons/default/unsure.gif)
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Dr Evil
post Dec 31 2007, 01:31 PM
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Common gremlin, I even made a schematic (IMG:style_emoticons/default/biggrin.gif)


Attached image(s)
Attached Image
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Phoenix914
post Dec 31 2007, 03:04 PM
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QUOTE(Jeff Bowlsby @ Dec 30 2007, 08:16 PM) *

Its a red wire coming out of the AAR (all years), connecting to a white wire on the ignition harness with a long single pole box housing.



This is exactly what I found. The wire didn't appear to be grounding anywhere. When I unscrewed the AAR from it's base, the fuse did not blow, the fuel pump worked, and the aux. fan worked. Reattach the AAR to it's base and the fuse blows. Is the AAR itself bad, grounding internally?

I just left the wire disconnected and drove it home. Idle stayed high, but it ran fine.
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SirAndy
post Dec 31 2007, 08:30 PM
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QUOTE(Phoenix914 @ Dec 31 2007, 01:04 PM) *

Is the AAR itself bad, grounding internally?


yupp, the AAR grounds through the engine case. if the fuse blows, the AAR is broken ...
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