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Fuel Pump goes on with headlights


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Have a weird problem

 

I have a 1993 Subaru Loyale, I EJ swapped it then found a GL with a dual range and transferred everything over. 

Got a new wiring harness because I had cut the old one up and am converting the Loyale back. Everything is back together but the issue is the fuel pump only goes when the headlight switch is on and it runs constantly. Normally it would cycle when you turn the key to on. It no longer cycles it just doesn't run unless I turn the headlights on.


I'm lost I have no idea how something like this happens. 

Edited by jread
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The headlight relays and fuel pump relay are side by side under the dash.  I suspect you have miswired the fuel pump relay to the headlights.  Was the harness from another Loyale, or an older model?

 

Is this the Loyale for sale on Craigslist in North Van?  Your avatar picture looks similar, but white wagons are common.

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Sounds like "Roadkill" have been at your car in the past :P

 

What year model was your donor harness from?

I was under the impression that the dual range over there became very scarce after 87 (which is when Subaru did a facelift & major wiring change). But this is also the same time that the carb engine disappeared, so it'd be difficult to wire up your later model engine :P

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Ok. 

So more news today. Pretty sure the running lights aren't working but the headlights are. Not really sure why these two are related though! 

I don't think its a short something must be plugged in wrong. Could the pinnouts be different on the large connectors from one year to another?

Edited by jread
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If that harness is the one you got from me, it's from a '92 Loyale GL Wagon PB4WD/5-speed.

I don't see Subaru making any harness changes with the Loyale line on it's way out of production, but it is possible.

 

Did you do anything with the plugs of the harness to the 4 relays under the dash?

There's Left & Right headlight relays, Fuel pump relay, Ignition relay. Would be easy to mix up one of those plugs. One of the headlight relays controls power for dash/running lights, but I don't recall which.

 

I don't have much for wiring diagrams, just the Haynes Manual.

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Okay. Was just wondering if you had made any changes to the cars wiring during the prior EJ swap that may still be there is all.

 

Do know that the '92 Wagon was a DD until the rear crossmember collapsed.

I bought it for parts, drove it on/off the trailer, and around the property until the time came that it was stripped for it's goodies.

 

Really unsure as to what would cause the issue at hand.

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Fairly certain that the fuel pump relay is controlled by the ECU in all the FI models.

 

Not sure on pin-out differences of ECU between auto seat belt standard seat belt ones.

Also not sure of pin-out difference between the rear main body harnesses either.

There's a few more wires for the auto belt stuff, but are the lighting, fuel pump, and other basic wires in the same position on both harnesses. I don't know...

All I have for wiring diagram info is a Haynes Manual with their "Typical" wiring info.

 

Only advice I can offer is to check pin-outs of the connectors for ECU and rear harness between the old and new harnesses. A pain in the arse job for sure.

 

I can send you the rest of the '92's wiring harness and ECU, just pay shipping cost.

I have no need for it, just kept it when I scrapped the Wagon.

Swapping the harness out is another PITA job though.

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Going to sell it as is... Its runs fine just have to know the trick. I will let the new owner know what the issue is and tell him he should just rewire the fuel pump, he likely won't have to run new lines just fix the one from the ecu to fuel pump.

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Well, it gives the car a some what built-in theft deterrent system. Might even be a good selling point as long as the rest of the electrical system works correctly.

 

I know around here, not many drivers of older vehicles will turn on the headlights during the day, even in poor visibility conditions.

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