1991 Chevrolet Lumina obd port.

1991 CHEVROLET LUMINA
161,000 MILES • 3.1L • 6 CYL • FWD • AUTOMATIC
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MIKE LUCKEY
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why do the cooling fans come on when I paper clip jumper A and B to read my obd1 engine codes? thank you in advance.
Mar 4, 2015 at 8:30 AM
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HMAC300
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it's been so long since I checked one I think it is designed to do that.
Mar 4, 2015 at 9:29 AM
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MIKE LUCKEY
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I thought that was probably the case. Having a bit of trouble with the fan not coming on. A/C doesn't work, so the secondary fan probably won't, but the primary fan should. I replaced the ECT and the relay. I took the connector wire off of the ect and jumperwired it and thought that would work, no dice. So I jumper wired in the relay socket from the always hot pin to the load (fan) pin and the fan came on! Could I have a problem between the ect and the relay??
Mar 4, 2015 at 2:15 PM
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HMAC300
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it may be a problem with the fuse box. check relay to see if you get any power to it if you do twist or bend the prongs a tad and see if it works that way. it may be making poor contactor corrosion. I can't get into a manual to check circuit out so thatis all I can advise now.
Mar 4, 2015 at 3:19 PM
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MIKE LUCKEY
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Will do. Is there only one pin (#30) that has power all the time in the relay plug? thank you again by the way!
Mar 4, 2015 at 9:52 PM
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HMAC300
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when you key up onewill come from ect/pcm and the other will go out to fan. one is ground.
Mar 5, 2015 at 5:37 AM
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MIKE LUCKEY
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thank you!
Mar 5, 2015 at 6:35 AM