Need help keep blowing fuses - The 1947 - Present Chevrolet & GMC Truck Message Board Network

champions53 · 02-07-2011, 02:03 AM

Ok prob just a rookie moment for me but, inline fusable link one going into cab near firewall driverside blew on my 81 then alt overcharged and blew ignition module. So I replaced fusable link with inline fuse and new module also new altenator. Everything seemed fine but started blowing the fuse now at anything above idle. Im lost please help.

gchemist · 02-07-2011, 05:28 AM

Check your grounds. You have a bad ground somewhere. Ground the engine properly to the frame.

BigBlocksRule · 02-07-2011, 07:57 AM

edited

champions53 · 02-07-2011, 11:44 AM

Checked grounds and cleaned look good. Still blows fuse though. I hate electrical issues my weak point and it sucks.

panhandler62 · 02-07-2011, 01:23 PM

Bad grounds don't tend to blow fuses. Fuses melt from excess current. Grounds are so frequently the malady in these old trucks that we sometimes leap to quickly to that conclusion.

I'm not real familiar with the wiring in an 81 but it sounds like a regulator issue to me.

fixit-p · 02-07-2011, 01:59 PM

Sounds like you have a bad short somewhere. What type of fuse and what amperage are you using?

Longhorn Man · 02-07-2011, 07:19 PM

are you still overcharging?

CaptRMW · 02-07-2011, 08:05 PM

Quote:

Originally Posted by champions53

Ok prob just a rookie moment for me but, inline fusable link one going into cab near firewall driverside blew on my 81 then alt overcharged and blew ignition module. So I replaced fusable link with inline fuse and new module also new altenator. Everything seemed fine but started blowing the fuse now at anything above idle. Im lost please help.

Check the red wire in the flat plug that is plugged into the alternator (make sure it is red and not brown), it should read battery voltage to tell the alternator when and how much to charge. It is a good bet that this wire has lost connection to the battery and the alternator is going full charge. If you have only toasted the module consider yourself lucky as I have seen 18 plus volts and complete digital dash panels gone to toast with this problem. Good luck, Roger

champions53 · 02-08-2011, 12:50 AM

Thanks guys for the help! When a get another day off Im going back at it again to check the stuff you have pointed out. Ill update this weekend.

02-07-2011, 02:03 AM	#1
champions53 Registered User Join Date: Jun 2010 Location: Owensboro, Ky Posts: 51	Need help keep blowing fuses Ok prob just a rookie moment for me but, inline fusable link one going into cab near firewall driverside blew on my 81 then alt overcharged and blew ignition module. So I replaced fusable link with inline fuse and new module also new altenator. Everything seemed fine but started blowing the fuse now at anything above idle. Im lost please help.

02-07-2011, 05:28 AM	#2
gchemist BAD BOW-Silverado XST Join Date: May 2000 Location: Senior Member from Austin, TX Posts: 6,431	Re: Need help keep blowing fuses Check your grounds. You have a bad ground somewhere. Ground the engine properly to the frame. __________________ Gerardo a.k.a. Mad Chemist Silverado XST videos

02-07-2011, 07:57 AM	#3
BigBlocksRule Registered User Join Date: Jun 2008 Location: Lubbock, TX Posts: 2,047	Re: Need help keep blowing fuses edited Last edited by truckdude239; 02-07-2011 at 08:19 AM. Reason: not needed

02-07-2011, 11:44 AM	#4
champions53 Registered User Join Date: Jun 2010 Location: Owensboro, Ky Posts: 51	Re: Need help keep blowing fuses Checked grounds and cleaned look good. Still blows fuse though. I hate electrical issues my weak point and it sucks.

02-07-2011, 01:23 PM	#5
panhandler62 Java Mechanic Join Date: Jun 2005 Location: Martinsburg, WV Posts: 6,763	Re: Need help keep blowing fuses Bad grounds don't tend to blow fuses. Fuses melt from excess current. Grounds are so frequently the malady in these old trucks that we sometimes leap to quickly to that conclusion. I'm not real familiar with the wiring in an 81 but it sounds like a regulator issue to me. __________________ Keith 11 Lincoln MKT -- Momma's wagon 13 G37xS -- middle age crazy car 68 C20 Fleetside -- RIP Decorating the whole town up at a cost of $27 ....

02-07-2011, 07:19 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Need help keep blowing fuses are you still overcharging?

02-08-2011, 12:50 AM	#9
champions53 Registered User Join Date: Jun 2010 Location: Owensboro, Ky Posts: 51	Re: Need help keep blowing fuses Thanks guys for the help! When a get another day off Im going back at it again to check the stuff you have pointed out. Ill update this weekend.

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