Alternator question?
Team Owner
Joined: Jul 2006
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From: Kannapolis NC
It depends on the state of charge of the battery and the integrity of the connections, but normally between 13 to 14 volts. With a charged battery, mine reads around 13.7 on a long drive. It will read a little higher just after a start or if your battery is down a little.
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From: Lake Havasu City, AZ
PM EvilTwin he is a retired GM engineer and the Forum expert on C5alternators ( among other things)
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
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Racer
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From: CA
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Well its for a 12 VDC system. That doesnt mean that it wont output the correct voltage and current. Install it and see what the output voltage is.
Make SURE that you read the output directly on tha battery terminals.
As long as its the same style alternator as the old one, you will be fine..
Why are you replacing the alternator??
BC
Make SURE that you read the output directly on tha battery terminals.
As long as its the same style alternator as the old one, you will be fine..
Why are you replacing the alternator??
BC
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Racer
Joined: Aug 2007
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From: CA
Battery kept going down and keep getting charging sys fault. Had AZ ck it and it showed
it was bad. Also put in new battery. Still get charging sys fault. Had ECM checked and it
showed it is bad. No voltage to alt. I just want to be sure the new alt will not screw up the new ECM. glassman
it was bad. Also put in new battery. Still get charging sys fault. Had ECM checked and it
showed it is bad. No voltage to alt. I just want to be sure the new alt will not screw up the new ECM. glassman
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
The large RED wire on the back of the alternator is the BATT wire. It connects to the battery thru the starter solenoid.
Seen TOO MANY alternators get changed when the only issue was a POOR solenoid connection or damaged solenoid connection.
Just want to make sure that your not replacing something that does not need to be changed. Do you read battery voltage on tha BATT connection when the engine is OFF?????
If not,,, the problem lies somewhere else.
BC
BC
Seen TOO MANY alternators get changed when the only issue was a POOR solenoid connection or damaged solenoid connection.
Just want to make sure that your not replacing something that does not need to be changed. Do you read battery voltage on tha BATT connection when the engine is OFF?????
If not,,, the problem lies somewhere else.
BC
BC
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Racer
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From: CA
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
NO IT IS NOT! You can run it as long as the battery is charged. Without the alternator RECHARGING IT, you will soon run out of battery and the car will DIE!
If you mean to use a jumper wire,,, the answer is still NO. It’s a good test but NOT a solution!!
Something caused the wire to SHORT and blow that FUSE LINK!!
You may have a MAJOR ISSUE (read; SMOKE, FIRE, FLAMES) IF, you use a NON FUSED jumper wire to jump the BATT terminal to the battery, and you run the risk of catastrophe.
If it were me,, I would jack the car up and carefully examine that wires on the starter and the wires in the harness going to the starter. They frequently get toasted and short out.
That’s your best approach. You know that you have an issue because the wire is OPEN. The fused links are right there at the solenoid area. Look for a bump in the wire. The wire will change colors from red to some other color. There’s usually a brown sealer that leaks out of the joint when the factory manufactures the fuse link.
BC
If you mean to use a jumper wire,,, the answer is still NO. It’s a good test but NOT a solution!!
Something caused the wire to SHORT and blow that FUSE LINK!!
You may have a MAJOR ISSUE (read; SMOKE, FIRE, FLAMES) IF, you use a NON FUSED jumper wire to jump the BATT terminal to the battery, and you run the risk of catastrophe.
If it were me,, I would jack the car up and carefully examine that wires on the starter and the wires in the harness going to the starter. They frequently get toasted and short out.
That’s your best approach. You know that you have an issue because the wire is OPEN. The fused links are right there at the solenoid area. Look for a bump in the wire. The wire will change colors from red to some other color. There’s usually a brown sealer that leaks out of the joint when the factory manufactures the fuse link.
BC
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If you carefully examine the picture in this post,, look at the TAN wire on the solenoid. It goes to a BLACK heat shrink and that goes to a RED wire. Thats the FUSE link that is most likely blown.
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
If a wire that is connected directly to the BATTERY (650 AMPS) accidently gets shorted to ground,, that wire will become SMOKE FIRE AND FLAMES VERY QUICKLY!!!!!
BC
BC
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Examine this schematic:
\See if you can find the FUSE/s??????????
Circuit Protection - Fusible Links
Fusible link is wire designed to melt and break continuity when excessive current is applied. It is often located between or near the battery and starter or electrical center. Use a continuity tester or a DMM at each end of the wire containing the fusible link in order to determine if it is broken. If broken, it must be replaced with fusible link of the same gage size.
Repairing a Fusible Link
Important
Fusible links cut longer than 225 mm (approximately 9 in) will not provide sufficient overload protection.
Refer to Splicing Copper Wire Using Splice Clips .
I can NOT find the fuse size info in the servicemanuals YET.
Still looking.
Maybe the dealer sells the replacement inline fuse links. If its blown, I would see if the dealer has the replacement fuse links.
BC
\See if you can find the FUSE/s??????????
Circuit Protection - Fusible Links
Fusible link is wire designed to melt and break continuity when excessive current is applied. It is often located between or near the battery and starter or electrical center. Use a continuity tester or a DMM at each end of the wire containing the fusible link in order to determine if it is broken. If broken, it must be replaced with fusible link of the same gage size.
Repairing a Fusible Link
Important
Fusible links cut longer than 225 mm (approximately 9 in) will not provide sufficient overload protection.
Refer to Splicing Copper Wire Using Splice Clips .
I can NOT find the fuse size info in the servicemanuals YET.
Still looking.
Maybe the dealer sells the replacement inline fuse links. If its blown, I would see if the dealer has the replacement fuse links.
BC