Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
10-10-2020, 09:43 PM | #1 |
Registered User
Join Date: Aug 2020
Location: Florida
Posts: 8
|
Stock 250 CID / I6 Alternator wiring picture
I can’t get my ‘72 Blazer started (250 CID I6) after removing the alternator (rookie mistake of assuming I’d remember the wiring / not photographing the wiring prior to taking it apart). So, can anyone please send me a picture of the alternator wiring in your stock I6 250 CID engine. Many thanks in advance.
Posted via Mobile Device |
10-10-2020, 10:19 PM | #2 |
Senior Member
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
|
Re: Stock 250 CID / I6 Alternator wiring picture
There are only 3 connections. The Red lead goes on the positive terminal. This is the biggest one and is more outboard. Some alternators have a stud connection that's red inside, under a rubber ''hood.'' The field connector is a dual-lead plug that snaps in to the socket at 12'o'clock on the back of the case. The Ground stud is more inboard and connected by a smaller Black lead, sometimes there's a metal clamp crimped around the whole bundle with a tab that goes into a slot on the back of the Delcotron casing. It's secured by a smaller nut.
__________________
Every 25 years I like to rebuild that 292, whether it needs it or not. |
10-11-2020, 08:30 PM | #3 |
Registered User
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,716
|
Re: Stock 250 CID / I6 Alternator wiring picture
I'll get one of my 68 in the morning
__________________
Mark 72 c20 custom camper Husky edition, 66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark 1969 AMX , 1968 c20 stepside ,85 K20 1977 Suburban sold 68 anniversary. |
10-11-2020, 08:46 PM | #4 |
Registered User
Join Date: Aug 2020
Location: Florida
Posts: 8
|
Re: Stock 250 CID / I6 Alternator wiring picture
Thanks Mark. I’m pretty sure I have the wiring correct but it still won’t start. It turns over but doesn’t engage.
|
10-11-2020, 09:01 PM | #5 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,842
|
Re: Stock 250 CID / I6 Alternator wiring picture
Under normal circumstances, the simple act of replacing the alternator shouldn't cause a no start condition.. i suspect you have another problem.. Engine cranking over but not starting is not a symptom of a failed alternator.. Why was the alternator replaced??
|
10-11-2020, 09:38 PM | #6 |
Registered User
Join Date: Aug 2020
Location: Florida
Posts: 8
|
Re: Stock 250 CID / I6 Alternator wiring picture
You’re right RustyPile. The alternator was not technically replaced. I changed the belt and removed the alternator due to stripping the threads in the top / bracket position, only to find out from someone much smarter on this very forum, that all I had to do was replace the screw with a longer version and tighten it with a bolt. But by then I had already removed the wire connections to the alternator... All this to say that I’m confident it’s not the alternator. I’ve got a couple of ideas to try out based on what I did. So I appreciate your help and those who are following this thread. I’ll keep you posted with the outcome, but not till later in the week, when I can get back to the Blazer.
|
10-11-2020, 11:27 PM | #7 |
Senior Member
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
|
Re: Stock 250 CID / I6 Alternator wiring picture
Probably the Solenoid. Redundant ground straps never hurt either. Battery connections...
__________________
Every 25 years I like to rebuild that 292, whether it needs it or not. |
10-12-2020, 12:35 PM | #8 |
Registered User
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,716
|
Re: Stock 250 CID / I6 Alternator wiring picture
Really not much to wire up .
__________________
Mark 72 c20 custom camper Husky edition, 66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark 1969 AMX , 1968 c20 stepside ,85 K20 1977 Suburban sold 68 anniversary. |
10-12-2020, 01:22 PM | #9 |
Registered User
Join Date: Aug 2020
Location: Florida
Posts: 8
|
Re: Stock 250 CID / I6 Alternator wiring picture
Thank you Mark. This is visual confirmation that I got it right. What threw me off was the bracket that ties-in the the bolt which appears to do nothing other than keep the wires tidy.
|
10-12-2020, 04:47 PM | #10 |
Senior Member
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
|
Re: Stock 250 CID / I6 Alternator wiring picture
When you mount it on the Negative stud, and top it with the black ring terminal, and slip the tab into the slot, it grounds the casing to the Ground circuit.
__________________
Every 25 years I like to rebuild that 292, whether it needs it or not. |
10-12-2020, 04:52 PM | #11 | |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,842
|
Re: Stock 250 CID / I6 Alternator wiring picture
Quote:
|
|
10-12-2020, 05:00 PM | #12 |
Registered User
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,716
|
Re: Stock 250 CID / I6 Alternator wiring picture
The black wire goes under the tab to make contact with the alternator.
__________________
Mark 72 c20 custom camper Husky edition, 66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark 1969 AMX , 1968 c20 stepside ,85 K20 1977 Suburban sold 68 anniversary. |
10-12-2020, 05:08 PM | #13 |
Senior Member
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
|
Re: Stock 250 CID / I6 Alternator wiring picture
I put the tab on the bracket into the slot on the back case of the Delcotron, with the hole over the stud, then mount the Black lead ring terminal on the neg. stud over it and secure with the nut. The bracket is a combination ground connection and harness protector. Fit is better in this sequence.
__________________
Every 25 years I like to rebuild that 292, whether it needs it or not. |
10-12-2020, 05:26 PM | #14 | |
Registered User
Join Date: Jul 2018
Location: Catskill Mountains,NY
Posts: 8,716
|
Re: Stock 250 CID / I6 Alternator wiring picture
Quote:
__________________
Mark 72 c20 custom camper Husky edition, 66 SS396 Chevelle 1964 Hawk, 63 Avanti,62 lark 1969 AMX , 1968 c20 stepside ,85 K20 1977 Suburban sold 68 anniversary. |
|
10-12-2020, 11:06 PM | #15 |
Senior Member
Join Date: Feb 2002
Location: Tucson, AZ USA
Posts: 7,504
|
Re: Stock 250 CID / I6 Alternator wiring picture
Here in AZ, I don't have the corrosion problem. I file the bracket/keeper/tab clean with a ingnition file. But on my latest alternator, these's a flanged 3/8'' bolt threaded into the case back. I have a ground strap bolted there connecting with a motor mount bolt, that also has a bigger ground strap to the frame. Can't have too many ground straps.
__________________
Every 25 years I like to rebuild that 292, whether it needs it or not. |
Bookmarks |
Thread Tools | |
Display Modes | |
|
|