Mechman Alt 250A 4.3 S-10/S10 Blazer/Jimmy

Blazin_Jason
10+ year member

CarAudio.com Elite
Well I'm almost finally done installing my new alt. USPS/Canada Post decided to make me wait months after it was dropped and broken in shipping. Long story short international insurance FTL, Mechmans FTW. Last week I received a non broken alt and went to install it. It didn't quite just bolt in like I thought it might. Understanding that the new alt is physically larger and might take some mods I had to make it work. (strapped saz1500ds @ 1 each, 100.2, couple 1/0 runs, 2 red top 34's)

Stock alt charging voltage at idle with no real load.

alt7.jpg


Played a test tone and voltage at idle dropped down.

alt15.jpg


Old alt vs. new alt. CS130 old, CS144 mechman.

alt5.jpg


alt6.jpg


This little area on the new alt was hitting the old rear support bracket. I didn't really want to cut the old bracket off in case I ever need to go back to stock alt. Removing the bracket can't be done without removing the PS pump. What I did was grind it off instead. Not recommended and would be better removed before the alt is assembled.

alt4.jpg


alt3.jpg


Now that it sorta fits I was only able to get 1 bolt in out of the 2. As you can see below the holes don't quite line up. Mechman said that normally that there is enough wiggle room to get the bolt in. I tried but it just wasn't gonna happen. So I opened up the hole a little so the bolt would fit.

alt1.jpg


Grinded open just enough via dremel and 2 minutes of time.

alt14.jpg


The ear on the new alt is longer so you need a new bolt. I also made a brass sleeve to take out any extra slop/slack between the case and bolt. Used an M8x70mm bolt, washers and nut. The old bolt threaded into the old alt case.

alt12.jpg


Now it's in and bolted in nice and tight. Here you can see the rear bracket which I chose to leave and just bent it back slightly. Obviously not enough as it still touches the case. I'm just leaving it for now. Had I not grinded the case there is no way it would fit here. You would definitely need to remove the old bracket.

alt13.jpg


 
Here it is. I needed to also lengthen 2 fusible links that connected to my alt. The wire was about 2 inches too short so I just added some 12g wire to make it reach.

alt11.jpg


Nice things with their alts are the ground post stud directly on the alt.

alt10.jpg


alt9.jpg


Here is output at idle with no load. I didn't want to play the same tone right now to see what it drops down to. I did go for a little drive and I can definitely notice the voltage is up and holds WAY better than stock. Even at a stop full tilt I was happy. I just need to get the voltage reading under full load.

alt8.jpg


I went to put everything back together on the truck but now the air cleaner doesn't fit, hah. Guess where the housing wants to hit? Yup right on the output stud. So for right now I had to change the intake to make it kinda work. I always meant to build a cai for this thing but just never got around to it. Now I NEED to order the parts and make it. I've only had the alt in for a few hours but I am glad I went with mechman. They have been very helpful through my whole ordeal. Will update as time goes. Thanks again Mechman for everything!

 
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Blazin_Jason

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