Replacing alternator in 1970 Catalina wagon /w 400 motor

Harmiii

New member
9
0
1
I'll admit I am not the greatest mechanic around but I thought this should be a breeze. The bottom bolt of the alternator is behind the pulley for the power steering. I loosened the adjustment bolt on the back of the power steering pump thinking I could slid it out of the way but the way it is bolted on front I don't see anyway to move it. Any help would be greatly appreciated. Thank you in advance.
 

melsg5

Staff member
SUSTAINING MEMBER
22,246
284
83
I have replaced alternators on a 68 400 and 71 455. I have also looked in the 70 factory Service Manual. Never had to touch power steering bracket other than belt loosening.
Second picture in link bolt is behind belt. There is more than one bolt to move the PS pump.

 
Last edited:
Disconnect the battery.

Loosen the 2 bolts on the front of the power steering pump bracket, and a bolt in the back of the power steering bracket to the head. The top bolt in the power steering pump bracket goes to the head and is the bottom bolt for the alternator. The next one below that and the one in the head behind the power steering pump are the two bolts you use to adjust the tension on the power steering pump belt. When they are all loose, you can move take tension off the power steering pump and remove the power steering pump belt. Then you remove the bottom and top bolt for the alternator. There is also a spacer bushing that you need to save to reuse when to put in the new alternator. Good luck.
 

Harmiii

New member
9
0
1
Well I did what Kraig 1957 suggested. Actually I figured it out with fresher eyes after asking the initial question. I had to remove all bolts to the power steering pump and pull the pump towards the radiator until I could get the alt bolt out. Everything went together smoothly. I am concerned with Kraigs comment of a spacer bushing to reuse in the new alternator. I'm not sure I saw one before I disassembled but I'm not sure which bolt it should be on. Any suggestions, Kraig?
______________________________
 

Harmiii

New member
9
0
1
Thank you Kraig. My bracket is different. on Mine, the spacer must be built right into the bracket because my alternator dropped right in with a tight fit. I appreciate your help more than you know. Hopefully this fixwill keep my battery from discharging!

Harm
 

Harmiii

New member
9
0
1
No. The old alternator would charge. I think it has a bad diode letting juice go through constantly, running the battery down in about 24 hours. I wasn't sure that that could be checked.
______________________________
 

melsg5

Staff member
SUSTAINING MEMBER
22,246
284
83
I believe you set your voltmeter to AC, engine running, if you get a reading, bad diode.
Did you use an ammeter to check for a parasitic drain?
Did you have the battery load tested?
 

Harmiii

New member
9
0
1
I didn't try any of those because I didn't know any of those tests. I will try them. What I know is the voltage regulator is brand new. If I disconnect either the voltage regulator or the main wire to the alternator my battery stays up.
 

Harmiii

New member
9
0
1
So I finished installing the alternator. I had a slight spark when I hooked up the battery. Now the voltage regulator gets warm so I assume I still have a drain going. Anyone know anyplace to start? I am considering pulling fuses one at a time and checking for the spark at the battery.
 

melsg5

Staff member
SUSTAINING MEMBER
22,246
284
83
Look for a video on how to test GM external regulators. If you intend to keep the car buy the 1970 factory Service Manual.
______________________________
 
Top