Zfighter76 Posted October 27, 2014 Report Share Posted October 27, 2014 so I recently bought a 1978 b210, seller said just needs alternator. I replaced the alternator because I was stupid and believed him, and same problem, reads 12 volts when running with lights off, and it shuts off when I unplug the battery. the charge light works so that's not it, all fuses and connections are good, continuity to all wires. the thing I am most uncertain of is the alternator itself. it looks very similar to the hitachi unit that was on the car but one thing that I read is that 78+ b210s had internally regulated alternators. this makes sense because I found no voltage regulator or open connections for one anywhere. I just don't know if it had the wrong alternator in it when I bought it too, looks old but who knows how long it was not charging for. also the production date reads 77' but its registered as a 78'. any help? all wiring is original but good, checked continuity of all the wires ("bat" to battery, "e" to earth), and the battery is also new. wasn't sure how to test the "t" plug on the alternator though. thanks! Quote Link to comment
datzenmike Posted October 27, 2014 Report Share Posted October 27, 2014 The build dates for the '78 model year starts in August '77 I believe. Look on the door jam tag or consult the emission sticker on the under side of the hood. If a '78 you will need an internally regulated alternator. That said.... Look on or very near the positive battery post for the fusible links. They are about 4" long with plastic connectors at each end so they can be removed and replaced. There are maybe 3 or 4 of them likely Green and /or Black possibly a Red one too. They are designed to melt like a fuse but resist catching fire. One may appear melted or burnt and crispy. Check them for continuity with a test lamp. Quote Link to comment
spottedog Posted October 27, 2014 Report Share Posted October 27, 2014 If you have the Hitachi alternator, it is common for it to be so old the brushes are worn out. his happened to my B210, I ordered a brush kit from Rock Auto, easy to take apart and put the new brushes in, works great. If you do this, also order starter brushes, both sets are like $4.00 to $6.00 each set. 1 Quote Link to comment
banzai510(hainz) Posted October 27, 2014 Report Share Posted October 27, 2014 spotteddog he replaced the alt. so why buy brushes and he tearing apart a alt? have alt tested at Napa or where ever. If good then ck for conncttion to the T plug and make sure one of the leads gets 12volts to energize the alternator. Or the fuse box to ck the alternaotr. If alt is not energized it wont charge. Had this happen with my 521. I found out my fdash elelctrical plug was loose and the 12volt never went to the alternator. Why it routed the 12volt to the dash I forgot( I think dash light as it didnt work and popped the fuse) Quote Link to comment
Zfighter76 Posted October 27, 2014 Author Report Share Posted October 27, 2014 thanks guys, I believe the problem is that I have an externally regulated alternator on a car that should have an internally regulated one then. i tested continuity through the fusible links and they are fine. the door jamb does say 77' but again there is no external regulator to speak of and no connector for one. i will return to oreillys and return the external reg alt and head over to napa since it seems like they know what theyre doing a bit better. hopefully they can get me the correct alternator. ill post my findings after, thanks again! Quote Link to comment
Zfighter76 Posted October 27, 2014 Author Report Share Posted October 27, 2014 oh yeah and my door jamb reads 9/77 so its a 78 model year. off to get a new alt now. Quote Link to comment
Zfighter76 Posted October 28, 2014 Author Report Share Posted October 28, 2014 good news! went back to oreillys and returned the alternator i just bough, turns out they had a remanufactured hitachi ir alternator in stock, so i swapped and it charges perfectly now, though i did have to go back again to get a different belt to fit. took her for a spin around the building at my work and she drives like a dream. before it idled a bit high and felt like it had a vaccum leak, i believe because the alternator was just free spinning, now that it has some load it runs completely different. thanks for the help guys! Quote Link to comment
datzenmike Posted October 28, 2014 Report Share Posted October 28, 2014 Probably the auto choke relay wasn't working and the fast idle was on. Good to hear you got it. Quote Link to comment
Zfighter76 Posted October 29, 2014 Author Report Share Posted October 29, 2014 would the alternator not working turn the fast idle on? and thanks again ratsun is always very helpful. Quote Link to comment
datzenmike Posted October 29, 2014 Report Share Posted October 29, 2014 Usually the auto choke relay requires alternator output in order to be on. Without the auto choke relay on there is no power to the choke heater and the choke can't warm up properly and stays partly on. If the choke is on usually the fast idle cam is engaged too. You may notice a healthy increase in mileage now as the choke will be shutting off. Quote Link to comment
Zfighter76 Posted October 30, 2014 Author Report Share Posted October 30, 2014 cool that's great info. I have yet to drive the car more than around the parking lot once or twice at my work because the car was in an accident and has no radiator or lights. im getting to fixing that now that its running good. ill start a build thread , ive been taking a ton of oics on this one haha Quote Link to comment
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.