Alternator/voltage regulator issue?

JNewm

JNewm

True Classic
Hi all--

Ran into some fun electrical issues today. Voltage gauge was reading sub-12 and going lower while driving, which seemed like an obvious alternator issue. But the idiot light underneath the gauge would also start to glow as revs increased, leading me to suspect voltage-regulator issues. Took the car to O'Reilly, their test came up "voltage regulator failure".

I haven't gotten the chance to get under the car and remove the alternator yet, but it's a 1981 non-AC car. From what I can gather online, that means it most likely has a 55-amp alternator with either an internal or (attached) external voltage regulator.

I see Midwest-Bayless sells a "self-regulated" (internal) 55-amp alternator here.

First question: can I replace my existing alternator + voltage regulator with this unit, even if what's currently on the car is an external regulator? I can't think of a reason why not, but electrical systems have never been my forte.

Second question: I see Vick sells a 65-amp alternator here. Does anyone have experience installing one of these? Would you need to also upgrade wiring to notice any difference, or can the stock wiring handle the extra power?

Thanks in advance!
 
Welcome to Xweb JNewm! You dont really need to get under the car. Your 81 has a large access panel in the rear trunk that gives good access the the alternator. You might be able to replace the regulator with out removing the alt, but I am not 100% sure on that. The "internal" regulator is actually bolted to the back side away from the pulley.

Did you check the belt tensioner and condition?

You can use the 55 or 65amp alt, the wiring can handle it. (Update: see my note below. The Vicks 65 amp looks to be for an AC X)
 
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One other note. On that Vick's 65 amp, the mounting tabs looked odd to me. In the description it says:

"Remanufactured alternator X 19 and Strada (with AC 65 AMP) 1980-88. (90 Day Warranty)."

So that is an alt for an AC equipped X.

Here is the access panel opening on my 86, you can see the alternator on the right.
IM002515.JPG
 
As Jim said, you should be able to replace the voltage regulator without removing the alternator. But either way, if the alternator itself is good then no need to replace both, just the reg. This is true for either type of regulator - internal or external. A regulator is much less expensive than the full alternator.

And yes, the AC equipped cars had a slightly larger alternator output (depending on the year) but they are completely different mounting. So not interchangeable.

If you decide you want to replace the alternator anyway, consider having it rebuilt at a local alternator specialist shop. Not only is it likely to be of better quality and less expensive than buying a new one, but they can also increase the amperage output (if that is what you want).
 
This is all super helpful; thank you both! (And thanks for the welcome!)

Heading out to the garage now. The belt visually looked okay. I'll check the tension--does ~1/2" of play sound about right?

We used to have a great local shop, but they've been closed for going on a decade now. Seems like fewer and fewer of those types of businesses remain open with each passing year.
 
When you look at it, you can tell which type it is from the rear.

The Bosch alternator has what they call a "internal" regulator, but to me it is so easy to replace I'd call it external. Looks like this:
10808227_wpc_f4010425065bos_pri_larg.jpg

I drew the red line to show what you will see externally (below the line). The part above the line goes inside the alternator and has the brushes (two posts sticking up). So you get a new voltage reg and brushes for about $10. Two bolts hold it to the back of the alternator, no wires.

The Magnetti Moreli regulator looks like this:
s-l400.jpg

You will see it bolted to the back of the alternator case.

Either are easy to replace.
And welcome. Sorry I did not notice that you just joined. Have you had the X long? And is it your first?
 
Welcome.

If.....you have an '81 X1/9 non A/C.....and if it is a North American spec car (it would then be fuel injected).....it would have come from the factory with a Bosch 65amp alternator. The type with a built-in (well actually bolted-on) regulator/brush unit (like Dr Jeff shows).

By the way....A/C X1/9s in your year would have come with a Bosch 70amp unit...that is NOT interchangeable with yours as the mountings are all different.

Other years - and elsewhere in the world - came with either a Bosch or Marelli alternator - sometimes with the regulator in the alternator - and sometimes with an external one.

Watch out....as it is possible that a previous owner of your X1/9 had retrofitted/adapted a GM or Nissan alternator to fit on there. Many folks here have done just that.

But if...your X still has the original type alternator ( it will say Bosch on it in a couple of places ) then yes you can change the brush/regulator part of it quite easily. That part should be easy to get from our Fiat suppliers...or easily elsewhere ( like your local O-Reilly's ) as it was common to other euro cars - like VWs- of the era.

Hope this helps.
 
Wow, thanks all for all the tips!! Got the access compartment lid off (and found a new patch of rust on the bottom lip of it), the cooling duct removed, and the rear shield removed. It is indeed the Bosch 65-amp alternator. And it has the Bosch regulator just like Dr. Jeff shows.

Another question (there's always another; isn't there?): the long bolt that runs through the far side of the alternator (closer to the engine block) can't be tapped out all the way. The head of it runs into the plastic fender liner. I removed the adjuster bolt and the bracket that holds it, but can't wiggle the alternator enough to get that long bolt out.

Question #3: Do you need to remove the plastic fender liner to slide that long bolt out? Or is there some trick I'm missing?

I was actually thinking of starting a thread on the X at some point, but here's the short version of the story. It was my very first car, bought back in 2001 when I was in high school. It was a literal barn find--it had been sitting for quite awhile in an elderly woman's barn, where its owner had parked it. My dad and I did a light restoration back then, and painted it. I drove it for awhile, including as a daily driver for some periods, but mothballed it in about 2011. It then sat in a (different) barn for ~5 years while my wife and I moved around the country. We're back home as CoVID refugees, and I finally had the time and the opportunity to pull it out of storage and coax it back to life. It's been super fun--honestly, to the point of mild obsession.

The downside is that the rust is back with a vengeance, to the point that it will need a serious frame-off resto at some point in the not-too-distant future. (Like, baseball-sized holes in the rocker panels rust.) Trying to figure out what to do long-term, but again, just having a ton of fun in the short term.
 
Only the front has a full fender liner. On the rear there is a little splash shield held on by a couple of screws. Been a while - but I guess you will have to remove that shield to be able to slide that long bolt out....

As others have said...you should be able to unbolt the regulator/brush assembly with the alternator still in place. By the way....disconnect the battery first as there are always-live non-fused wires there !!

If....the car has been sitting for 10 years....it is possible that the problem is just that the brushes are just kinda seized in their holders. They are spring loaded Look at Dr. Jeff's pic and you can sorta see how they work. Perhaps they are just a bit stuck. Nothing to lose by seeing if they move freely - and just work them back and forth a bit if they are. Or you should be able to get a new regulator.brush unit pretty cheap.

Good story. And yeah....you will always find new rust......

Edit....now I am NOT saying for sure that fixing/replacing your regulator/brush assembly will cure your problem. Still could be a wiring issue or another internal problem in the alternator itself. Just a likely cure.......
 
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If you decide to remove the long pivot bolt, when reinstalling, orient it so the threads are outboard and the bolt head is inboard, and the nut is in the spot on the alt's outboard mounting ear that looks like it was made to capture the nut.

If you replace the brush and regulator assy with the alt in-place, you may find that a skinny line-up tool inserted into one of the two mounting screw holes will help you keep the assy in place so that you can run the first mounting screw in. Otherwise you will be fighting the spring-loading of the brushes while simultaneously trying to get the first mounting screw started.

Fitting and adjusting the alternator-crank-water pump belt is nowhere near the root-canal-like ordeal of doing the belts on an A/C car, but there is a trick (or two). The geometry of the adjustment pivot path of the alternator results in a very small swing of belt adjustment as you swing thru the adjustment path. Sometimes you end up in a situation where at max adjustment the belt is still too loose but perversely at maximum slack the belt is still too tight to get off the pulleys! The solution I've used is to get a belt (Dayco 15325) that is sized so that it's properly tensioned a little past the halfway point of the adjustment arc of the alt---but this small of a belt makes it impossible to get the belt onto the three pulleys. The trick is to pull out the long lower pivot bolt allowing you to twist the alt so that you can angle the pulley so that its rear is far enough forward to slip the belt over it, then re-orient it back to its normal positioning, allowing the long pivot bolt to be reinstalled, and then the job completed.
 
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Quick update: the job is done, and the alternator is happily kicking out ~14 volts!

Since I was on a bit of a time crunch--planning to depart for a cross-country road/camping trip next week--I ended up ordering the universal-ish non-AC 55-amp alternator from Midwest, along with a new belt. Several hours later, the X is road-worthy again.

Just in case anyone stumbles across this asking similar questions in the future, here's a short rundown of the process, along with the one hiccup I encountered:

  1. Disattach engine blower unit in rear trunk, remove hose.
  2. Remove rear firewall carpet.
  3. Remove rubber trunk liner.
  4. Remove aluminum trunk tray and insulation.
  5. Remove rear engine access compartment panel (10 Phillips screws). Now you can get at the alternator.
  6. Remove alternator cooling duct/rear shield from alternator.
  7. Remove alternator adjustment bolt and mounting bracket.
  8. Remove wires attached to alternator.
  9. Remove plastic splash shield (held on by several 8-mm screws).
  10. Remove small metal tray that helps hold plastic splash shield up (more 8-mm screws).
  11. Now you can remove the nut on the long bolt and tap it out.
  12. Remove the alternator belt and alternator.
  13. Replace everything in reverse order!
I ended up putting the long bolt back in the same way (nut away from right rear fender, bolt seated in alternator hex seat). My thought process on this was two-fold, in case it needs removing again in the future. First, I'd rather wrench on a nut than a bolt. Second, it's trickier to tap the long bolt out if you seat the nut in the hex seat on the fender side. (That said, it can be done, as I tried it both ways.)

The one hiccup: the Midwest universal-ish alternator worked great, except that my stock rear shield (the thing that accepts the cooling duct hose from the right side vent) did not fit onto it. Like, not even close. I ended up getting one nut on it and wiring it into place, but there's a ~2-cm gap left. Still happy overall, as this was the only replacement unit available on short notice. VAS is out of stock on replacements. Per the Vick guy on the phone, X owners have not been returning cores, thinking that the original unit might be valuable for concours-type restos.

Thanks again for all the help!! I couldn't have done it without y'all. I'm new to Xweb, but am blown away by the friendliness and helpfulness on display. This is a wonderful corner of the Internet.
 
One more thing to emphasize: as @Dan Sarandrea (Phila) noted above, installing the belt is a small bit of fun. You'll want to get the belt on all the pulleys first, THEN mount the alternator. There's no way you'll be able to mount the alternator first, then stretch/roll the belt on.
 
JNewm said:
Quick update: the job is done, and the alternator is happily kicking out ~14 volts!

Since I was on a bit of a time crunch--planning to depart for a cross-country road/camping trip next week--I ended up ordering the universal-ish non-AC 55-amp alternator from Midwest, along with a new belt. Several hours later, the X is road-worthy again.

Just in case anyone stumbles across this asking similar questions in the future, here's a short rundown of the process, along with the one hiccup I encountered:

  1. Disattach engine blower unit in rear trunk, remove hose.
  2. Remove rear firewall carpet.
  3. Remove rubber trunk liner.
  4. Remove aluminum trunk tray and insulation.
  5. Remove rear engine access compartment panel (10 Phillips screws). Now you can get at the alternator.
  6. Remove alternator cooling duct/rear shield from alternator.
  7. Remove alternator adjustment bolt and mounting bracket.
  8. Remove wires attached to alternator.
  9. Remove plastic splash shield (held on by several 8-mm screws).
  10. Remove small metal tray that helps hold plastic splash shield up (more 8-mm screws).
  11. Now you can remove the nut on the long bolt and tap it out.
  12. Remove the alternator belt and alternator.
  13. Replace everything in reverse order!
I ended up putting the long bolt back in the same way (nut away from right rear fender, bolt seated in alternator hex seat). My thought process on this was two-fold, in case it needs removing again in the future. First, I'd rather wrench on a nut than a bolt. Second, it's trickier to tap the long bolt out if you seat the nut in the hex seat on the fender side. (That said, it can be done, as I tried it both ways.)

The one hiccup: the Midwest universal-ish alternator worked great, except that my stock rear shield (the thing that accepts the cooling duct hose from the right side vent) did not fit onto it. Like, not even close. I ended up getting one nut on it and wiring it into place, but there's a ~2-cm gap left. Still happy overall, as this was the only replacement unit available on short notice. VAS is out of stock on replacements. Per the Vick guy on the phone, X owners have not been returning cores, thinking that the original unit might be valuable for concours-type restos.

Thanks again for all the help!! I couldn't have done it without y'all. I'm new to Xweb, but am blown away by the friendliness and helpfulness on display. This is a wonderful corner of the Internet.
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Hi there. When you said “Midwest universal-ish alternator”, which one from their site did you purchase? And before replacing it, what kind of output voltage was the old one producing to get you concerned in the first place? I see you said “sub 12 on the gauge” - was that the dash gauge, or a multimeter?
thanks.
 
tvmaster said:
Hi there. When you said “Midwest universal-ish alternator”, which one from their site did you purchase? And before replacing it, what kind of output voltage was the old one producing to get you concerned in the first place? I see you said “sub 12 on the gauge” - was that the dash gauge, or a multimeter?
thanks.
Click to expand...

This is the one: https://www.midwest-bayless.com/Fia...aritmo-all-without-ac-self-regulated-new.aspx. I call it "universal-ish" because it didn't have a way to mount the zinc(?) shroud/seal thing that connects the cooling hose to the back of the alternator.

The old unit wasn't kicking out enough juice to keep the engine running; it was shot. (I think maybe only the voltage regulator was shot, actually, but I just replaced the whole thing.) The needle on the dash gauge stayed buried in the red even when the engine was being revved.
 
JNewm said:
This is the one: https://www.midwest-bayless.com/Fia...aritmo-all-without-ac-self-regulated-new.aspx. I call it "universal-ish" because it didn't have a way to mount the zinc(?) shroud/seal thing that connects the cooling hose to the back of the alternator.

The old unit wasn't kicking out enough juice to keep the engine running; it was shot. (I think maybe only the voltage regulator was shot, actually, but I just replaced the whole thing.) The needle on the dash gauge stayed buried in the red even when the engine was being revved.
Click to expand...
Is this the one MWB recommended?
 
tvmaster said:
Is this the one MWB recommended?
Click to expand...

I think it was the only one in stock that fit. For fitment purposes, I *think* all that matters is whether your car has AC or not--the mounting position was the same for all non-AC cars. I was a bit concerned that this was a 55-amp unit, replacing a 65-amp OEM unit, but the vendor explained that 55 amps should be more than enough to power everything. They were (unsurprisingly) correct. :)
 
AAA fellow came out today and said “you’re alternator’s not great, and it’s likely killing your battery as well”.
I assumed the PO would have covered this - guess not. Mr. AAA also pointed out that it may be the wrong size battery, which is interesting considering he had no idea what the car was (except that it was “cool”).
I think he mentioned anything below 15amps was too low, and the alternator was putting out 12.4
As far as batteries go, do we have a favorite, average X1/9 battery? Nothing insane, just enough to power the stock ‘74 plus maybe 200watts of upgraded stereo power.
As far as alternators go, is this like asking “what kind of oil should I buy?”
Some people like cheap, generic alternators which need retro fitting, some don’t.
I will be paying hourly for that job...so...
 
Unless you have some stuff like the lights turned on, I would not expect the car to be drawing 15 amps. Are you sure he wasn't meaning 15 volts? The alternator should be putting out between 14 and 15 volts to charge the battery.
 
dllubin said:
Unless you have some stuff like the lights turned on, I would not expect the car to be drawing 15 amps. Are you sure he wasn't meaning 15 volts? The alternator should be putting out between 14 and 15 volts to charge the battery.
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Could be, we were both masked up, and he had a slight accent, so clarity was assumed in some ways. His quote was “between 15 & 30 is normal”. I assumed amps, since a Tahoe he normally services may draw that much easily?
At the shop the other day, I had the lights, blower, stereo and hazard lights going - the windshield wipers couldn‘t continue under the load. What does that suggest?
 
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