Alternator Options

Jeff N

Jeff N

Your Mileage May Vary
So now that my son, who drove the X all summer, is off to college, I'm finally getting a lot more drive time. I've noticed now that when the headlights, windshield wipers and heater fan is on, or any combination of two of those, there's not enough juice left to power the turn signals. I've done the BWM and the headlight relay mod, as well as freshen every ground I find, but no difference. As far as I know, it has the original 45 amp Marelli alternator in it. Like a dummy, I didn't upgrade it when the engine was being rebuilt. I also tried installing LED turn signals, but couldn't get them to work right. I'm thinking now it was a low voltage/amp problem.

My question is, am I correct in assuming that installing a higher amp alternator would take care of this problem? Is the GM alternator mod worth the time, or should I stick with the Bosch?
 
Marrelli Alternators.

The problem with these alternators is the heat in the engine compartment. They all bench test fine, but once hot the output drops off. For 25 years I used a 1980 B2000 truck alternator and when it finally failed I could not locate another one. So I installed the GM alternator and have had only 1 problem and that was at FFO2008 when we drove into down town Philly in stop and go traffic and 90 degree heat. Again Heat was the problem as the diodes begin to short and stop rectifying AC current to DC required by the car's electrical System. It is a worth while mod and I am glad I made the change. The Bosch Alternator for these cars is a better unit as well, but the GM Alternator is common and cheaper. There is a 101 install on the board somewhere.

TonyK.

Grimsby Ontario Canada,
 
I have the 70a Bosch alternator, and it barely charges when idling under 1k (with any two lights/fan/wipers/AC. So, I don't think a later Bosch alternator is necessarily any better

Did you check the positive cable connections on the alternator & starter motor? Cleaning/wire brushing those contacts & retightening did make a small difference for me. Did you also check the voltage regulator (external on yours?)

I'd personally like an alternator capable of maintaining over 13.5v under load at idle.
 
I have changed several of my car with low rpm amperage to a modern turn signal relay, the old ones in most Fiats were never work well when there is a lot of draw.

My 850 with a 35 amp alternator had very slow turn signals, a stop at Autozone for a modern relay has it offering a proper signal to those around me.
 
Jeff... go here...

Do it and never look back!

http://www.network54.com/Forum/12159/message/1142890167/GM+alternator+conversion

Be sure to read my October 2008 upgrades also...

Both the Bosch and Marelli are delicate items because of theit rectifiers and regulators.

Heat is an issue for all things electrical and there are plenty of ways of keeping things cooler... but that's a whole 'nother discussion.

You can also go to an even stouter GM alternator up to 100 amps...

Let us know what you decide...
 
That is a Delco 10si or the higher current 12si, both good proven unit that are a very good value for the $. These Delco 10si & 12si alternators are also used on boats and industrial machinery. If one is going to use a Delco alternator avoid the CS130, the rectifiers are fragile and regulators can be equally fragile. Delco tried to make a smaller alternator, but ended up with a less reliable, less durable alternator.

The Bosch alternators used in EFI x1/9s are good and reliable until they wear out..about 100,000 miles.

The Marelli alternator found in 79' and some earlier cars are of a older technology, a bit fragile, wears out sooner and typical of European designed/built alternators from that era.

For now, I like the Denso alternators.. 80 amp rating (higher output is available), good voltage regulation even at idle, small size and proven reliable, very involved to convert, alternators are over $100.
http://xwebforums.com/forum/index.php?threads/9131/


Black-Tooth said:
Do it and never look back!

http://www.network54.com/Forum/12159/message/1142890167/GM+alternator+conversion

Be sure to read my October 2008 upgrades also...

Both the Bosch and Marelli are delicate items because of theit rectifiers and regulators.

Heat is an issue for all things electrical and there are plenty of ways of keeping things cooler... but that's a whole 'nother discussion.

You can also go to an even stouter GM alternator up to 100 amps...

Let us know what you decide...
Click to expand...
 
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Some good input here

But I'm still wondering, will a higher amp alternator help alleviate some of my power issues, or do I need to look elsewhere for a solution?
 
Ya know Bernice...

I looked at this again and that top adjustment bracket you made... it appears that the simple Chevy slide-arm many of us cut down and bolted to the top waterpump bolt... would work with this alternator also. Maybe a spacer (washer or two) might be needed to align it without bending... but it should work!

Just saying... Then the installation would be just as simple as the Delco version, with the cost, or possibly the weight of the Denso being the only real difference.
 
No... but it will surely help!

All the other electrical issues are a problem with the DESIGN and MATERIALS used. Load, and corrosion.

That's why a BWM, in whatever form used, and cleaning up all the grounds and connectors is a MUST. I even SOLDERED all my CRIMPED terminals in my charging circuit and picked up another .5 volts from the alternator to the battery that I was losing in the wiring run.

Secondly... a HRM mod or one of Bob Brown's no-cut conversions for the headlights, is another MUST in order to see at night!

Back to the alternators for a moment... the best voltage I ever got out of a Bosch or Marelli to the battery was about 13.8 and these alts were always fragile. (NEVER try to jump start another car with your X as you will blow the rectifier once the other car starts!) My DELCO supplies about 14.1 easily... and that .3 volts makes a big difference in recharging and the time it takes... as well as it being more robust... inexpensive, and available almost ANYWHERE you go!
 
Jeff N said:
But I'm still wondering, will a higher amp alternator help alleviate some of my power issues, or do I need to look elsewhere for a solution?
Click to expand...

Actually even a 45 A alternator should be able to power the systems with no issue. The problem with X1/9s is "IR" losses at the connectors and insufficient wire gauge. ...and a higher output alternator won't fix those.

I suspect either the alternator you have is not putting out what it should, or, you have some more electrical system sleuthing to do (clean connections and upgrade wire).

I've "fixed" many an electrical problem with my X (both past and present) doing nothing more than cleaning up connections.

Good luck.
 
Actually, no.

A new more powerful alternator might help, but the symptoms you describe point to poor conductivity. Clean and tighten the grounds. Clean and tighten all junctions.

If LEDs wouldn't work (very little load) then the problem isn't load per se. You probably have poor grounding at the lights. Changing the thermal flasher for an electronic one would also help. The old flashers depended on the current passing through the circuit to heat up a bimetallic spring contact and cause it to open. If the circuit is flowing current poorly, the contacts can be slow to operate.

When using LEDs, you have to use a different flasher anyway, unless they're designed to use a normal flasher which is unlikely.

When you have all of your accessories on, does the red alt light glow? If not then the charging system is sufficient. If so, then you may need to go through things and clean and tighten the connections. From battery to bulbs. And do the BWM to provide more power to the acessories.

There are grounds located throughout the car, in the headlight recesses, under the left side dash, in the engine bay by the coolant tank, in the rear trunk around the lights.
 
Indeed Tony, a simple flat steel arm would definitely work and make little difference in function as required. If this was a production item, it would not likely pass design review meetings.. Regardless, I like it and this is the way I do hobby stuff and it is far easier to adjust the belt tension by simply turning a hex on the end of a threaded rod than levering the alternator, then tightening the bolt.

Most every every car hobby project has gone this way, I use aero spec hardware any place possible and over design and build stuff just because I can. The most recent project on the TR6 is design and building the entire wiring harness from scratch.. Using the stock wiring harness would be fine or even replacing it with an aftermarket one would be even better, but no, we designed it from scratch, then will build it with EE insulated Teflon wire, brazed barrel crimp terminals made by 3M and proper crimp tools, aero spec circular connectors and any questionable electrical bits replaced.

I'm just not tolerant of anything that will fail for any reason.. maybe I just don't like being stranded anywhere or ?, regardless, I'm going go beyond what is required to make sure it's not going to fail beyond the designed requirements.

Bernice

Black-Tooth said:
I looked at this again and that top adjustment bracket you made... it appears that the simple Chevy slide-arm many of us cut down and bolted to the top waterpump bolt... would work with this alternator also. Maybe a spacer (washer or two) might be needed to align it without bending... but it should work!

Just saying... Then the installation would be just as simple as the Delco version, with the cost, or possibly the weight of the Denso being the only real difference.
Click to expand...
 
+1

More alternator capacity will not cure connection problems.. which is the source of electrical problems in many older cars.

Over time, the spade connectors used on most ever car from that time and many cars produced to this day are marginal from day one. The problem with them, the connection is not gas tight and being made of brass and plated with tin, tends to loose contact pressure due to thermal cycling resulting and corrosion develops between the spade connections increasing contact resistance which causes the connection to get hot and further increasing the thermal cycling of the connection and speeding up it's process to failure.

I will avoid spade type connections if possible when re-doing any wiring in any car.

This also applies to every bolted to the chassis ground star found in the X. The bolted connection will develop corrosion within the joint and cause problems with grounding.

http://www.caig.com/ makes contact cleaners and contact compounds that can help connection reliability.

And, know most of the current travels into and out of the ignition switch.. this connection is critical. If the switch or any of it's connections is in anyway marginal, problems will be assured. Definitely do the BMW, it helps.

Oh, if one does increase the alternator capacity due to higher power lighting or etc.. and does not consider where this extra current goes, there will be problems..big problems.

Bernice

Jim W said:
Actually even a 45 A alternator should be able to power the systems with no issue. The problem with X1/9s is "IR" losses at the connectors and insufficient wire gauge. ...and a higher output alternator won't fix those.

I suspect either the alternator you have is not putting out what it should, or, you have some more electrical system sleuthing to do (clean connections and upgrade wire).

I've "fixed" many an electrical problem with my X (both past and present) doing nothing more than cleaning up connections.

Good luck.
Click to expand...
 
I think...

I think it means you can have all the extra voltage or amperage you want, but if your connections are bad, it could cause problems or simply not fix the problems you're trying to correct.

Kind of the point I was trying to make as well.
 
Perhaps the higher amp/ greater heat would be of concern. After reading a little on this, as you go up in amperage output, heat generated grows significantly. I can't see any consumption side issue, as you point out, the system will simply use what it needs, surely?
 
Yes but...

The resistance will continue to grow until the wires or connection fail. The extra power going through a corroded connection will create heat, which will add resistance, causing more heat and so on.

This could get ugly if say, the alternator connection to the battery is loose or corroded. The alternator would increase its output but less and less would get to the battery. The alternator, through the feedback circuit would see that not enough power is getting to the battery, and the output would increase.

Not china syndrome stuff, but could cause a fire on such an unfused circuit.
 
Yes and...

When they separate with a high amperage load an arc is created, which can ignite wire insulation, plastic connector blocks, oil residue (never seen that on a Fiat, eh?) etc.

Not to mention wear and tear on the alternator components.
 
PROBLEM SOLVED!

So I took the advice and cleaned up the contacts on the connector from the alternator harness and saw some improvement. I also freshened up the tail light assembly grounds, both of which apparently were enough to make the difference for the LED's I had previously purchased but couldn't get to work right before. The biggest difference, however, was installing a new electronic flasher module. HUGE DIFFERENCE! The amp meter barely budges at all after installing it. I used a Bussman #BP233, which was a simple plug in replacement. :thumbsup: :thumbsup: :headbang: :dance2: Two big thumbs up, a headbang, and a victory dance!

I finished it off with the LED turn signals up front and now have LED's all around, with the exception of the clearance lights. The amp's still dip quite a bit when the headlights, fan and wipers are on, but at least I know it's not going to affect the taillights/turn signals now.
 
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Very good to hear! A plug in replacement for the old style relay sounds much easier than what I just did :rolleyes:, but that's OK, I still need to up the ratio of Volvo to Bertone parts in the car :laugh:
 
I was going to mention it, but didn't want to hurt your feelings after putting so much work into your mod. :eek: It was a very nice write up anyway.
 
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