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Discussion Starter · #1 ·
Hello, Swedespeed 1800 subforum!
I've been around the Volvo world for a while, and have just recently purchased a lovely 1970 1800E in excellent overall condition.

This will be my daily driver, so I am looking to make some updates.
The subject of this e-mail arises due to the fact that I will be carefully and methodically installing a modest audio system into the car. The amplification max fuse rating is around 80A - not much by modern audio standards, but likely more than the capacity of the factory alternator. I will be directly wiring the amp power circuit from the battery terminals, and the head unit (no amplification) will be powered by the factory power supply.

So, with that context, on to my question.
What are the recommended alternator options (if any) with 100+ Amp capacity? I installed one of Philski's (Turbobricks) 850 100A Bosch units in my '79 245 and it was a seamless swap.
I'm not familiar with the 1800, so I figured I'd reach out to see if anyone here may have some experience.

Thanks for any and all responses.

Warm regards,
Scott
 

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Check out the SWEDISH EMBASSY (not the Swedish Embassy) web site for alternator info

http://www.sw-em.com/

If you don't have air conditioning the original alternator will be 35 amps. I think AC models got a 55 amp Bosch which is a drop in replacement for the 35. Whether you go 55 amp or bigger, you will have to rewire the + supply out of the alternator if it was originally a 35 amp alternator because it will not be adequate for anything larger.

As an observation, with audio systems the current consumption is highly variable with average current consumption being way, way below the potential peak levels. Otherwise you would be deaf in short order. That peak current demand is supplied by the battery, not the alternator (the alternator cannot respond fast enough). The alternator deals with the average current consumed by the audio system. Unless you are driving around at night for several hours with the headlights on, the heater fan running and the stereo turned up really loud, the 35 amp alternator will probably be able to manage the average load just fine. However, if you feel the need to upsize, go for it.
 

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Discussion Starter · #3 ·
Check out the SWEDISH EMBASSY (not the Swedish Embassy) web site for alternator info

http://www.sw-em.com/

If you don't have air conditioning the original alternator will be 35 amps. I think AC models got a 55 amp Bosch which is a drop in replacement for the 35. Whether you go 55 amp or bigger, you will have to rewire the + supply out of the alternator if it was originally a 35 amp alternator because it will not be adequate for anything larger.

As an observation, with audio systems the current consumption is highly variable with average current consumption being way, way below the potential peak levels. Otherwise you would be deaf in short order. That peak current demand is supplied by the battery, not the alternator (the alternator cannot respond fast enough). The alternator deals with the average current consumed by the audio system. Unless you are driving around at night for several hours with the headlights on, the heater fan running and the stereo turned up really loud, the 35 amp alternator will probably be able to manage the average load just fine. However, if you feel the need to upsize, go for it.
Thank you!
Yes - I do agree that the music system is not likely to pose much of a draw, as I listen at reasonable levels. I think I'll do a phase I install of the audio side and assess how the voltage is doing, and can upgrade if needed. The car does not have AC.

Thanks again, and thank you for the link!
-Scott
 

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Scott;

A good original equipment Alt option for a non AC 1800 would be to replace the 35A standard Alt with a ~60A as used in the factory AC equipped cars...but that would still use an old (ancient!) mechanical relay regulator...next better would be a modern internally electronic VReg equipped Bosch rated at ~80 (PLENTY of output power!, and that includes for your super groovy high power audio system!)...and that is about the limit for the single Fanbelt, because IT must transfer (mechanically) all the energy when Alt is under Maximum load...I specifically recommend against installing an Alt of ANY manufacture rated at a higher output for the reason above...don't do it! See: https://www.sw-em.com/altkit_additional.htm#Installing_a_100A_Alternator

As an alternate solution, and one we developed because the Bosch units are a lot more expensive than the much more common Delco units on this side of the Atlantic, the SW-EM Alt conversion, using a ~60A Delco Alt, and those Alts have PLENTY of scroat for all but the highest power requirements, including Audio systems (read: more than 1000W!)...read on...

"The amplification max fuse rating is around 80A" ...that works out to roughly 1000W...one tenth of that is enough to make your ears BLEED if it was a continuous audio power, so as 142G quite correctly notes, and I can only reiterate and highly emphasize this(!), that fuse rating is sized for the (very) short-term currents which would flow (when you're showing off and that only on Bass Peaks).

I recommend you install a ~60A Alt of the manufacture and vintage, and cost, and amount of work, of your choice, which will supply all of your vehicle's elec needs, connect and supply the audio sys power from the Battery terminal with that 80A fuse they recommend, and be done with it!

Super high power sound systems operated for contests by remove control (because you wouldn't want to be in the car at those volumes), are typically powered by soupcan capacitor banks, capable of delivering ridiculously high currents for short term...I'm not interested in those, and if you are, I probably can't help you at all...

Cheers

142G; Thanks for the reference!

Edit...PS; Many high power sound systems draw significant power even when OFF(!), including when car might be parked(!!)...check this current before thinking Battery has a problem, leading to overnight discharge. See: https://www.sw-em.com/Battery Notes.htm#overnight_battery_discharge
 

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Ron:

The only reason I had mentioned the 55 amp Bosch was because it would mechanically be a drop in fit replacement for the 35 amp alternator (notwithstanding the need to upgrade the wiring). Rebuilt Bosch 55 amp alternators for the 140 / 1800 are pretty cheap from Rock Auto (< $70). In fact, rebuilt 35 amp alternators seem to be in very short supply. One up-side to the Bosch alternators is that they have a lot of steel and copper in their frames. The net effect is that at low RPM (idle) they actually produce more current than some higher rated alternators. Check the output curve of some of those tiny high capacity alternators and they look pretty pathetic.

Yes, it does use the external electromechanical voltage regulator which, if it is still the original 1970 regulator should probably be up for replacement. I replaced my original regulator with one of those solid state regulators from Dave Barton and after set up it holds my voltage at a nice steady 14 volts from idle on up. For me the external regulator has a side benefit because I have the stupid Patriot header and the #1 runner is positioned very close to the back of the alternator. Even with a heat shield, its nice to have the electronics somewhat separated from the body of the alternator.
 

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Discussion Starter · #6 ·
Great feedback, guys - very much appreciated.
Ron - the other day I followed the link that 142guy provided, and saw the product you describe. It looks like a good solution. I'd love to hear more about tradeoffs (fit, etc), if any with this unit.
I've also seen the 55A units at Rockauto, as well as the voltage regulators - seems like another solid option.

I'm definitely not one of those bass hound kids - more an audiophile if anything. I have a sealed cabinet subwoofer (rather than panel rattling ported) with modest specs. I just want to have good quality sound, with the occasional sing along at some higher level (not deafening).


Thanks again,
Scott
 

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Hey, I have a 1971 1800E that was A/C equipped, but only had the 35A alternator. I'm not sure if it was originally 55A and somebody put in a 35A or if that's what it came with. I recently put in the Bosch 55A, a new regulator and upgraded the wire to the starter to 8 gauge and it seems to run and charge great. I almost fried the 12 gauge wire in the original harness so make sure you upgrade the wiring. I have the original radio in my car so I can't tell you how it would do with a modern audio system.
 

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I recently upgraded to a 63 AMP 1-wire: https://smile.amazon.com/gp/product/B0081S9C16/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I tried to modify my original (not quite factory) bracket, spent several days and a few trips to the store, then ordered the bracket from sw-em and had it in within 10 mins. Cost more than the alternator, but worth every penny.

The 1-wire alternator was easy to hook up, and the engine bay looks so much cleaner.

I went with 63A because my car had AC, and I may re-install it at some point. I also have an aftermarket stereo system. Pretty mild by the standards I had in my teens, but likely a bit louder than most other P1800s. :) A 4x50w Alpine amp + an 8" sealed sub.
 

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Based upon my 140 experience, the 55 amp is not covered in the factory service manual. All the FSM described were the Bosch and SEV Marchal 35 amp alternators. The parts manual lists three alternators - parts # 419420, 460085 and 241527 and according to the parts manual these are just due to production changes - they change as the VIN number gets bigger. There is a 4th alternator, 462893; but, there are no details in the parts manual on its application. Perhaps that is the Volvo part # for the 55 amp alternator?

Since the air conditioning was a dealer installed option perhaps the 55 amp alternator was an optional option if you were installing air conditioning?
 

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I know that this is a bit off-topic, but I have found a great way to have plenty of power. I cheat.
I added a small trickle charger (battery tender) permanently attached with the plug easily available at the fender.
I also have a GPS tracker in the car that will begin to kill the battery if I don't drive it for a week - so I kinda need it.

Now, whenever I get in the car, I have a 100% fully charged battery. Cranking is soo much more forgiving when the battery is fully topped off. I do not have AC though...

I have installed a Custom Autosound Bluetooth car radio that looks retro with old push buttons. I just looked - and it is 300W. I never turn it up that much at all. I am very happy using bluetooth with it - but do not expect an easy to figure out system. It is kinda screwy if you use FM, etc a lot. Basically, I get in the car and it connects to Pandora on my phone. The left knob is volume, the right knob skips to the next song. I really am not sure how to use fm, etc. Bluetooth is all that I wanted. I cannot say the sound is awesome, but all I have is a few good speakers in a box under the rear window. I have hands free phone too! It works really well.
 

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Breaker;

At least you realized that the tracker poses a continuous current drain on the Battery, and accommodated that, instead of thinking it was the Battery itself not holding a charge...another option to replace "Phantom Current" or Stand-by Current is to install a small solar panel (obviously this doesn't help much when car is parked in the garage , so your trickle charger is again a good solution [...and I wouldn't call it "cheating"])...

Note...some high power audio amps are also often current pigs, drawing significant stand-by power...WHEN OFF, and doing NOTHING!!! ...so don't wire it to a Battery Power source, but to an Ignition Power source, because it's "power" switch may only be controlling the audio and not the actual power to unit. Some Audio base units also have a slave power lead available which can be used. See also: https://www.sw-em.com/Battery Notes.htm#overnight_battery_discharge

Cheers
 

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A little off topic from the OP, but they do call them threads and this one has meandered this way ....

I use a Negative battery post disconnect on ALL my cars, (except for the XC90 T8)

I disconnect the battery EVERY time i put the old Volvo's away as I may not drive it for a couple of weeks. I even have one on my 2010 Ford Truck and I disconnect it when leaving the truck park for more than a week. After I drive the battery is charged and the disconnect assures that it stay that way for a few weeks.

10 bucks at any local autoparts supplier and well worth it, 3 minutes to install.

Yes it is a PITA if you have the Radio stations and clock programmed on the display, but well worth it. I'm not sure if the Retro Looking BlueTooth units store the users phone pairing information in non volatile memory, that could be a NO GO if it does as setting that up everytime would be a showstopper, but I never rely on the clocks anymore (even in the truck) and only listen to 2 radio station,

On my old Volvos and as Ron states, phantom currents draining the battery really spoil a Sunday morning Drive when you have to wait an Hour to recharge the battery (not to mention the additional stress and sulfation on the battery plates)
 
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