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Posted by: Brian Fuerbach Oct 12 2022, 01:53 PM

I have a Bosch solid state regulator and have been noticing low and erratic charge rates lately. Swapped it for a nos Bosch mechanical reg that I had in my stash. Charge rate is 13.8-14v now, perfect but, the mechanical regulator gets pretty warm after running for awhile. I measured the case at 130F. Is this normal for a mechanical regulator?

I would like to get a solid state replacement but the Bosch regs cost almost $400. What gives? did they stop making them?

What is the currently recommended replacement?

Posted by: johnhora Oct 12 2022, 03:11 PM

check with Mark...he has had new solid state and mechanical

@http://www.914world.com/bbs2/index.php?showuser=3457

Posted by: emerygt350 Oct 12 2022, 03:25 PM

I have the hella solid state. Has been flawless and inexpensive.

Posted by: 914Sixer Oct 12 2022, 04:15 PM

I have two NOS solid state Bosch left. I can do $124 shipped for one. Agree that the prices are stupid for these. You might check your relay board, may be corroded under tar causing relay to heat up.

Posted by: Olympic 914 Oct 12 2022, 07:00 PM

Am using a BERU solid state,

inexpensive and works fine. may have to modify mounting holes.

Posted by: DC_neun_vierzehn Oct 12 2022, 08:36 PM

@Brian_Fuerbach

I still have a couple of NOS Bosch for sale:

http://www.914world.com/bbs2/index.php?showtopic=359337&hl=

$65 shipped

Posted by: Van B Oct 12 2022, 09:02 PM

Hella didn’t work on my car at all. I’m surprised to hear of someone that was able to use it actually

Posted by: porschetub Oct 12 2022, 09:09 PM

undo the relay board and turn it over,if it's getting that hot the tar underneath may be melting,check all the large diameter positive wires for insulation heat damage also.
Firstly check your heatgun ?.

Posted by: Brian Fuerbach Oct 12 2022, 10:08 PM

I will pm you on the solid state reg. The ST reg I removed does NOT get hot, it just charges low at 13.2v max unloaded.

The mechanical reg I replaced it with is new and was purchased a few years ago from a world member but never used. This mech reg gets hot but charge rates are correct.

So a mechanical reg is not to supposed to get hot?

Posted by: Brian Fuerbach Oct 12 2022, 10:39 PM

I looked at the bottom of the relay board and and it looks really good but the original solid state reg did not get hot. The mechanical replacement is getting hot. I measured the 130F with a Ratech IR non contact thermometer that has been recently checked against some known values so I believe it is correct. The reg seems to top out at 130 which was confirmed every time over a couple of drives. I have read on the google that “mechanical” regs act as heat sinks in their process of regulation.

Anyone have a “Bosch mechanical” reg that can confirm running temp? At least touch.

Posted by: StarBear Oct 13 2022, 06:10 AM

Van; yes, a few of the standard electrical replacement parts don’t work in some of our 1.8s yet do work in others’. Alternate flasher relays and Petronix just don’t work in mine. We’re special….

Posted by: Lockwodo Oct 13 2022, 07:47 AM

Wondering if anyone has had this problem before. Car is a '74 2.0. Replaced voltage regulator with a new Hella unit. At 1000 rpm idle, voltage measured at the battery terminals was initially steady at 14.5 volts (too high), and now is fluctuating from 12.5 to 16.5 volts. Is that likely a bad regulator or could a problem elsewhere in the charging system produce that fluctuation?

Posted by: Van B Oct 13 2022, 09:10 AM

@http://www.914world.com/bbs2/index.php?showuser=10753 the Petronix works beautifully in my car. I can literally see the difference on the timing mark; rock steady.

But my experience with the budget Hella unit was exactly as @http://www.914world.com/bbs2/index.php?showuser=26193 described. I now have two Bosch solid state units. The old style solid state delivers 14.29v consistently per my cheap multimeter. The new style gives 14.00v constantly. The only caveat I have is that both require a little throttle bump to get the voltage light to extinguish if you have a sluggish start in real cold weather.

Posted by: jim_hoyland Oct 13 2022, 09:28 AM

Forgot the brand, but I found an adjustable VR
Been in the car 10+ years
I’ll pull it and get a pic when I return home

Posted by: Lockwodo Oct 13 2022, 09:36 AM

Posted by: porschetub Oct 13 2022, 12:30 PM

had issues with the Hella repop from Pelican ,with my newly reconed Bosch altenator ,bought a NOS Bosch one of Mark an all is fine.seem to remember they need to me matched by the sticker in the 911 enginebay.

Posted by: Geezer914 Oct 13 2022, 03:16 PM

I purchased a mechanical Bosch regulator from Brian and tweaked it to put out just over 14 volts. You need a loose .012 between the contact points.

Posted by: Brian Fuerbach Oct 13 2022, 06:49 PM

What temperature does it get up to. Hot to the touch or cool?

Posted by: windforfun Oct 13 2022, 07:33 PM

Why would this increase the output voltage?

Posted by: Highland Oct 14 2022, 09:57 AM

This is what I used. Less than $30 from Autozone. Worked for the last 2 years, but only ~1500 miles.

Posted by: worn Oct 14 2022, 03:40 PM

Went to a site specializing in old Volvos. The stock regulators seemed to crap out when I would turn on the lights or anything equally reckless.

Posted by: jim_hoyland Oct 14 2022, 07:30 PM

See: https://www.ipdusa.com/products/6781/Adjustable-External-Voltage-Regulator-Alternator-Models-for-Volvo-Aftermarket-IB301A-105443

This the one I’ve used for 15 years….


Attached image(s)

Posted by: Lockwodo Oct 15 2022, 11:50 AM

Probably a dumb question, but you're using this on a Volvo, right? The website didn't show an option for 914. Another question, how do you adjust it? Is there some sort of adjustment screw and do you have to pull the VR out to adjust it?

Posted by: Lockwodo Oct 15 2022, 12:11 PM

Hmm, so the voltage regulator saga continues.

After the mechanical Bosch VR on my 914 crapped out, I bought a Hella VR and installed it. Voltage at the battery was 12.6 volts (ignition off) and 14-17 volts (1000 rpm idle). So the voltage at idle was way high and fluctuating. The vendor agreed to send a replacement Hella VR.

Installed the second Hella VR and voltage at the battery was 12.6 volts (ignition off) and 14.8 volts (1000 rpm idle) with minimal fluctuation.

Two questions for you guys:

1) is anything over 13.6 volts at 1000 rpm idle too high? I've seen at least one website indicating that voltage over 13.6 volts at idle could cause electrical component failures.

2) at 1000 rpm idle, how much voltage fluctuation is OK? With the first Hella VR and all the fluctuation it caused, it engine seemed to run unevenly over 1000 rpm.

Thanks!

Posted by: jim_hoyland Oct 15 2022, 02:35 PM

It on the 914

Posted by: Lockwodo Oct 20 2022, 06:15 PM

Hi all. I wasn't getting any joy from the two Hella voltage regulators I tried (see post in string above), so I decided to buy one of the adjustable VRs mentioned by Jim Hoyland. I bought this one on Amazon (manufacturer and OEM # IB301A) for $35:

https://www.amazon.com/dp/B014GN1YLK?psc=1&ref=ppx_yo2ov_dt_b_product_details

Out of the box, the charge rate was 14.1 volts at idle. I turned the adjustment screw counter clockwise to set the charge rate at 13.7 volts. I will have to modify the bracket on the VR because the holes don't line up with the relay board mounting holes (same issue as with the Hella VR). Liking it so far!