Author Topic: Voltage Regulator dead?  (Read 9184 times)

col320ce

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Voltage Regulator dead?
« on: June 25, 2016, 15:01:04 »
I have a 1964 230SL manual Australian delivery with a Bosch RE55 voltage regulator. The battery isn't charging properly but unfortunately the car hasn't run for some time and the engine is in bits (so can't do any live tests). The voltage regulator has red stuff dripping from it (I'll post photos tomorrow but its dried hard). Alternator "looks" like it has recently been reconditioned (as most things were done 10 years or so ago).
Is this the correct voltage regulator and is the red ooze coming from it a sure sign that it's the culprit?
Thanks for any help...
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline

col320ce

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Re: Voltage Regulator dead?
« Reply #1 on: June 25, 2016, 15:07:41 »
Here are some pictures...
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline

Tyler S

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Re: Voltage Regulator dead?
« Reply #2 on: June 25, 2016, 15:34:25 »
That looks like a replacement regulator. It also looks like the connector was replaced with crimp spade terminals. Could very well be your problem, esp with it looking to be overheated. The original regulator would have had a metal housing. Beru makes an aftermarket regulator that works well if you cant find an original-also costly Bosch. When you get it back together with a new regulator you will need to test the alternator to make sure its not going to damage the regulator again.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

col320ce

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Re: Voltage Regulator dead?
« Reply #3 on: June 26, 2016, 09:08:41 »
Thanks for your help. I'll get the beru. The new one however has 3 terminals...  Mine has 2...  I'll try to find a wiring diagram to see if I can work it out.
Thanks again...
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline

Tyler S

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Re: Voltage Regulator dead?
« Reply #4 on: June 26, 2016, 16:12:43 »
Col, It should have 3 terminals. I didnt catch that on the pic. Wrong type regulator. It appears the brown ground wire is missing. That is the 3rd wire. Hopefully it didnt take out the rectifier in the alternator.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

col320ce

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Re: Voltage Regulator dead?
« Reply #5 on: June 26, 2016, 22:11:16 »
Hi Tyler
There is a ground wire beside the unit... I'll take a photo to show you.  Hope that's it.
Thanks again
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline

col320ce

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Re: Voltage Regulator dead?
« Reply #6 on: June 29, 2016, 13:34:44 »
So .. my head gasket has gone.  Took it to be repaired and the chap said that there has been some electrolysis occurring damaging the head. So I'm looking for a stray current (when I get the car back together).  I'm not sure if the dead looking voltage regulator is the cause or the result of this.  Either way it's made the cylinder head repair expensive.  >:(
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline

Tyler S

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Re: Voltage Regulator dead?
« Reply #7 on: June 29, 2016, 14:19:40 »
It could be electrolysis but more than likely the cause was ph of the coolant went bad and caused the corrosion.
1968 (67) 250sl. 4 speed manual. DB180 Silver
1955 220 Cabriolet A. White Grey
2019 E450 Wagon. Majestic Blue
1936 Ford PU Flathead V8. Creme on tan interior.
1989 Volkswagen T3 Westfailia Campmobile. Dove Grey (blue)

col320ce

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Re: Voltage Regulator dead?
« Reply #8 on: July 02, 2016, 10:51:08 »
I'll make sure all the grounds are good and I'll make sure the coolant is correct.
New regulator on order.
Thanks...
Col

1964 230SL
1965 250SE coupe
1993 320CE Sportline

Meiang

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Re: Voltage Regulator dead?
« Reply #9 on: November 16, 2016, 13:22:12 »
A bit late to reply but I only just joined today.

As others have mentioned you need a 3 terminal regulator which would be a Bosch RE57 not a Bosch RE55 as you have fitted (see attached catalogue pictures). With the RE57 no connector change from the original is required.

The RE57 (Australian Made) is still available on Ebay is is a very high quality item.  It costs around US$35.

Montreal V8

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Re: Voltage Regulator dead?
« Reply #10 on: November 16, 2016, 18:44:20 »
In a previous post I said I had been running a Bosch RE 55, which was incorrect, as it was actually RE 57  part # 9 190 067 010  (Sorry). I've been running three of these, two on cars, and one on a bike, and they seem to be foolproof. As mentioned on the above post, these are a direct replacement, and were readily available on Ebay Aus.    Cheers,   Dale.