home register FAQ memberlist calendar

Go Back   Turbobricks Forums > Mechanical > maintenance & nonperformance

Reply
 
Thread Tools Display Modes
Old 06-04-2020, 07:24 PM   #26
ogamer777
Loading...
 
ogamer777's Avatar
 
Join Date: May 2016
Location: New North Winchestersonville (PNW 425 gang)
Default

Quote:
Originally Posted by bobxyz View Post
I thought about this a bit more and it still seems like it must be a bad diode in the alternator(s). The wiring is simple enough - ground cable, +12 to battery via starter, and D+ exciter wire to dashboard indicator lamp. The lamp going on and off, and the voltage measurements with dashboard connector unplugged seems like the D+ wiring is correct.

The usual cause of bad diodes is trying to charge a completely dead battery, or trying to jump start it with reversed jumper cables. Either one causes very high current draw through the alternator. When starting it, are you using the (charged) battery in the car or jumping it? The sparks when reving it from idle sounds like the alternator is trying to put out max current once the revs, and alternator output voltage, go up a bit.
The battery is fully charged. I took it out of my 244. I havenít jumped it with this current alternator installed. The last denso I might have; I canít recall. But the current setup had no problems starting up the engine. Leaving the battery hooked up for a while drains it, so I have it disconnected when Iím not trying to diagnose this problem.
__________________
84 242 DL M46 212000Mi
82 244 GLT (15G) M46 243500Mi 23 Aug 2019
79 242 GT 1 of 600 Aussie RHD BW55 312223Km
83 245 TURBO M46 "117000Mi"
/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\
81 264 GLE M46 105k

Feedback thread: http://forums.turbobricks.com/showthread.php?t=322924
ogamer777 is offline   Reply With Quote
Old 06-04-2020, 11:09 PM   #27
ogamer777
Loading...
 
ogamer777's Avatar
 
Join Date: May 2016
Location: New North Winchestersonville (PNW 425 gang)
Default

Okay so I ended up throwing the old Bosch alternator in and wham bam kazam, works great no sparks or amp light.

So now my question is this: is a ‘79 not compatible with a 100A swap? Seems odd that two good working ND alts died in between bench testing them and installing them in the car.
ogamer777 is offline   Reply With Quote
Old 06-05-2020, 02:30 AM   #28
John242Ti
LH-Jet & Carb Free Zone
 
John242Ti's Avatar
 
Join Date: May 2003
Location: Duvall, WA
Default

^We still need to try one of them in one of your other cars. I'd recommend, now that the 242 is on the ground, that we try one in the 244, since it, like the 242, is K-Jet. I expect it to play nice with the Denso, like my cars do, but it'd be a good idea to check. In some respects, I do wish I'd picked up that '80 GT last fall. We could try one in it and see if, like yours, it has the same problem.
__________________

1982 242Ti - black, M46. 1985 245Ti - blue, M46.

@1982_volvo_242_turbo on IG
John242Ti is offline   Reply With Quote
Old 06-05-2020, 10:43 AM   #29
bobxyz
Board Member
 
bobxyz's Avatar
 
Join Date: Aug 2014
Location: Boulder CO
Default

Glad that it's working again, but I agree that it's weird that the densos failed.

AFAIK, there should be no problem running a 100A on an older car as long as it has a normal battery and the battery cables are properly tightened. The battery buffers out any voltage/current surges as accessories or other electrical loads turn on and off. Without the battery, a bigger alternator will cause bigger surges, but I'd be surprised if alternator damage could result.

One other question - did you attach anything to the back of the denso using a bolt that goes into the housing, for instance, a cable clamp? If so, maybe the bolt is too long and is shorting out something within the alternator. At least on the Bosch installs that I've seen, the cable clamp goes under the ground stud.

Also look carefully if the D+ spade connector on the denso could have been bent over far enough to short out to the housing.
bobxyz is offline   Reply With Quote
Old 06-05-2020, 01:33 PM   #30
ogamer777
Loading...
 
ogamer777's Avatar
 
Join Date: May 2016
Location: New North Winchestersonville (PNW 425 gang)
Default

Quote:
Originally Posted by bobxyz View Post
Glad that it's working again, but I agree that it's weird that the densos failed.

AFAIK, there should be no problem running a 100A on an older car as long as it has a normal battery and the battery cables are properly tightened. The battery buffers out any voltage/current surges as accessories or other electrical loads turn on and off. Without the battery, a bigger alternator will cause bigger surges, but I'd be surprised if alternator damage could result.

One other question - did you attach anything to the back of the denso using a bolt that goes into the housing, for instance, a cable clamp? If so, maybe the bolt is too long and is shorting out something within the alternator. At least on the Bosch installs that I've seen, the cable clamp goes under the ground stud.

Also look carefully if the D+ spade connector on the denso could have been bent over far enough to short out to the housing.
The battery is your average interstate brand battery and itís only a year or so old, if that.
I didnít use any cable clamps, the ground and power wires have ring terminals and the exciter wire, a female spade connector. The D+ terminal is perfectly straight.
ogamer777 is offline   Reply With Quote
Old 06-05-2020, 02:11 PM   #31
dl242gt
Happy playing the blues
 
dl242gt's Avatar
 
Join Date: Jun 2002
Location: S NJ, a suburb of Phila.
Default

In reading the thread it reminded me of a failed denso I had. It was a 'rebuilt' alternator from an ebay selling. It worked fine at first on my 93 wagon. Then after about a year I started hearing a weird scraping whirring noise. The bearings were very cheap crappy bearings and they had failed. This let the internal cooling fan scrape on the inside of the alternator housing. If you have worn bearings in your alternator. It could let the internal fan scrape and make sparks.

Just a thought.

I've been running denso alternators on kjet cars for over ten years and I also put one on my 93 wagon. When you installed the denso did you move the upper bracket to the front of the alternator and use the spacer and longer mounting bolt for the upper bracket mounting? You can also update to the upper bracket with the adjuster on it for easy tensioning.
__________________
Dave,
1982 242 turbo. 340k miles. MVP coilovers and 3" exhaust. Flowed 405 with a V15. Cossie turbine housing with upgraded compressor housing. 90+, IPD remote oil filter. Some other goodness, too. Been lots of fun over 25 years. Restored in 2k. Now ready for a 2nd restoration.

1993 245 Classic, 430k miles, enem V15. IPD bars and chassis braces. Simons sport exhaust from Scandix. sbabbs ezk chip. Been a good road warrior. Genuine Volvo rebuilt leaky M47.
dl242gt is offline   Reply With Quote
Old 06-05-2020, 02:25 PM   #32
bobxyz
Board Member
 
bobxyz's Avatar
 
Join Date: Aug 2014
Location: Boulder CO
Default

Clearly you must have riled the Old Norse gods of K-Jet. You'll need to ask the experts here what a suitable sacrifice is to restore their good graces.

If you want to take apart a Denso, see:
https://www.volvoclub.org.uk/faq/Ele...nsoRebuild.htm
https://forums.turbobricks.com/showthread.php?t=349853
bobxyz is offline   Reply With Quote
Old 06-07-2020, 11:47 PM   #33
ogamer777
Loading...
 
ogamer777's Avatar
 
Join Date: May 2016
Location: New North Winchestersonville (PNW 425 gang)
Default

Quote:
Originally Posted by dl242gt View Post
In reading the thread it reminded me of a failed denso I had. It was a 'rebuilt' alternator from an ebay selling. It worked fine at first on my 93 wagon. Then after about a year I started hearing a weird scraping whirring noise. The bearings were very cheap crappy bearings and they had failed. This let the internal cooling fan scrape on the inside of the alternator housing. If you have worn bearings in your alternator. It could let the internal fan scrape and make sparks.

Just a thought.

I've been running denso alternators on kjet cars for over ten years and I also put one on my 93 wagon. When you installed the denso did you move the upper bracket to the front of the alternator and use the spacer and longer mounting bolt for the upper bracket mounting? You can also update to the upper bracket with the adjuster on it for easy tensioning.
I am beginning to think the last ND alt I had in there had dry bearings but still am stuck on the fact that it was working in another vehicle great.

I was using the later style adjuster bracket.

Quote:
Originally Posted by bobxyz View Post
Clearly you must have riled the Old Norse gods of K-Jet. You'll need to ask the experts here what a suitable sacrifice is to restore their good graces.

If you want to take apart a Denso, see:
https://www.volvoclub.org.uk/faq/Ele...nsoRebuild.htm
https://forums.turbobricks.com/showthread.php?t=349853
I am honestly afraid, now, that something might get damaged if I try a ND in there. The old Bosch unit is working just fine, albeit, a little under load with the lights on and heater on full blast.
ogamer777 is offline   Reply With Quote
Old 06-08-2020, 12:57 PM   #34
VB242
F*ck 12
 
VB242's Avatar
 
Join Date: Sep 2011
Location: In my 15x20 Corona cell
Default

I've been running a 100amp ND for years on my 1980 242.
__________________
"i will destroy all of you!"
-Sheldon Plankton

Booty Scooty
https://youtu.be/i4oAOZ8nbq4
VB242 is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


All times are GMT -4. The time now is 09:47 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, vBulletin Solutions Inc.