| Author |
Message |
Michael N. (Man90tr)
Member
Username: Man90tr
Post Number: 729
Registered: 4-2001
| | Posted on Monday, December 02, 2002 - 3:50 pm: | |
Hey guys,
I apologize for being slow on my update on the alternator issue. The long and short of it is I took the advice of everyone here and of a gentlemen I met at the Cavallino show who stated "the biggest thing about the TR is vibration from the road wreaks havoc on the various plugs and clips". With that in mind, I spent 10 minutes, unhooking and rehooking all visible wires and clips around, to and associated with the alternator. Well, that was exactly 5 weeks and 2,431 miles ago. Yes, it was a beautiful month for driving here. The car drove perfectly without a hitch. The car just left on Horseless Carriage for Florida where I meet her in 2 1/2 weeks. Thanks for your help everyone and Steve thanks for the schematics-- even though I did not need them I have them for future reference. And yes, James the belt was tight.
Thanks again,
Michael |
Michael N. (Man90tr)
Member
Username: Man90tr
Post Number: 706
Registered: 4-2001
| | Posted on Sunday, October 27, 2002 - 2:43 pm: | |
Thanks everyone. I will start with the simple things first and then move on from there. I will post an update in a week or so.
Michael |
Harry (Harry)
New member
Username: Harry
Post Number: 24
Registered: 3-2002
| | Posted on Sunday, October 27, 2002 - 12:27 pm: | |
Had the same in my Dino. Light came on at about 3500 rpm, the light was off below and above it. Reason was: worn brushes and worn contact rings on the rotor. What probably happened was that the brushes started to vibrate at a certain speed because the springs did not press the brushes sufficiently against the rings due to the wear on both sides. The vibration is then caused by the lower resonance frequency of the worn spring/brush assembly with less spring load.
You have to replace the voltage regulator (this includes springs and brushes). Also have a look at the contact rings of the rotor. If these are worn, the alternator needs a complete overhaul.
Regards
Harry |
Adam Goldman '86 TR (Icnsltmfg)
Member
Username: Icnsltmfg
Post Number: 426
Registered: 8-2001
| | Posted on Sunday, October 27, 2002 - 10:49 am: | |
I had the same issue on mine with the Alt light coming on. It is the regulators in the Alt. Had the Alt rebuilt and solved the problem. The Alt is at the top, but is in no way an easy thing to get out. It can take a few hrs to slip it through all of the other crap in the engine bay. But since it is a pain, just remove it and rebuild the whole thing and then forget about it. |
Michael N. (Man90tr)
Member
Username: Man90tr
Post Number: 705
Registered: 4-2001
| | Posted on Sunday, October 27, 2002 - 7:05 am: | |
Thanks James and Peter.
I will try your suggestions, look for oil seepage, regulator etc. And yes, the alternator is on the top of the engine, it is easy to get to.
Michael |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 2112
Registered: 12-2000
| | Posted on Sunday, October 27, 2002 - 1:37 am: | |
My first bets are on the regulator too. Cheap fix. Aren't alt's on TR's on top of the engine? |
James Selevan (Jselevan)
Junior Member
Username: Jselevan
Post Number: 182
Registered: 6-2002
| | Posted on Sunday, October 27, 2002 - 12:50 am: | |
Michael - I had a similar symptom with my Dino. When first starting (cold engine), the alternator charged appropriately. As the engine warmed, it would not charge, and in fact, discharged. Long diagnostic story made short, it was oil that, over several years and few miles, had resulted in a failed alternator. Thus, first question: Is there oil seepage ending up on the alternator? Second, is the belt tight? Finally, this sounds more like bad brushes then anything else. Diodes can fail intermittently, but ultimately are all or none. Thus, I suspect brushes or diodes.
The alternator is relatively easy to remove from the TR (relatively is a relative term). I suspect it would be easier to remove then to try and change brushes while in the car. If you bother to remove it, then you can take it to a rebuild shop for testing, and servicing if necessary. I do not believe you have to invoke failure of another component to explain your symptoms (that is, the fuel pump or relay). This appears to be temperature related alternator failure. Belt or brushes or armature or diodes. Either way, alternator likely has to come out.
You might try temporarily replacing the voltage regulator with an off the shelf early American or Japanese variety. There are only 3 connectors, and it will not hurt anything to unplug your regulator and plug in a test regulator (perhaps from an another car you have in the driveway). If the symptoms improve, then you may conclude that the regulator is bad. I did this with the Dino before pulling the alternator.
Hope this helps.
Jim S. |
Michael N. (Man90tr)
Member
Username: Man90tr
Post Number: 703
Registered: 4-2001
| | Posted on Saturday, October 26, 2002 - 8:00 pm: | |
Guys,
I am going to add something else to the mix. The temperarture thing got me thinking and I opened the hood and the cooling hose for the alternator was not in its normal position, it slipped and was pointing mainly at away toward the very, very back of the alternator. Not directly on it like before. Could it be that I am getting a overheated/overtaxed alternator when it gets above 175 degrees or are we back to the slipping belt thing? The alternator is charging fine in that I just started the car and ran it at idle for 20 minutes with lights on etc. and when I hooked up the battery tender it was still showing 90% plus charge. It only got up to 175 but the load on it at idle and driving is so different that I am not too sure if i am recreating the correct scenario. What do you think about the overheating idea?
Thanks,
Michael |
Michael N. (Man90tr)
Member
Username: Man90tr
Post Number: 702
Registered: 4-2001
| | Posted on Saturday, October 26, 2002 - 5:38 pm: | |
Guys,
This question pertains to a 1990 TR.
Here is quick run down of what I just saw. For starters, the car has not been in the shop for the last 4,000 miles (except for oil). Starts up and runs great. I was out driving today and my alternator light came on intermittently (for about 2 seconds or less) betweeen 2000 and 3500 rpms. Fine above 3500 and fine at idle. All lights on, fan blowing and no light at idle. Start driving and every so often (after the car is above 175 degrees) the alternator light is very low dim or flicks on then off. Letting it drop to idle or going above 3500 solves the problem. I am thinking two possible things -- a slipping alternator belt between 2000 and 3500 rpms or a fuel pump/fuel pump relay is going bad. So I decided to check a few things when I got home. Don't think is a bad bridge in the alternator as I just got a new one 5,000 miles ago.
1. Fuse box -- looks clean, all clips as they were 4,000 miles ago.
2. Hooked up battery tester/tender and as normal it showed 75% charge and in 30 minutes it was showing 100% charge. So the battery was not being drained abnormally.
Normal there,-- well while going through this is heard a little whining/almost buzzing sound that lasted about 5 seconds about every 3 minutes or so. This went on for 10 minutes. I have heard this before immediately after shutting down the car but took notice as it was doing this 10 minutes after the car was off. Quit completely after 20 minutes or so.
Question: Do you think I have a slipping belt or a fuel pump going bad and loading up the alternator or shorting it out? I am thinking of first changing the fuel pumps relays to see if that is an issue. Interesting in that it does not happen when car is cold or when at idle siting still -- even in neutral at 3000 -- no light -- only when driving.
Thanks for any help you can give.
Michael
PS: James S. and Steve M. - thanks for your help on the A/C system question your fixes worked and heater is working nicely -- took all of 3 minutes. |
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