| Author |
Message |
S. Long (Sml)
New member
Username: Sml
Post Number: 39
Registered: 2-2001
| | Posted on Monday, March 11, 2002 - 4:52 pm: | |
Absolutely fabulous response to my problem! Thank you all very much (especially to 1975GT4Don and Ricrain). As soon as I re-visit my 328 in late March (garaged on Cape Cod...I live in NYC) I will put all suggestions to work. I have great confidence she will be back to normal thanks to you all. Cheers. SML |
BretM (Bretm)
Intermediate Member
Username: Bretm
Post Number: 1948
Registered: 2-2001
| | Posted on Monday, March 11, 2002 - 1:52 pm: | |
One time at night I hit a bump and my left headlight just decided to go to being half open (or half closed depending on how you look at it). I turned off the lights and put them back on and it was alright. Then I hit a bump again and it went to half closed again, no matter how many times I opened and closed them it just wouldn't open past there. The next day I was checking it out, readjusted the length of that arm so the light was nice and flush with the body when closed, it worked fine again and I've never had any problems since. Gotta love Ferrari's electrical systems, who needs lights anyway. |
1975GT4Don (1975gt4don)
New member
Username: 1975gt4don
Post Number: 28
Registered: 1-2002
| | Posted on Monday, March 11, 2002 - 1:23 pm: | |
S. Long, your problem is a floating ground. you need to remove the ground wire from each headlight motor and lightly sandpaper an area near the wire, preferably a screw or a bolt attached to the frame of the car. I had the same problems for many years, after doing this, the problem never appeared again after 10 years. Ferrari electrical grounds are poor. Most chassis connections for ground were connected over undercoating or rusted bolts. Brilliant. |
William Badurski (Billb)
New member
Username: Billb
Post Number: 28
Registered: 6-2001
| | Posted on Sunday, March 10, 2002 - 4:42 pm: | |
Ric,
Just as you suggested, I found one defective diode on the opposite headlamp (the one that doesn't "wink")! No limit switches either. Since I'm about to start the engine after doing a year-long overhaul, I put off pulling the headlamp motor for a couple of days, then look for a diode. Thanks a bunch. You answered a question that has perplexed many of the technical guys I've talked to. |
'75 308 GT4 (Peter)
Intermediate Member
Username: Peter
Post Number: 1661
Registered: 12-2000
| | Posted on Sunday, March 10, 2002 - 3:49 pm: | |
Steve, my ('75) GT4 does not have limit microswitches. |
William Badurski (Billb)
New member
Username: Billb
Post Number: 27
Registered: 6-2001
| | Posted on Sunday, March 10, 2002 - 11:14 am: | |
Ric & Steve,
Thanks so much for taking the time to reply, and for the detailed troubleshooting guide. I'll give this a try. Great website for DIYers! |
Ric Rainbolt (Ricrain)
New member
Username: Ricrain
Post Number: 23
Registered: 2-2002
| | Posted on Sunday, March 10, 2002 - 10:27 am: | |
"When the lights are turned on, the right one comes up, goes down, and comes up a second time to stay"
The problem with the Daytona is that one or more diodes is burned out in the motor. Each motor has two diodes in it. Typically, the diode that's burned out is in the other motor that the one that's acting up.
What follows is a procedure that I wrote in '97 for checking for this problem. It may also be useful for finding the original poster's problem.
-----------------------------------------------------------------------
Stan is referring to a problem that occurs when one or more diodes (rectifiers) in the headlamp lifter motors fails. This can cause problems such as "winking" headlamps (one side or both), continuously running motors (up and down), or the lack of synchronization of the left and right motors. Loose or dirty connectors can also cause intermittent running or "cycling", as well. Non-functioning (dead) lifters is either the motor, wiring or the associated relay.
The good news is, you can check the diodes in the headlamp lifter motor without removing the motors from the car. You'll need a multi-meter (VOM) that is capable of checking diodes (preferred) or one that has an low resistance Ohms range. Also needed are some screwdrivers and possibly end wrenches (10mm) and a low-wattage soldering iron.
This procedure is for 308's, specifically my '81 308 2-valve. Other models and/or years may vary, but I think its the same all the way through the 328 model. GT/4's and 246's may be similar.
1) Disconnect the battery ground strap.
2) The headlamp motors connectors (both sides) should be disconnected. You probably will need to remove the grill (308's) or cover (328's) above the headlamp mechanisms to accomplish this, or, if you're flexible and nimble, you may be able to reach it with just the front bonnet up.
3) Use the hand crank knob on top of the motor to move the headlamp to about the halfway point (i.e. 1/2 up, 1/2 down). No precision is needed, just somewhere in between.
4) Now use the VOM to check the diodes by measuring the conductivity on the BLACK and GREY terminals. Measure with the VOM and then reverse the VOM leads and measure again.
If you have a VOM with a diode check feature, in one direction you'll get infinity (no reading) and in the other you'll get a low value (usually less than 1.00 V).
If you're using a VOM in Ohms mode, select a low scale range (1-3K ohms). In one direction you should get a low reading and in the other a fairly high or infinite reading.
5) Now check the other diode by measuring, as in step 4, with the BLACK and GREEN+BLACK wires. Note that at this point, both diodes share the BLACK wire.
6) If all is well, you should have made four measurements. Two will show a low value and two a high (or infinite) value. If any pair shows low values in both directions, the diode is shorted out and needs to be replaced. If any pair shows high values in both directions, the diode is "blown" and needs to be replaced.
7) If either diode is bad, you'll need to remove the motor from the car. This can be done by removing the drive lever nut and the drive lever and then the three bolts that hold the motor to the headlamp lifter assembly.
8) Peel back the rubber covers on the motor. This can be tough, but it can be done. Only the lower cover needs to be removed.
9) On the lower part of the mechanism, below the motor on the gear housing, you'll find a pair of diode rectifiers (small cylinders, usually black with a white or silver stripe at one end, with two metal leads coming out). Using a low-wattage soldering iron (designed for electronics, not woodburning) and remove the offending diode. Make sure to note the orientation of the diode before removing it. If you don't know which one is which, measure the diodes again with the VOM, this time directly on the diodes leads.
10) Take the dead rectifier to your local friendly electronics parts store (Radio Shack or equivalent) and find a similar sized unit from their stock. Exact specs are not really critical as all the part is only used for is to rectify a signal to a relay. Find a rectifier with at least a 1 Amp rating and a minimum of 50V. A "1N4001" is a good choice.
11) Put the good rectifier on the motor and perform steps 4-6 again. If all is well, reseal and return the lifter motor to the car.
12) Reconnect the connectors and the battery ground strap and test. Be careful when you reconnect the ground strap, since the half open headlamps will most likely cycle back to the resting position... don't be in the way when this happens, the car could get scratched or it could bite off your fingertips.
NOTE: Measure both headlamp lifter motor's diodes. Sometimes, a diode failure in one motor can cause the opposite headlamp to act up (no really).
|
Steve Magnusson (91tr)
Member
Username: 91tr
Post Number: 584
Registered: 1-2001
| | Posted on Sunday, March 10, 2002 - 9:52 am: | |
Don't all the headlamp lifting mechanisms have a DT microswitch somewhere which is activated by a rotating cam to signal both the up and down positions? If the stalk switch assembly and the various relays are OK, I'd suspect that the microswitch(es) have a problem -- but the bottom line is that you need a schematic and a multimeter unless you just want to guess IMO. |
William Badurski (Billb)
New member
Username: Billb
Post Number: 26
Registered: 6-2001
| | Posted on Sunday, March 10, 2002 - 6:41 am: | |
If anyone out there knows the answer, I certainly would appreciate it. I have a similar problem with my Daytona. When the lights are turned on, the right one comes up, goes down, and comes up a second time to stay. I have changed the steering column mounted headlamp switch, and swapped the relays from side to side with no change in results. The right lamp still does the same thing. It must be in the lamp assembly or motor. |
Richelson (Richelson)
Member
Username: Richelson
Post Number: 545
Registered: 12-2001
| | Posted on Sunday, March 10, 2002 - 6:34 am: | |
I would check the relay. I think you could always swap relays with the other headlamp relay and see if it solves your problem. |
stacy o'blenes (Stacy)
New member
Username: Stacy
Post Number: 35
Registered: 8-2001
| | Posted on Sunday, March 10, 2002 - 1:07 am: | |
Do a search for diode in the tech Q&A section. There was a thread awhile back on this subgect re 308's My car has one headlight that goes down, comes back up and then goes down again when you turn the lights off. The guy who checked the car for me before I bought told me that these problems are caused by diodes on the motors that go bad. I am not sure if this applies to 328's.
Good luck
|
Brian stewart (Eurocardoc)
Junior Member
Username: Eurocardoc
Post Number: 212
Registered: 11-2001
| | Posted on Saturday, March 09, 2002 - 8:01 pm: | |
I am not near a 328 or my shop at the moment but isn't there two relays for the headlamp lift? Look on the fusebox cover panel. On 308 when the light switch itself begins to fail (unobtanium now unfortunately) the light pods will go up and down without stopping. |
Adam Goldman '86 TR (Icnsltmfg)
Member
Username: Icnsltmfg
Post Number: 265
Registered: 8-2001
| | Posted on Saturday, March 09, 2002 - 7:22 pm: | |
I do not have a 328, but I would assume there must be alimit switch so it knows when it is up or down....Could be a bad switch, or connection to that switch. |
S. Long (Sml)
New member
Username: Sml
Post Number: 38
Registered: 2-2001
| | Posted on Saturday, March 09, 2002 - 6:47 pm: | |
tried all suggestions but nothing works. I looked at he opposite lite housing and noticed that the motor stops at the highest point and closes at lowest piont. I also noticed that it is possible to adjust the rotation on the swing arm (open/close position) but can not stop it from continuing to rotate around making the light continuously open/close. Any suggestions as to what is happening and/or how to fix the problem? '89 328 gts. many thanks. |
David Harris (Dakharris)
Junior Member
Username: Dakharris
Post Number: 125
Registered: 6-2001
| | Posted on Monday, March 04, 2002 - 6:15 pm: | |
Try wiggling the wire loom and bend it in a different direction. Unplug and plug in the connections. Also check to see if it is adjusted to the proper open and close positions. You can eyeball the settings. |
S. Long (Sml)
New member
Username: Sml
Post Number: 36
Registered: 2-2001
| | Posted on Monday, March 04, 2002 - 4:30 pm: | |
when i turn "on" the headlamps ('89 328 GTS) the left light lid opens and closes without stopping unless external pressure (ie: my hand) is applied. Any suggestions as to why this is happening? My guess...wire corrosion causing a short. But couldn't find any corrosion. Any suggestions? |