Electrical - "Mostly" ok - Pontiac GTO Forum
User Tag List

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 49 (permalink) Old 08-17-2011, 07:52 PM Thread Starter
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
Electrical - "Mostly" ok

Yee ha! Well, I fired it up on it's own electrical system for the first time in what... more than 20 years?

"Almost" everything works. Oil pressure, tach - check.

Temperature guage? Not so much - also not sure eveything's 100% with the charging system.

Temperature gauge: Weird. Goes to below 100 degrees (limit of travel on the needle) and stays there -- until I let the motor idle down, then it creeps down towards the middle of the scale and bounces. It's acting like a tach, sort of - it moves "upward" (colder is "up" on the scale) as soon as I take it off idle and that's where it stays. I know the motor's warming up (duh) and it had to get close to 180 because the cooling fans cycled on and off (yay). I just tried completely disconnecting the lead from the sending unit, and it behaved exactly the same way. Weird.

Another weird thing. GENerator light glows faintly. When I first turn on the ignition, it's almost not on. Seems to gradually increase in intensity over the span of 20-30 seconds, engine on or off, whenever the ignition is on. Battery's new, and I keep it on a battery minder. Voltage is where it ought to be, 12.8 engine off - 14.3 to 14.8 engine running, and I see a dip when I turn on the heater blower on high, then it comes back. Voltage regulator (external) is brand new, got a good one (Echlin) from Napa. I did take the alternator in a few months back and had it tested. It showed to be good. Ground straps from block to body and from body to frame are in place and brand new.

BRAKE warning light comes on and stays on even if I press the pedal, but I'm mostly hoping that's just because I haven't finished bleeding the brake system yet so I'm not concerned - yet.

Headlight relay for ignition works great Thanks again Brian.

Does anyone have solutions to these mysteries?

Thanks,
Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
Sponsored Links
Advertisement
 
post #2 of 49 (permalink) Old 08-17-2011, 08:08 PM
 
Instg8ter's Avatar
 
Join Date: Sep 2010
Location: Near Detroit
Posts: 3,931
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 23 Post(s)
happy to pass it along Bear, i thought it was a pretty slick work around too, saved me the confusion of having to track everything back to the ignition and fuse block (like i am going through now with my brake/turn signals). my brake light stays on too and i am fully bled (just another electrical mystery to track down in time. I too was amazed when i put power to mine that everything lit right up and worked i have found a few splices in the trunk so i think the brake light turn signal thing is not new, next step fuse block, then i may just run new wires rather than tear my interior apart to check the ribbon. Can't wait to see that interior in your car so you can take her for a little spin....you must be getting antsy...i know i was did the whole interior in a 3 day weekend.....
Instg8ter is offline  
post #3 of 49 (permalink) Old 08-17-2011, 08:23 PM Thread Starter
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
# 1000

Well how about 'dat? I think this here right here is my 1000th post on the forum.

I guess it's appropriate for it to be associated with another milestone on my car, even if everything isn't exactly perfect yet.

I went out and shot a video of how things are looking, hopefully someone will be able to recognize the symptoms and point me towards some solutions.

Here's the link to the video:



Thanks guys,

Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
 
post #4 of 49 (permalink) Old 08-17-2011, 08:51 PM
64-67 Expert
 
geeteeohguy's Avatar
 
Join Date: Feb 2008
Location: Fresno, California
Posts: 8,488
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 102 Post(s)
Bear, glad you're making progress. The dim light with okay charging could be a bad diode in the alternator. I've had it happen. The brake light on all the time could also be caused by this as well. It could also be that your proportioning valve (metering valve) needs to be centered. I think you have a custom system, so I'm not sure if your valve has a button on it or you need to jump thru some hoops in a certain order (bleeding the valve/system) to get the valve to re-center and turn off the light. I'd swap in a different alternator first....or, knowing you, take the old one apart and inspect it really close. Gauges: factory gauges not in use for decades can do strang things when put back into service. I'd personally drive the car a while and see if it settles down. If you don't want to pull the dash or pod later (and want to do it now),Pete Serio is 'the man" when it comes to this stuff. He helped me a lot getting my '65 rally gauges back into shape. As you know, he's on the "other" forum. You're getting close...can't wait to see video of it on the road!!!
geeteeohguy is offline  
post #5 of 49 (permalink) Old 08-17-2011, 09:07 PM
 
Join Date: Oct 2007
Location: Long Island NY
Posts: 4,702
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Garage
just one thing to add don't put teflon tape on the water sender. It can cause a bad ground and make the gauge act funny. The engine sounds sweet....Eric



Eric Animal is offline  
post #6 of 49 (permalink) Old 08-17-2011, 09:45 PM Thread Starter
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
Quote:
Originally Posted by Eric Animal View Post
just one thing to add don't put teflon tape on the water sender. It can cause a bad ground and make the gauge act funny. The engine sounds sweet....Eric
Oh man! I thought sure that was it because I did indeed use teflon tape. I just checked the housing with my meter though, and it shows zero ohms resistance from the sender housing to ground. If that was it that'd explain why it acts the same wether or not it's connected tho. That part, and also the fact that the reading fluctuates with RPM, is bothering me because I can't quite reason out what woiuld make it do that.

If I understand right, these gauges are basically ammeters, and they work by measuring current flow. The magic is in the sending unit in that it provides a resistance path to ground that varies with either temperature or pressure. Do I have that right? (In that case I guess itd' actually more accurate to call them "receiving" units.. except in physics I learned that dc current actually flows from negative to positive so "sending" would be correct - making my head hurt here )

Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
post #7 of 49 (permalink) Old 08-17-2011, 09:49 PM Thread Starter
Super Moderator
 
BearGFR's Avatar
 
Join Date: Aug 2008
Location: Springtown, TX
Posts: 5,737
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 122 Post(s)
Garage
Quote:
Originally Posted by geeteeohguy View Post
If you don't want to pull the dash or pod later (and want to do it now),Pete Serio is 'the man" when it comes to this stuff. He helped me a lot getting my '65 rally gauges back into shape. As you know, he's on the "other" forum.
I just got it in so I'm not excited about pulling it, but if it has to come back out this would be the time to do it.

I don't know Pete, but it sure sounds like I need to! I assume you're talking about PY? Does he go by Pete over there?

Thanks bro...

Bear

BearGFR
Springtown, TEXAS
BearGFR is offline  
post #8 of 49 (permalink) Old 08-18-2011, 08:46 AM
 
66tempestGT's Avatar
 
Join Date: Nov 2009
Location: montevallo,al
Posts: 1,373
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
is the cluster grounded good to the body? if the guage acts funny when its not connected then its feeding back from something else. could be causing some of the other problems too.


Shane Doss

66 tempest
64 el camino
02 mullis dragster
66tempestGT is offline  
post #9 of 49 (permalink) Old 08-18-2011, 08:49 AM
 
Join Date: Oct 2007
Location: Long Island NY
Posts: 4,702
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 1 Post(s)
Garage
He goes by Pete Serio on PY, his business address is http://www.precisionpontiac.net. A bad ground or old "leaky" printed circuit board is notorious for causing weird gauge readings.....



Eric Animal is offline  
post #10 of 49 (permalink) Old 08-18-2011, 09:12 AM
64-67 Expert
 
geeteeohguy's Avatar
 
Join Date: Feb 2008
Location: Fresno, California
Posts: 8,488
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 102 Post(s)
Good point on the cluster ground, 66. Real good point. Bear, yes, you know how the gauges work--actually, as usual,you explained it really well! Just recieving units working on resistors or sometimes thermistors. For a gauge to fluctuate with rpm, that means the resistance or voltage is changing in the circuit as the rpm changes, and doing it rapidly. Shouldn't be. The spring in the gauge could be bad, or it could be a ground or a charging system issue(voltage spiking),or a resistance issue/short in a circuit of sender. Talk to Pete. He may know of a'pattern failure with these gauges and point you right to it!
geeteeohguy is offline  
Sponsored Links
Advertisement
 
Reply

  Pontiac GTO Forum > The 1964-1974 Pontiac Tempest, Lemans & GTO > 1964-1974 Tempest, LeMans & GTO Projects, Barn Finds & Restoration Discussions

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Pontiac GTO Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
K&N aftermarket cai keeps thowing "IAT" codes wtf gmForever82 Intake and Exhaust Discussions 2 08-16-2011 07:25 AM
PFYC's Low Price Guarantee "Double Credit" Challenge PFYC 2004-2006 GTO General Discussion 0 05-06-2010 09:32 AM
Another "what is this?" electrical thread. firecatsrt 1964-1974 Tempest, LeMans & GTO Technical and Electrical Wiring 9 06-24-2009 10:10 AM
Spare "tire"..better check it. "my lucky day" JWCACE Wheels and tires 0 05-17-2006 09:32 AM
Business Opportunity - Still Looking for "Assistant" AMSOIL Dealer Forum Vendor Subdriver The Lounge 0 03-29-2005 08:40 AM

Posting Rules  
You may post new threads
You may 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 Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome