Weird Electrical problem.
Thread Starter
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Weird Electrical problem.
Has anybody ever seen a problem like this:
Everything seems Ok until I turn the lights on. At this point the water temp gauge goes off the top of the scale & the gauge light doesn't come on. If I dim the dash lights with the dimmer switch, then the temperature gauge drops as the lights are dimmed (it's great - I can set any running temperature that I want, no fans or expensive alloy radiators for me, just adjust the temperature with the dimmer switch :cool: ). I'm not too worried about this as its obviosly a bad connection behind the console BUT when the lights are on the battery warning light glows very slightly. I thought this could be light from the gauge illumination bulbs but the starter seems to be turning the engine over slower than normal.
Is there any effect that a bad console connection could have on the charging circuit (the battery voltage gauge reads as normal)?
TIA
paul
:smash:
Electrics
Everything seems Ok until I turn the lights on. At this point the water temp gauge goes off the top of the scale & the gauge light doesn't come on. If I dim the dash lights with the dimmer switch, then the temperature gauge drops as the lights are dimmed (it's great - I can set any running temperature that I want, no fans or expensive alloy radiators for me, just adjust the temperature with the dimmer switch :cool: ). I'm not too worried about this as its obviosly a bad connection behind the console BUT when the lights are on the battery warning light glows very slightly. I thought this could be light from the gauge illumination bulbs but the starter seems to be turning the engine over slower than normal.
Is there any effect that a bad console connection could have on the charging circuit (the battery voltage gauge reads as normal)?
TIA
paul
:smash:
Electrics
Instructor
Joined: Feb 2001
Posts: 122
Likes: 0
From: Greensboro NC
Re: Weird Electrical problem. (UKPaul)
That is weird. Have you had any recent electrical work done or wires loose. One possibility is your dash light control going to temp gauge.
Does the gauge work properly with light off.
Might also be a loose or bad ground to dash. :crazy:
Does the gauge work properly with light off.
Might also be a loose or bad ground to dash. :crazy:
Thread Starter
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Re: Weird Electrical problem. (curly)
Thanks for the reply. I haven't had any work done. Everything was OK until I hit a pothole in the road 2 weeks ago (the roads here can be abysmal). When that happend the temp gauge went off the scale, so going into Bubba mode, I aimed at the next pothole I saw & after the bump the gauge went back to normal. All was OK til 2 nights ago when I noticed that it was reading max & the battery warning light was glowing dimly. The gauge seems OK with the lights off. I'm usually OK with electrickery but this one seems really odd - why should the temp gauge affect the battery warning light/charging rate? :rolleyes: I was wondering if there is a relay or something involved betweed the alternator & battery?
Paul
Paul
Le Mans Master
Joined: Aug 2000
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From: Semper ubi, sub ubi
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Re: Weird Electrical problem. (UKPaul)
Paul,
Apparently the jar from the pothole caused either a wire going to you instrument lighting to come loose and short to the temp gauge. If that isn't the case then I assume that there is a short in the circuit board to you gauges.
Pull the gauges and the chances are pretty good that the problem will be easily seen. I don't know how difficult pulling the center cluster, but it has to be easier than the 68-76 models.
Apparently the jar from the pothole caused either a wire going to you instrument lighting to come loose and short to the temp gauge. If that isn't the case then I assume that there is a short in the circuit board to you gauges.
Pull the gauges and the chances are pretty good that the problem will be easily seen. I don't know how difficult pulling the center cluster, but it has to be easier than the 68-76 models.
Advanced
Joined: Jun 2001
Posts: 67
Likes: 0
From: Idaho Falls, ID ID
Re: Weird Electrical problem. (UKPaul)
I actually have almost the same exact problem with my 1980 Corvette. When I turn on the lights the Temp gauge pegs out as high as it can go. It is getting it's hood painted right now or I would go try dimming the switch to see if I also have an adjustable temp. Let me know when you find something out.
Suprdave
Suprdave
Safety Car
Joined: Jul 2001
Posts: 3,921
Likes: 2
From: York PA
Re: Weird Electrical problem. (UKPaul)
The connection to the back of guage consule is a really cheesy setup, it is very easy to get circuits that are connected together. I attempted to glue the contacts back to the plastic circuit board, but they pulled back off the first time I disconnected the connector. 
Best I could do is make sure that when you plug the connector back in, make sure the terminals are straight and separated as much as possible.
Best I could do is make sure that when you plug the connector back in, make sure the terminals are straight and separated as much as possible.
Burning Brakes
Joined: Dec 2000
Posts: 1,183
Likes: 2
From: Des Moines Iowa
Re: Weird Electrical problem. (UKPaul)
Quote: "The connection to the back of guage consule is a really cheesy setup, it is very easy to get circuits that are connected together."
I agree with this statement. After a new sending unit, and trying out a new gauge, I found out that my malfunctioning oil pressure indicator problem was simply this connection to the gauge cluster. I found I could make the gauge work or not work, simply by wiggling the connection, which I could reach with the gauge cluster bolts removed and having pulled it rear word somewhat.
I too straightened out some of these connectors, cleaned and polished them with some very fine emery cloth, and re-installed, with no problems since then.
I agree with this statement. After a new sending unit, and trying out a new gauge, I found out that my malfunctioning oil pressure indicator problem was simply this connection to the gauge cluster. I found I could make the gauge work or not work, simply by wiggling the connection, which I could reach with the gauge cluster bolts removed and having pulled it rear word somewhat.
I too straightened out some of these connectors, cleaned and polished them with some very fine emery cloth, and re-installed, with no problems since then.
Thread Starter
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Re: Weird Electrical problem. (john's '81 mouse)
Thanks for the help, people. So,it's out with the gauge cluster then - & I'd put money on that turning into a nightmare job! I'll do it on the weekend & let you know what I find.
Cheers
paul
Cheers
paul
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Melting Slicks
Joined: May 2000
Posts: 2,305
Likes: 5
From: Orlando,Fl,USA
Re: Weird Electrical problem. (UKPaul)
I have a similar prob with the 77. The volt gauge is the one that acts weird. With the lights on it is okay as long as the dash lights are turned off. As I increase illumination the volts drop down to the lwr end (8). I notice that the light behind the volt gauge isn't working as well as the others and if I tap it hard it will illuminate and the volt gauge corrects? It happened on some pot holes also. I hav'nt tackled the dash job yet.
Burning Brakes
Joined: Jul 2000
Posts: 1,045
Likes: 3
Re: Weird Electrical problem. (dogboy)
I just had the same problem with my 79. If you look at the connector on the back of the console you will see that the water temp and light wires are next to each other. Upper right and second from the top when looking at the console on a bench. A little nathpa to clean and a drop of crazy glue under the copper contact.
I had the same problem with the speedo/tach cluster. The tach and ground are next to each other. Guess what happens when the groung and tach touch, a no start problem.
I keep learning things that I never wanted to know. But thats the fun of working on your car instead of paying somebody to do it.
I had the same problem with the speedo/tach cluster. The tach and ground are next to each other. Guess what happens when the groung and tach touch, a no start problem.
I keep learning things that I never wanted to know. But thats the fun of working on your car instead of paying somebody to do it.
Tech Contributor
Joined: Aug 1999
Posts: 14,384
Likes: 6,411
From: At my Bar drinking and wrenching in Lafayette Colorado
Re: Weird Electrical problem. (UKPaul)
You have one of two things going: Either your dash light wire is touching the temp wire at the connector, or you have a bad ground. A bad ground for the dash printed curcuit board (usually caused from a crack or a break in one of the ground circuits on the board) will cause the dash lights to find the next available ground - it goes through the gauge. This pegs the gauge out. If you do not find a problem at the connector, and the problem persists after cleaning up the connector (Radio Shack has really good Contact Cleaner in a spray can - it's great stuff and works really well), you'll need to get the dash out of the car and carefully examine the printed circuit. Once you find the cracked circuit, you can solder it back together. Very common problem.
Thread Starter
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Re: Weird Electrical problem. (lars)
Hi,
Hope you all had a good weekend. Well I removed the centre console (no easy job - Bubba had glued it & all the switches together!) & was having problems getting the instrument console out. Took out the glove box (6 screws) & got my hand behind the instrument cluster. The electrical connector wasn't quite fully home - just pushed it fully in & my temperature gauge now works OK. Thanks for the help.
Now just got to find out why I'm now doing 3000rpm @ 70mph when 2 weeks ago it was doing 2850rpm @ 70mph :confused:
Paul
Hope you all had a good weekend. Well I removed the centre console (no easy job - Bubba had glued it & all the switches together!) & was having problems getting the instrument console out. Took out the glove box (6 screws) & got my hand behind the instrument cluster. The electrical connector wasn't quite fully home - just pushed it fully in & my temperature gauge now works OK. Thanks for the help.
Now just got to find out why I'm now doing 3000rpm @ 70mph when 2 weeks ago it was doing 2850rpm @ 70mph :confused:
Paul
Thread Starter
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Re: Weird Electrical problem. (UKPaul)
For info, if anybody has the same type of problem:
Tried to start the car last night & the solenoid frantically started clicking, then all electrics went dead. Nothing. A bit later it all came back, but trying to start the car resulted in the same thing. Found that the nut holding the battery cable and live wires on the solenoid was very slightly loose. After tightening it everything worked AND the battery warning light no longer glows when the lights are on (so it wasn't "light pollution" after all). Maybe some of the strange electrical hiccups won't happen anymore.
Tried to start the car last night & the solenoid frantically started clicking, then all electrics went dead. Nothing. A bit later it all came back, but trying to start the car resulted in the same thing. Found that the nut holding the battery cable and live wires on the solenoid was very slightly loose. After tightening it everything worked AND the battery warning light no longer glows when the lights are on (so it wasn't "light pollution" after all). Maybe some of the strange electrical hiccups won't happen anymore.
