Sorry, it's easy to forget things that are obvious to me but not necessarily to anyone else. Connecting +12v to the sensor's screw terminal would read somewhere between zero and 13.5 volts (or thereabouts) ... right up until the extra voltage fried the sensor.
The only time to connect any sensor directly to the battery is to test the sensor's ground. In that case, you'd run a jumper from the battery's negative terminal to the base of the sensor. (Or, a place on the engine close to the sensor.)
1970 Explorer Class A on a 1969 Dodge M300 chassis with 318 cu. in. (split year)
1972 Executive Class A on a Dodge M375 chassis with 413 cu. in.
1973 Explorer Class A on a Dodge RM350 (R4) chassis with 318 engine & tranny from 1970 Explorer Class A
When your taillights act weird, it's usually due to a faulty ground in one of the lights.
Most incandescent taillights use dual element bulbs ... one element is for running lights and the other is for brighter stop and turn signal. The base of the bulb is the common ground for both elements and the two silver-colored buttons on the bottom each provides +12v to it's respective element.
If one of the STT (stop/turn/tail) fixtures has a faulty ground, the current goes through running light circuit to the other fixture to reach a ground.
Fix the ground on the faulty fixture (or both fixtures to be sure) and the problem should go away.
my440 wrote:
Oh the gauge troubles and the voltage regulated sensor behind the cluster panel. Last summers nightmare. Ended up grounding the circuit board directly to the firewall. My failed gauges come to life!
Oh the gauge troubles and the voltage regulated sensor behind the cluster panel. Last summers nightmare. Ended up grounding the circuit board directly to the firewall. My failed gauges come to life!
Just make sure it's the ground copper trace that you connect to the firewall (or another suitable ground source).
If indicator lights share a copper trace, that's probably the ground. (Instrument illumination lights often share two copper traces ... one for ground and the other for +12vdc).
Griff in Fairbanks wrote:
Just make sure it's the ground copper trace that you connect to the firewall (or another suitable ground source).
If indicator lights share a copper trace, that's probably the ground. (Instrument illumination lights often share two copper traces ... one for ground and the other for +12vdc).
my440 wrote:
Oh the gauge troubles and the voltage regulated sensor behind the cluster panel. Last summers nightmare. Ended up grounding the circuit board directly to the firewall. My failed gauges come to life!
Oh the gauge troubles and the voltage regulated sensor behind the cluster panel. Last summers nightmare. Ended up grounding the circuit board directly to the firewall. My failed gauges come to life!
Just make sure it's the ground copper trace that you connect to the firewall (or another suitable ground source).
If indicator lights share a copper trace, that's probably the ground. (Instrument illumination lights often share two copper traces ... one for ground and the other for +12vdc).
Yes thanks Griff!
I never had troubles with the signal lights. More the fuel gauge and temp gauges.
eyeteeth wrote:
Finally got around to digging out the box from the engine temp sensor I put in. NAPA part, TS6178SB.
Finally got around to digging out the box from the engine temp sensor I put in. NAPA part, TS6178SB.
Did some cross-checking ... that is the right sensor for your 440 engine.
I wanted to make sure you hadn't fallen victim to a somewhat common mistake when dealing with older vehicles.
Warning lights ... aka "idiot" lights ... use a simple switch which is closed when the temperature rises to a certain point. Gauges use a sensor that is a variable resistor, which increase and decrease circuit resistance based on the condition it's monitoring.
On vehicles where warning lights and gauges were alternative options, people sometimes use a switch with a gauge-equipped vehicle or vice versa.
The results are usually baffling ... a switch will cause a gauge needle to "peg" right or left, depending on the condition being monitored. For example, an oil pressure switch will cause the oil pressure gauge to show excess oil pressure until oil pressure build up enough to open the switch. (Temperature switches are often thought to be defective in these cases because the switch stays open until engine temperature rises to excessive levels.)
On the other hand, a sensor will cause a warning light to glow with varying intensity due to the variable resistance the sensor creates in the circuit.
This problem arises in some cases when the counterperson doesn't realize the list the computer provides is not simply alternative parts. In other cases, the customer chooses a switch when they needed a sensor because the switches are typically less expensive than the sensors.
In digging through some of the old bookmarks in my web browser, I ran across a link to an article some of the people on this thread may be interested in --
Troublesome amp gauges
The article discusses some of the problems, and potential solutions, found on the electrical systems of older vehicles, especially trucks.
The article is interesting in that it uses older Dodge trucks as an example, versus most articles that discuss Chevy and (occasionally) Ford issues.
It's a well-written, two part article (link to second part at bottom of first part) with lots of pictures. There's also a link to the Autometer site for additional information in the first part of the article.
Griff in Fairbanks wrote:
In digging through some of the old bookmarks in my web browser, I ran across a link to an article some of the people on this thread may be interested in --
Troublesome amp gauges
The article discusses some of the problems, and potential solutions, found on the electrical systems of older vehicles, especially trucks.
In digging through some of the old bookmarks in my web browser, I ran across a link to an article some of the people on this thread may be interested in --
Troublesome amp gauges
The article discusses some of the problems, and potential solutions, found on the electrical systems of older vehicles, especially trucks.
Thanks Griff, I have forwarded that link on to a few friends that either still have, or are interested in these older cars and trucks.
![[emoticon]](http://www.coastresorts.com/sharedcontent/cfb/images/smile.gif "smile")
Downsizing ">
Griff in Fairbanks wrote:
Everybody -
In digging through some of the old bookmarks in my web browser, I ran across a link to an article some of the people on this thread may be interested in --
Troublesome amp gauges
Everybody -
In digging through some of the old bookmarks in my web browser, I ran across a link to an article some of the people on this thread may be interested in --
Troublesome amp gauges
A-a-a-and bookmarked as well. Thanks Griff!