wires are metal ...

<huge snip>

Went and found a manual for same or similar online (64mb):

formatting link
It seems that the fuse for the radio may also do a few other things:

Idle Stop Solenoid, Aux. Battery, Radio, Time Delay Relay, Emission Control Solenoid, Transmission Downshift (M40) ..... 15 amp

This is from page 1331 in the manual mentioned above. Maybe it will make more sense to Snag...

Reply to
Leon Fisk
Loading thread data ...
<snip>

Don't know Jim, just stuff I saw changing in the way things were being done via schematics. I posted an image here of the power output section, schematic for an old RS Cassette player in my truck:

formatting link
Note the voltage on the output IC's headed directly to the speakers...

Reply to
Leon Fisk

I'm a big fan of monitoring current as well as voltage when hunting for a problem, and I built analog and digital ammeters into my home solar system.

formatting link
does read DC current, but it drifts and is noisy on a scope.

Reply to
Jim Wilkins
<snip>

I hear yah :)

I originally bought my Fluke 87 to try figuring out an intermittent problem at a rural tower site. Base station was occasionally blow a fuse. The 87 has MIN/MAX capture capabilities. It didn't work out though, really need something with more inputs and logging abilities...

So I started moving an added inline fused lead around, see if it blew or not. Turned out being a bad high voltage transformer, very expensive and not something any of us had ever seen go bad before.

This was many years ago. The 87 hadn't been out long then. Nowadays there are some pretty nice looking meters for not so much money that would be great for stuff like that.

Reply to
Leon Fisk

I use TP4000ZCs to datalog slowly changing voltages, temperatures and currents on a laptop.

formatting link
The data outputs are optically isolated so the meters commons won't short different voltages together. The TP4000ZC takes primary or rechargeable AA cells and the laptop can operate at a remote site from a jumpstarter battery and inverter or auto-air adapter. The older, thicker laptops I use have PC Card and ExpressCard slots that take extra COM or USB port expanders.

The setup is clumsier and slower than a good industrial datalogger but much cheaper, and has the laptop's user interface and huge storage capacity and the versatility of all the meters' input ranges.

Reply to
Jim Wilkins

About the worst I ever ran across was a 1983 Dodge Aries where the wiring harness for door locks and power windows complete with cloth tape protected, spot welded branch connections, was routed under the floor mat insulation/padding under the drivers feet. Were else in the car could you find a greater quantity of chemical laden water during cold weather in the Great White North!

Reply to
Gerry

ANd the tranny WAS just changed - I'd definitely be looking at downshift wire - - -

Reply to
Clare Snyder

Don't start looking at modern cars and trucks then. Wiring under the carpet is nothing these days. Many locate the primary control modules like the BCM or ECM under the carpets or even in pockets under the floors. Many of these are domestics and the high dollar imports. Mercedes locates various modules under the carpet and even in the channels between the door and floor. I've opened up BMWs where the ECMs are in a case below the floor that were full of water!

Reply to
Steve W.
<snip>

Most every time you post a link to something like that I go have a look-see :)

I think my Fluke 87 cost around $325 in the early 90's. I'll bet the two meters would swap back and forth between their rubber armor seamlessly...

I bought several used DVM's last winter than need some love. A B&K 2810 for parts or repair. I fried my 2810 around last December doing something really stupid and I miss it. Also a Fluke 37 which looks like an early 87 series functionally and a Fluke 8010A which I think needs some serious switch cleaning/repair. Maybe I'll get the urge to fix them this season ;-)

Reply to
Leon Fisk

Maybe, the M40 is the THM400 transmission. Those trucks also used the

700R4 and THM350 which wouldn't apply then. If he does have the M40 then he could check it by turning on the key and depressing the gas pedal to the floor. See if it blows a good fuse. There was a procedure for checking the downshift function in that manual...
Reply to
Leon Fisk

  This truck has a 700R4 ... I'll be pulling that fuse block tomorrow to see what's also hooked to that fuse - I'll also be checking those diagrams that Leon posted the links to . Lots of good leads from y'all , I've been to Memphis to take the grandson home from his 2 week visit .
Reply to
Terry Coombs

Good plan, but... After cutting the wire a few inches out of the fuse block, I'd drive a few miles to make sure it doesn't blow the fuse. There's got to be some version of Murphy's Law that says the short will be in the wire you didn't check separately.

Also, a multimeter with a continuity beeper could be a friend here. Hook it up between the supply wire and ground (fuse pulled first) and then wiggle all the wires. When it beeps, you've found your short.

Reply to
rangerssuck

Is the radio the only thing that's on that fuse? I'd run a new wire with an inline fuse from the radio to the battery and see what happens. Are you sure the problem isn't in the radio?

Reply to
gray_wolf

As noted on another group the trasnmission torqueconverter lockup runs off that fuse too. Since the transmission swap was a "shade tree job" the chances of it being related to the transmission replacement are roughly 1000% - - - - - - - When the controls call for TC lockup the fuse blows.

Reply to
Clare Snyder

On my Honda the TC lockup occurs only in the highest gears, at constant speed on a level road, an easy condition to test with the radio unplugged. I can tell when it's locked because the speedo and tach needles move together.

Reply to
Jim Wilkins

  And Clare found it , and I just a few minutes ago verified that this is (with 99.99% assurance) the problem . I'll get under there tomorrow and find where it's grounding , but I did a road test with speeds high enough to call for lockup with that wire unplugged and the fuse is still intact . The internet truly is an information highway . I would never have known that device was powered by the same fuse as the radio .
Reply to
Terry Coombs

There are times when having a complete wiring diagram can be a big help. :-) What's on the load side of the TC lockup output A solenoid or some such? shorted?

Reply to
gray_wolf

  Well , so far I have traced the brown/white wire across the steering column to where it plugs in to a device - probably a relay of some kind

- mounted on the steering column . It comes out on a blue which goes thru the firewall alone then to a small bundle that heads towards the tranny . My guess is that the blue wire plugs (or is supposed to) into the lockup solenoid , and is either unhooked or damaged and grounded . I'll find out in the morning . My wife has resigned herself to me keeping this truck , but that don't mean she's happy about it . I've also got a set of 3.42:1 gears for the rear axle , the 2.73's just don't get it up here in the "mountains" - I grew up in the "real" mountains , northern Utahaha at the foot of the Wasatch Front .

Reply to
Terry Coombs

POSSIBLY a shorted solenoid valve - but most likely a pinched wire from the transmission changeover. - possibly even just the wires crossed sothe power goes directly to ground instead of through the solenoid coil. You'd be surprised at what a shade tree mechanic is capable of screwing up. (and I've seen some real "shade tree" mechanics working in real shops too - - - - - )

Had one guy collect a paycheck from me for a couple months before I had to let him go. Saying he "worked for me" would have been stretching the truth. I'd bend over and put the knuckle of my thumb against the ground and say "that's Dave". So lazy he was always standing around with his thumb uph his arse - and so dumb he didn't know his arse from a hole inthe ground. It took longer to clear up his comebacks than the length of time he "worked for" me.

Reply to
Clare Snyder

I know the feeling. In a past life I was the service manager of a large company. good help was hard to find and I was well aware of some peoples limitations. Lack of education? How do you educate a brick?

Reply to
gray_wolf

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.