Repairing International Instrument Cluster

warewolff · 10-13-2016, 07:05 PM

Hi all,

Last time I took the bus out for a drive I noticed that the cluster was kicking in and out intermittently. Looks like most of the gauges are affected. I popped it out and grabbed my soldering kit to go through the board more carefully and clean it up, but I'm having trouble getting the main board itself out.

Photos...

Front of the instrument cluster after removing the plexiglass:

Rear of instrument cluster -- left and right boards have already been removed:

Close ups of the main board. Notice that I've already removed all the screws.

I peeled back some of the panels on the front and there is no access to the back of the board. Can anyone point me in the right direction? I've gently pried the board up with a screw driver but there is a lot of resistance and I'd prefer not to break it. How do I get this thing out so I can properly service it?

cadillackid · 10-13-2016, 07:12 PM

when I repaired the one for DEV i had to pop the needles off of the gauges to gert the board out.. that one is also a 1991.. I have not done it yet to the new bus.. it is somethibng I'll tackle when I am back in ohio...

on the DEV the needles just popped off and pressed back on.. masybe there is a better way .. i also remembered where the needles were as on that 1991 panel the needles could be installed in any orientation so I was careful to put them back the way they belong.
-Christopher

warewolff · 10-13-2016, 08:21 PM

Quote:

Originally Posted by cadillackid

when I repaired the one for DEV i had to pop the needles off of the gauges to gert the board out.. that one is also a 1991.. I have not done it yet to the new bus.. it is somethibng I'll tackle when I am back in ohio...

on the DEV the needles just popped off and pressed back on.. masybe there is a better way .. i also remembered where the needles were as on that 1991 panel the needles could be installed in any orientation so I was careful to put them back the way they belong.
-Christopher

I just gave it another go after reading your comment and made a bit more progress on disassembly. Turns out you DON'T need to remove the needles (how did you put them back in the 'right' position again?). I hope I didn't foul anything up in the process..

There are 4 prongs for each gauge that attach through the board. There was no access to remove them from the front. I peeled back and tried to pry them out to no avail. Eventually I found that I was able to push out the prongs, one by one, from behind.

Using a small bit to pop them out, I went very slowly as not to put too much torque on the board itself. Hard to describe, but the photo should clear it up:

I then gently disconnected the "mileage" and "hours" wires. After removing all that I was able to free the main board:

Upon inspection I do see that some of the original solders are showing small cracks. I assume this is what is responsible for my issue. I'll post again when I complete the repair with some more photos.

A few more questions:

1) Is there a place I can find cheap LED replacement bulbs?

2) Is there anything else I should look for or inspect before putting this back together?

3) Cadillackid ... how did you verify that the "needles" were in the correct spot again?

Hope this helps someone in the future.

Timelord · 10-13-2016, 09:37 PM

https://www.superbrightleds.com/cat/...cluster-gauge/

Geo Jeff · 10-13-2016, 10:15 PM

This should be a permanent post. super good info

boojiewoojie · 10-13-2016, 10:41 PM

Yeah, you've went to a lot of trouble that you didn't need to do. I've repaired a good number of these and it's very simple: just renew the solder joints of the wiring clusters on the back of the board. 10 minute job. And if I remember correctly I THINK the LED lights are T5. Just buy the cheap ones off eBay.

cadillackid · 10-14-2016, 07:40 AM

Ok that panel is a little different than the one in DEV... the one in DEV is a 1991... so looks like they made some changes...I didnt have the 4 prongs on each gauge... they were soldered to the board.... unless that is the "repair" previously made.. NOTED is the panel in DEV was not the original, it had a repair tag on it.. so perhaps it once had the glad to know I odnt need to pull the needles... because it was a PITA..

to get them back n, I powered the board up so everything Zeroed out.. fuel i knew was on Full and voltage i used a digital meter and matched it... air pressure i never disassembled as it is a mechanical gauge..

I wasnt sure the needles would stay on so I used a dab of superglue but maybe didnt need to...

mine came off very easily.. like I say it had a repair tag in it and appeared to have been soldered together.. i assumed they were all that way..

-Christopher

warewolff · 10-14-2016, 01:33 PM

Am I destroying this board? What technique am I missing?

warewolff · 10-14-2016, 05:00 PM

Quote:

Originally Posted by cadillackid

Ok that panel is a little different than the one in DEV... the one in DEV is a 1991... so looks like they made some changes...I didnt have the 4 prongs on each gauge... they were soldered to the board.... unless that is the "repair" previously made.. NOTED is the panel in DEV was not the original, it had a repair tag on it.. so perhaps it once had the glad to know I odnt need to pull the needles... because it was a PITA..

to get them back n, I powered the board up so everything Zeroed out.. fuel i knew was on Full and voltage i used a digital meter and matched it... air pressure i never disassembled as it is a mechanical gauge..

I wasnt sure the needles would stay on so I used a dab of superglue but maybe didnt need to...

mine came off very easily.. like I say it had a repair tag in it and appeared to have been soldered together.. i assumed they were all that way..

-Christopher

I just saw this! Thanks, Christopher. Didn't even think to power the board up first and re-align everything. Good tips on the fuel/charge gauges. That might be a little bit trickier. You took the measurements from the alternator with the volt meter?

In my last post I mentioned I might've been fouling things up -- I realized that both my solder and my iron are too large to tinker with the small circuitry. I was really making a mess of things. Recommendations on an appropriate iron/solder gauge or a kit that I can buy to finish this up correctly?

Lastly, has anyone swapped the mechanical gauges to electronic with success?

Thanks again Chris. You have saved me a lot of time.

cadillackid · 10-16-2016, 07:09 PM

sorry i was on the road the last 2 days.. just getting to this.. drove the new bus from tampa to columbus ohio (its intermittent gauges and all)..

If im at my house I just have a cheapie radio shack soldering iron that i bought a finer tip for.. i realize RS is gone now.. so perhaps a hobby store is where i would try.. not a hobby lobby type but like an indeopendent shop where they deal with a lot of RC panes and cars.. they often have fine-tip soldering irons for working on that small stuff.. and usually reasonably priced..

ive got my Bus in columbus now so i can take that panel out and tear it apart to see hoe much different it was than DEV... I hope i didnt foul you up to much about disassembling the gauges themselves.. my guess is whoever originally rebuilt the one in DEV soldered the gauges right into the board.. or maybe it was that way... 1990 was the first year of that panel.. DEV is a 91..

I know on the T-444E based panel that some of the gauges get their info from the PCM.. at least thats how I read it in some of the service info..

I dont think IHC ever made that dashboard style with an electronic air gauge.. that was the only on DEV which was truly mechanical.... DEV is a mechanical engine.. but each gauge has a separate sending unit.. individual gauges flaked out randomly on that bus.. esp the speedometer.. till i resoldered it.

on my T-444E bus, it appears the fuel / amps / transmission temp are all electronic gauges but use separate sending units..

speed / volts / water temp / oil press / RPM are all data fed from the engine computer.. if those gauges all randomly freeze in their positions.. ie driving along and stop but your speedo and tach still read like you are rolling, thats just 1 wire thats typically fouled up... which is what my case is on the new bus.. they all work perfectly except they randomly freeze till i reach behind and gently press that connector..

even when my other gauges are frozen my fuel gauge still works... my amp gauge is flaky on its own.. I can reach behind and press on the second connector on that oiuter row and that gauge will function... my trans temp never works because the sensor on the trans is gone...

I'll try and take good pics when I take it apart.. ,maybe we can all share notes and come up woit ha nice sticky thread on how to fix these things.. because i know theres a lot of members with the same dash.. and my guess is a lot of them dont work right..
-Christopher

boojiewoojie · 10-16-2016, 08:04 PM

The joints you've soldered look ok. Really, you don't even need to use new solder. Just touch your iron to each joint to melt the current solder and then let it cool back down. All you're redoing is the one big connector. Some buses with more gauges have two connectors.

What's happening is the the weight of the connector vibrating eventually develops hairline cracks. Most of the time you can't visually see that the connection is bad.

And if you need a new soldering iron just order one from Parts Express in Dayton OH. Good prices and fast shipping.

cadillackid · 10-16-2016, 09:05 PM

I full relamped mine with new lamp socket seats and bulbs.. those socket seats are known to go brittle on international.. i had a couple bad bulbs so figured id relamp the whole thing so i wouldnt have to take it out again...

but yeah the last post is right.. the vibrations and weight crack the solder joints.. and if that connector has ever been unplugged and replugged it makes things worse..

I didnt use any new solder on my DEV... i tinned the iron then just barely touched each joint.. till it flowed then let it cool and looked at them all with a magnifier..

I did have to fix a separate issue on one of the resistors on that board.. it eas making the fuel gauge read E when i had 1/2 tank... resoldered that resistor and its been fine..

-Christopher

cadillackid · 10-19-2016, 08:06 AM

Ok so I got int othe dash cluster on my new Bus, and it came apart like what was described here (and in the service book).. the gauges just unplugged fro mthe main board.. no removing the faces like i had to on DEV..

I can assume oin DEV a previous repair was botched resulting in soldering the gauges to the board.. or perhaps since that was the first year (1990 chassis) of that cluster it may have been done that way before they made the plug-ins..

my new cluster has some real issues.. I found a small crack in one of the boards itself... it appeared someone may have tried to take the thing out of the bus at one time or maybe they flexed it to try and get it to work... not sure...

I soldered a couple jumpers across the broken board traces.. and then found some really bad solder joints on the connectors.. like their flow solder machine at manufacture was deficient... fixed those up.. and relamped it .. I had 3 burned out bulbs.. (these clusters use a '37' bulb).. so I changed all of the bulbs..

today will be the real test when I put it back in the bus and try it.. but it was in bad enough shape i may have to send it off for repair / replacement if it doesnt work..

-Christopher

warewolff · 10-21-2016, 12:45 PM

Anyone know what size LEDs I should buy? They come in 3, 4, and 5mm.

cadillackid · 10-22-2016, 06:35 AM

these were the ones i was looking at..

T5 37 73 74 T5 LED Bulbs For Instrument Panel, Gauge Cluster Lights

our bulbs are a '37' size in the cluster like shown in the pics... that fits All of the bulbs in the cluster... background lamps as well as the idiot lights as well.. my only concern with LED's is will the light be spread properly...

the gauges 'sort of' have optics for the backlights but looks like a decent light spread is needed by the bulb rather than a spot like some LED's produce..

I havent bought any yet.. I wanted to repair my panel first to make sure i could resurrect the poor thing from its abuse before I bought any LED's for it..

if I can create a solution for the trans temp, air pressure, and amps im going to go Glass in that bus with a fully computerized panel...

-Christopher

warewolff · 10-22-2016, 09:06 PM

Quote:

Originally Posted by cadillackid

these were the ones i was looking at..

T5 37 73 74 T5 LED Bulbs For Instrument Panel, Gauge Cluster Lights

our bulbs are a '37' size in the cluster like shown in the pics... that fits All of the bulbs in the cluster... background lamps as well as the idiot lights as well.. my only concern with LED's is will the light be spread properly...

the gauges 'sort of' have optics for the backlights but looks like a decent light spread is needed by the bulb rather than a spot like some LED's produce..

I havent bought any yet.. I wanted to repair my panel first to make sure i could resurrect the poor thing from its abuse before I bought any LED's for it..

if I can create a solution for the trans temp, air pressure, and amps im going to go Glass in that bus with a fully computerized panel...

-Christopher

Fully computerized sounds enticing. I was going to go that route but didn't find any plug and play options even for the speedometer and tachometer. Do you know where you're getting the replacements?

cadillackid · 10-23-2016, 07:51 AM

the 5 main gauges on the 'E' busses (DT-466E, T-444E,DT-530E) are data-link from the ECM (speed, RPM. oil P, temp, Volts)..

the gauges below do not go through the computer
trans temp - sensor to gauge (thermistor)
Air pressure - mechanical gauge (air line direct)
Amp meter - shunt to gauge
Fuel gauge - sensor to gauge

Silverleaf electronics makes a full glass dash solutiuon with external transducers and propreitaery software.. it is actually OEM in some high end coaches... and it comes with a high end price ($6k I think)..

they also make a device (vmspc) that will read the J1708 stream and you can make your own gauges and runs on a windows PC.. it is $400 I think.. in addition to the 5 main gauges it would allow me to read some of the problem children of the HEUI system like the ICP command and the HPOP..

what remains to be seen is if I can get hold of a separate device and feed into their box..

a windows solutiuon is best for me because i could window the screen with NAVI / traffic / Music , etc.. my plan is to use a Surface pro 4 with a ssecond screen attached.. allowing me the fkexibility of other apps ..
the silverleaf pricey solution does include the capability for cameras and what not just not native windows apps...

at the very least I could custom build a panel to fit in the factory spot , using the J1708 data for my main gauges and any other data-based info i want, and then keep my original gauges for the 3 that arent part of the data stream...
-Christopher

Grease&gravel · 06-09-2018, 08:16 AM

I have the cluster apart. Which resistor is for the fuel guage? Also bulbs are T5 but what size are the sockets? Can't find them on superbrightleds website.

o1marc · 06-09-2018, 11:37 AM

Quote:

Originally Posted by Grease&gravel

I have the cluster apart. Which resistor is for the fuel guage? Also bulbs are T5 but what size are the sockets? Can't find them on superbrightleds website.

T5 LED bulb uses a T5 female socket, same as the standard T5 bulb. You can find them here:
https://www.ledlight.com/t5-wedge-so...RoCDLIQAvD_BwE

boojiewoojie · 06-09-2018, 12:57 PM

Hmm...,
I might see a tax writeoff on the close horizon. So basically the VMSpc interfaces through the ECM to a windows tablet and not only supplies a readout for the gauges (except those noted) but also engine diagnostics and a "tank minder" for calculated miles to empty?

The main reason I may seriously think about this is because of more stringent laws that went into effect this year in Tennessee. Basically, if you use any electronic device while children are on board you face jail time, a fine and permanently not being able to drive a school bus any more. Even if you pick your phone up to see the time (with nobody on the bus) and somebody calls the transportation department complaining you have to write a letter stating what you were doing.

However, the troopers are interpreting the law to allow things like back-up cameras. This would be nice to have the (accurate) time permanently displayed, diagnostics in real time (why did the engine just hesitate?!!,etc.), and not having to remember offhand what my mileage or day it was when I refueled.

Interesting.

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