mclarenno9

Sorry for the long intro:

Day before the autox, I drive my car around to perform some "system checks," if you will. I then shut the car off and leave it in the driveway. Later that night I go to pull it into the garage and the car cranks and it will not start.

Turns out I have no spark! So, I eventually find out that if I bridge pins 9 and 16 on the KLR plug (bypassing the KLR), my car will start. This means the ignition signal from the DME to the coil was not getting through the KLR for whatever reason.

Below are some pictures of the bad KLR. The only problem I noticed was the green resistor (R301) had pulled out of the board. There is a burn mark under it on the board. It must have gotten so hot that it either melted the solder or stressed the connection to the point of breaking. Either way, I'd like to try and fix it if possible. I have three questions...

1. Is it fixable or should I just buy a spare?

2. What may have caused this?

3. Does anyone have an internal wiring diagram of the KLR from the shop manual?

Thanks!

blown 944

there is a gentelman over on pelicanparts.com that has repaired DME's. It should be no problem for the KLR

minho78

You can measure the resistance across the resistor and get a new one and solder it.

YZ250

Replacing the resistor might fix it for a while, but something pushed too much current through it to overheat it in the first place. If you replace it, you will need to read the value off the component or look it up in the schematic. The overheating it sustained likely changed the resistance value, so a measurement could get you the wrong value.

I would think you have two options. You could replace the resistor and see how long the repair lasts. Chances are good that it or something else will blow because the fundamental problem has not been addressed. The other is to get a working KLR and be done with it, although this assumes that the source of the over-current is within the KLR itself.

APKhaos

That resistor is in the two watt to five watt range, so don't replace it with the 1/2 watt resistor from the local store. You need to find one that has the same power rating.

That resistor has been very hot. Its ohm value may have changed a bit, especailly if its a carbon on ceramic construction. Hard to tell from the pics, but if its wire wound [and not open circuit] it should be OK. Best bet is to measure the resistance on a known good unit.

The DME and KLR are treated a black boxes in factory shop manuals. No internal schematics. Guys that refurb these boxes probably have the Bosch documentation, including schematics.

Brian A.

I have a working KLR out of a 88 Turbo S. If you want it's yours for $100 shipped.

Thanks,
Brian

APKhaos

Can't beat that solution to your problem. I love this place.

mclarenno9

I went ahead and bought the KLR that Brian had. Just received it today. Plugged it in and she fired right up!

Thanks Brian!

Brian A.

Happy endings are great!