Jaycar Boost Controller Frying Resistor

[benro2]

Hey guys,

I've got a really annoying problem with my Jaycar boost controller (IEBC). It keeps on frying the 10 Ohm resistor near the large transistor with heatsink on the 12V power supply circuit (ie: where power goes in). The resistor glows red hot for a few seconds and then burns out, at which point the kit stops working. Sometimes when set on high boost the Hand Controller just shows a blank screen (with backlight), yet on the low boost setting it appears to be working without any problems.

However, I did have these kits working for a couple of weeks when I first installed them. Then one day it poured rain and I noticed the glowing hot resistor. I replaced the resistor a while later and started the car, and had the Hand Controller connected, and in high boost mode. The resistor started burning with a few seconds. It wasn't raining either.

A bit of a back story: I built the Jaycar Hand Controller, IEBC and DFA (Digital Fuel Adjuster) some years back and I *thought* I had made some mistakes in both the IEBC and DFA as they would continuously burn out resistors (probably the same one as what's burning out now). At that stage I had a different (stock) ECU which has since been replaced with another stock ECU. The DFA and IEBC have also been replaced with pre-built and tested units, yet now the IEBC still burns the same (?) resistor as before. So that's good in that I likely built the kits correctly, but bad in that I have no idea what could be causing this problem.

I'm certain the signal wires are going to the correct pins in the ECU as I'm getting usable readings on both kits (I also did on the original kits/ECU too). I'm hooked into the same pins as the original kits (including power supply pins). I'm using Injector 1 as the signal for the IEBC.

So I'm thinking that it's the 12V power supply that is somehow providing too much voltage. I'm no good at diagnosing these things as I have very limited knowledge of electronics so I can only guess. Am I missing something here? How would I test for this? How is it possible for the ECU to be passing through such a high voltage that it fries this resistor, yet the ECU itself is fine?

Any help is much appreciated! It's probably been about 5 years since I first built these kits and I would REALLY like to get them working!

[markdem]

gotta love jaycar kits. could you please scan all the insructions and post them? and a clear top-view picture of your completed product? cant do much without knowing what im looking at

you say it works fine on low boost which makes me think you have assembled the kit correctly. i have the small turn-knob style boost controller and the instructions say the kit was designed for a WRX, so there could be problems when trying to adapt it to other systems other than what it was designed. you dont have the same kit but the same rules apply\

very interested in solving this problem. keep us updated and good luck

[benro2]

Thanks for the help! I'm not at home right now so can't scan anything, but will try and get to it tonight (I'll be very busy all night).

However, I didn't actually build these kits (this time around). They were purchased pre-built and tested. They were working for a couple of weeks, seemingly without any problems. It's just when we had a torrential downpour that they started playing up. Possibly that's a total coincidence? I've had other electrical problems with the ECU that I thought were caused by rain, but the other night something happened that may have disproved that. Now I'm not sure if it's a problem or some automatic cycle the ECU goes through (car runs slightly rich and stutters on the highway at the SAME point in my journey, but only on a particular journey - really weird).

The kit should definitely work with my car. Plenty of people have it working on a Stagea which is essentially the same or very similar to my car, and I'm sure there are others with it working with my car too. Haven't been through the original massive thread on it in a while - I did read through it once a few years ago If you're interested, that thread is here.

[KiwiRS4T]

If you got the cable as specified in the kit it should be fine but there are other cables which fit the plugs but are not the right spec and cause melt down as you have described.

The excerpt i sent you seems to have lost the photos, possibly because the thread is now quite old but you should be able to identify the parts to be checked if you have a diagram. If you haven't, let me know and I will dig one up somehwere.

I have thrown away the original instructions but still have the book some where and remember it warning me not to switch between maps on the fly.

Hopefuly checking the values and orientation of the parts suggested will provide a solution!

[benro2]

Really sorry guys I've taken this long to get back to you. I had Christmas then holidays interstate, just no time to do anything!

gotta love jaycar kits. could you please scan all the insructions and post them? and a clear top-view picture of your completed product? cant do much without knowing what im looking at

you say it works fine on low boost which makes me think you have assembled the kit correctly. i have the small turn-knob style boost controller and the instructions say the kit was designed for a WRX, so there could be problems when trying to adapt it to other systems other than what it was designed. you dont have the same kit but the same rules apply\

very interested in solving this problem. keep us updated and good luck

I can scan all the instructions as requested, however see quote below. Maybe I'm using the wrong cable!

Also, the kits I'm using are both prebuilt and tested. I can post photos if it turns out my cable is in fact the correct one.

If you got the cable as specified in the kit it should be fine but there are other cables which fit the plugs but are not the right spec and cause melt down as you have described.

The excerpt i sent you seems to have lost the photos, possibly because the thread is now quite old but you should be able to identify the parts to be checked if you have a diagram. If you haven't, let me know and I will dig one up somehwere.

I have thrown away the original instructions but still have the book some where and remember it warning me not to switch between maps on the fly.

Hopefuly checking the values and orientation of the parts suggested will provide a solution!

I will have to look into this cable If it does turn out to just be that I will be furious!! I'll double-check the cable just to be sure I do have the correct one.

When you say they fit the plugs, do you remember if they will actually show anything on the display? Mine appeared to be working as designed for a while.

I do actually have the original instructions and Silicon Chip book/mag so will look through that about switching maps - I can't remember reading anything like that. Not saying it doesn't, probably just means it didn't read it properly

I've actually already started removing the kits from the car as I had an incident the other day where the car just cut out on its own. I think it's because a couple of the power cables touched (through some sticky tape somehow) and now the voltage readout on my ECUTalk is all over the place. Normally it's a fairly stable 13.5-13.8V but now it's anwhere between 10.5-13.5V. I measured the voltage on the battery and inside the engine bay and it's dead on 14.0V but the ECU must be seeing the voltage that the ECUTalk is showing as my idle speed has increased by about 150 rpm. When the car is off it shows a stable 10.8-11.V instead of 12.6V, so I know something is up here! I'm pretty much ready to give up but if this cable is the answer I'll reinstall them

Edited January 15, 2012 by benro2