91efbluehatch

did the obd1 conversion. used a ZERG industries ecu jumper.

everything was fine all today.
i had my exhaust installed and they also had to do some cutting and welding on it while it was on the car.

drove to my college, turned on my lights and everything went super dim. i couldnt see ANYTHING.

i turned on a side road and this is what happened.

pics are from this morning





i had it grounded to the bolt on the seat rail

crx_si-r

wow. What is the ground for?

91efbluehatch

supposed to ground out the ecu/
would the welding on my car have cause more power to go to this ground and heat it up?

gringo7718

As resistance increases, the temperature will go up. This is because the same amount of electrons have to pass through a smaller surface area, and there is increased "friction".

In this case that ground cable looks pitiful and it was grounded to a seat bolt which is a horrible ground spot. (painted surfaces and the seat bracket is held on with a few spot welds). Also the longer the cable, the more resistance, so make the ground cable as short as reasonably possible.

Try something like this (scratch off the paint) and attach to a major structural panel of the vehicle.

91efbluehatch

thanks. im gonna go do that and just use a self tappin screw or something.
**** was scarin me last night. and the thought of a fire scared me even more

thanks for the helpful input

4drEF

That panel probably works fine, but as I recall, the stock ground location is at the thermostat grounding point.
Thermostat ground is on the engine block which is a solid ground. On the body panel you deal with spot welds and seam filler which aren't very solid by comparison.
You may want to run the ground to both places - run wire to thermostat ground and tap into the wire to make a panel ground as well.

Odd that the jumper harness just doesn't use the stock wiring to make this connection.
it's already there for the OBD0 ECU to use so why did they give you a spare wire to make the connection yourself???

91efbluehatch

i did have two grounds to the thermostat, and it kept shorting out the ecu fuse.
i had the vtec grounded there and something else

4drEF

VERY weird that a ground would blow a fuse.
That could be because of your poor grounding to under the seat, but maybe not.

Is your block grounded well?
There is a strap that goes from the transmission to the chassis that provides the ground for the thermostat housing.

Is your battery in the stock location?

gringo7718

Now I see you most likely have a wiring issue. Between the ecu and the ground causing you to blow fuses i would be checking over every wire, and the conversion harness. I would also find out why the grounds are causing fuses to blow, and try to fix this stuff.

91efbluehatch

battery is in stock location for now. will be located to the back.

i have the trans ground to chassis. valve cover to chassis. and i also have a ground on the chassis to the battery.

91efbluehatch

**ok just went outside to check i have the ecu grounded to the thermostat already and whenever i added the vtec ground to it, it would blow.

91efbluehatch

replaced the under hood fuse box.
here is a vid of how the car is acting.
still get the ELD code. could it be my alternator?

91efbluehatch

i de pinned the ecu jumper and put in a new plug and a new ground wire as well.
i ran the ground wire straight to the firewall where a bolt went and i secured it there.

started up just fine, but it does that whenever you turn on the headlights, blinkers, high beams etc.

where is the headlight relay located?

4drEF

I deleted that post...
sorry.
I didn't catch that you had the ELD code.

Found this and it seems related to what you have going on
https://honda-tech.com/forums/honda-crx-ef-civic-1988-1991-3/91-civic-eld-code-20-burnt-up-my-alternator-2941237/

91efbluehatch

its all good. still helpful info though.

saying as that i juts replaced the fusebox and the code still came, i think the alternator is fried.

it got it used from a friend to get the car started and running.

91efbluehatch

fixed the problem. ran a couple more grounds in the engine bay.
man i cannot stress enough how much that trans to chassis ground is

91efbluehatch

BUMP
ran into another problem.
replaced the grounds again. lights and everything work.
now when i first start it up, it goes to 3k and bounces. like in limp mode. wtf would cause that?

4drEF

Rest ECU and see what codes pop.
2k bounce is when you start it up? Or when you rev it?

91efbluehatch

ive reset ecu, check ALL my wiring. and i am getting no codes.
whenever i did start it up the other night it went straight up to 3k and bounced. no throttle what so ever.