ok..about ready to rip my hair out.. I ended up having to replace the radiator sooner than expected. after installing the new radiator, fans, trans lines, hoses etc. I ran the car, bled out the air with the cap and bleeder as instructed. when the cooling fans engaged only the condensor fan came on. By process of elimination the 20Amp fuse blew. replaced and works fine. driving later that evening the car surges and chokes down. turns out my ECU fuse blew, replaced it, then the radio fuse blew, I have had no other fuses blow but is there something I should be searching for?

 

Hard to make much sense of this string of events. Only related parts are ECU and radio which share common fuse. Why are they blowing? Check alternator voltage output. Perhaps somethings going on w/ alternator.

Occasionally random events occur in sequences that imply a causual relationship, but actually mean nothing. Just a bad roll ofthe dice. Fix the problem and hope it doesn't return.

good luck

 

thats what I was thinking, its all dealt with the underhood fuses which I have never replaced since Ive had the car, maybe it was thier time to just pop?

 

OK something else is going on, I have blown 2 more ECU fuses in as many days. the car will be running at speed, then all of a sudden I'll get a jerk out of the car, the engine will slowly lose RPM's for about 3 seconds, then dies completely. the only correlation I can give is that these past 2 times the A/C has been running. other than that there have been no symptoms before it goes. I have checked all the underhood connections, they all seem to be secure/clean, and Im not finding any exposed wire anywhere.oh and I dont know if this helps but when the engine dies the D4 light starts rapidly blinking. should I try to pull codes?HELP?!

 

Take a look around the area the radiator was installed and see if there are any wires that maybe grounding out in the engine compartment.

 

Is the ECU behaving normally when the problem is not presented? Does Check Engine Light come on and then go off when keyswitch is turned to On? The 90-93 ECU's had some problems, but I don't remember your symptoms as part of this problem. It was usually AT performance issues.

I would check for codes by looking at the ECU behind the passenger foot carpet. Turn keyswitch to ON and watch the red LED to see if it flashes any codes. There are a couple of codes that don't set CEL.

The keyswitch assy could be source of the problem w/ an internal short. This seems a long shot as ECU is not fed by keyswitch.

Tough problem which will take persistence to resolve.

good luck

 

yeah other than right before the car blows the ECU fuse is runs and drives fine no other issues. the check engine light does come on and go off after a couple seconds when I start the car like normal.there are no wires around the radiator other than the fan motor wires and they are fine. I'll try the ECU and see if I get any codes. any other suggestions at where to possibly start?

 

Im stumpped, keep us updated. Im curios to know what it is. Is it still over heating? Maybe swap out the thermostat. I doubt thats the problem but it should be swapped out anyway.

 

no it never overheated, the biggest problem I had was the fan motor I had in there was too large, it kept splitting the hoses causing tranny fluid to spray everywhere. subsequently the radiator started leaking after that from a couple places in the core, then the fan motor gave out.

spring forward, got the new radiator, and smaller fan motor. got everything installed and tested it, the radiator fan still was not working, turned out it blew the fuse. replaced the fuse and all was working. later that evening the first ECU fuse blew while driving. replaced it and worked fine until last night, blew another on the way home from work, then blew another this morning, as I said the only correlation that I can think of at this point is the A/C was running the last 2 times the ECU fuse blew.

 

When you say the ECU fuse is blowing, what fuse? The ECU fuse is No. 24, a 7.5A fuse that powers ECU, ATCU, Stereo, Clock, and Automatic shoulder belt (1990 model diagram). Is this the fuse that is blowing. Fuse 24 is in lowest row, extremeLH position of underhood fuse box if you're standing on pax side peering towards underhood area.

Do you have a manual to insure you know the circuits for which you are replacing the fuse? You earlier stated ECU fuse and radio fuse are different, but they should be same circuit.

A misunderstanding of which circuitsare being affected will make diagnosis impossible.

good luck