91 Olds 98 Fuse #6 Dash, Service Engine S

I just purchased this car. 3800 Engine went to get codes and no dash lights. Fuse #6 keeps blowing when I put the key in the run position. Does anyone know a way of getting the sequence of events so I can have a starting point for looking for short? Could this be the ecm? Car doesnt start. I don't think its related as acts like cam sensor. Any help would be appreciated. This is a 1991 Olds 98 Regency Elite. Wiring diagrams on Autozone are correct for a 1992 Olds 98. I have alldata on the car but totally confused with wiring diagrams. Thank you in advance

Welcome to AF. You need to look at the diagrams and see what components are fed by#6, there is no quick answer to trace a short. I would focus on getting this running also, whatever #6 feeds may be connected to the no start, first things first.

Thank you for the response. I spent a whole day studying the diagrams only to become more confused. It feeds the dash and all the reminders. I pulled the dash apart and took gauges out and then the fuse didn't blow. I looked for a short in the panel and in the plug for the panel but can't find anything earth shattering. I just got more confused. If I knew the sequence of events then I could at least isolate the problem. There must be some relays involved I think. Does the ECM control with some timing mechanism the sequence that things happen and is there someway to stop it at a certain point? I feel like I'm babbling but I am overwhelmed at trying to trace all the wires. Roger

Are you referring to fuse #6 on the driver or passenger side?

I/P Fusebox, Drivers side, 15 Amp

After reading my responses I thought I should add some thoughts. What I mean about sequence of events and timing is when the key gets turned in the run position what actually happens first, second and so forth? I/P Fuse #6 gets Battery voltage or does a relay somewhere else get turned on to supply the voltage? Is there someway I can step through the events to see when things go bad. Is this just a monitoring circuit? For instance if a switch is bad (shorted out) in the low washer fluid circuit would this blow the fuse? (or any of the switches it is monitoring)

One more thing, I see that the #6 i/p fuse circuit connects to the ignition module. If the camshaft sensor is shorted out would this blow the i/p fuse #6? See how confused I am.

I was wrong in my previous statement I think. A switch is by definition a switch to ground. Therefore if any of the switches are bad (shorted or just in the ground position) it should not make the fuse blow it should just turn on the appropriate reminder or warning light.

Back to the get it running first!

Disconnect the wiring harness that goes to the Ignition Control Module & see if the fuse blows.

Disconnected the wiring harness from the ecm. Same thing, blew fuse. I think I will pull all the relays and if it doesnt blow I'll start putting them back one at a time. Any suggestions?

I would love to get it going first but I can't pull off any codes because of the blown fuse. I'm concerned for the wiring because if the motor is no good I will put in another, but I want the wiring fixed so I no its not the wiring thats making it a no start condition.
The one symptom the people told me about the car before I purchased it was they had trouble starting it in the rain or cold. Can this be tied into the fuse circuit that I am having problems with. It feels like a cam sensor to me. Can this be tied into the fuse thing?
Roger

You said the ignition module (ICM) is protected by fuse #6. After I suggested disconnecting the wiring harness to the ICM you said that you disconnected the wiring harness to the ECM. Did you try disconnecting the ICM? It's the module that the ignition coils are mounted to. I've never heard of a cam sensor blowing a fuse but you can also try unplugging that.

Ive unplugged ignition module along with a lot of the relays, and other items still blows fuse

I hate to complain about service manuals, but I get different wiring diagrams at alldata and az. The ones on alldata seem to be correct but wrong on certain areas like the connections of the Instrument panel to the ecm. Either that or I am a confused desperate idiot.

Once again any help would be appreciated. Any quality service manuals out there or wiring diagrams?

All I have is a Chiltons manual for the Olds 88 & that mostly covers the engine. You should see what the local library has. Can you post a link to what you found @ AZ.

I found the wiring diagram @ AZ & it's the same crappy diagram that the Chiltons manual uses. Anyway it looks like fuse #6 (6 amp not 15) is for the coolant fan relays. Are those 2 of the relays you tried removing?

BTW - that diagram shows the ICM getting power from fuse #7 not #6. It doesn't specify whether its fuse #7 in the relay center or #7 in the insrument fuse box.

The diagrams on az are wrong. The diagrams for a 92 are more correct. Fuse 6 = 15 amp ip drivers side. I just did some more tests again and found that measuring resistance to ground from the dead side of the fuse is 1.5 ohms with ignition off, 8 ohms with ign on, but I also read a .1 volt on the dead sid e of the fuse 6. So I disconnected the positive side of battery and redid ohms. Now it is 1 ohm in both positions so I'm getting some bleed of voltage that is throwing off my readings. Realistically that 1 ohm is a dead short. have about .6 ohm in my wiring in the meter. I'm going to pull off the dash gauges again and try to ohm out each wire to ground. Maybe I can get a dead short on one then at least I can identify the circuit. Tell me what you think. and thanks, its amazing when you know someone is trying to help it makes it so much easier. Its not such an alone feeling.

I'm looking at the 92 AZ diagram. It shows these items on fuse #6:
Cooling fan relays.
Fuel pump & oil pressure sender.
ICM & fuel injectors.

I'm pretty certain that the fuel pump & oil pressure sender use fuse #6 on the passenger side. I have heard of the oil senders shorting out & blowing the fuse.

I'm not sure which of the #6 fuses the ICM & injectors are on. You already disconnected the ICM so you can try disconnecting the injectors but I wouldn't expect an injector to blow a fuse until the engine is cranking.

That leaves the coolant fans as the most likely suspect but you might have already checked those. Does the owner's manual show what else is connected to that circuit?

You may have to start checking all the wires for a short to ground.

Here's a link to a shop manual on Ebay.
http://cgi.ebay.com/ebaymotors/1991-Oldsmobile-98-Regency-Elite-Service-Shop-Manual-91_W0QQcmdZViewItemQQ_trkparmsZ66Q3a2Q7c65Q3a16Q7c 39Q3a1Q7c240Q3a1318QQ_trksidZp3286Q2ec0Q2em14QQhas hZitem400009601681QQitemZ400009601681QQptZMotorsQ5 fManualsQ5fLiterature#ebayphotohosting

Thanks Mickey, I will check wires and get the manual.

Mickey thank you again, I couldn't find a short so I got frustrated and went and got a different instrument panel and that was the problem. Now I can read my codes and it looks like I was correct on the code 41. I just wanted to thank you and the forum for helping me along.
Roger

I did buy that manual and thank you,
Roger

So its no longer blowing fuses but still won't start?

The cam code can be caused by:
The cam sensor
The wiring harness that connects the cam sensor,ICM & ECM.
Sometimes the magnet that triggers the cam sensor falls out of the timing gear. You can check this by removing the cam sensor & looking for the magnet (or hole) while slowly turning over the engine with a wrench.

Yes mickey magnet is gone, going to try to file off new magnet top and JB welding it in hole. DId get the car running actually runs very nice . Will run and start easier I'm sure after magnet is in. Thanks again Roger

I have to add that the problem returned almost immediately. I ended up tracing everything and found a short in the rearview mirror circuit.