Common electrical problems with the G body

[jmac636]

I've had two problems with my 1986 Cutlass 442.

No high speed blower:

Fix:The red wire going to the High speed relay had a bad connection. Follow the red wire into a push connector along the passenger side valve cover. I removed the wire connectors and soldered and heatshrinked the connection to fix. Look for this before replacing any parts. With the ignition on and the blower on check voltage at the highspeed relay big red wire with the relay plugged in.


My battery dummy light stayed Illuminated while the car is running:

Fix:I replaced a diode trio inside the alternator to fix the problem. I also had a slight drain in amperage from this.

I used a digital VOM (volts ohms meter) to find these problems. A meter is a must have when troubleshooting these old electrical bugs.

[SalonCutlass85]

ha good info

[88hurstolds]

Had both problems but could never figure out the heater blower one... I finally ripped out the A/C system and installed a heater box
Good to know that was the problem though.

[ralph442]

i have a few different years of gm factory electrical troubleshooting manuals, if anyone gets stuck i might be able to help

[richard.donavan]

well i got the balls up to take out my dash today, future refrence dont wait until 730 at night. today my gauges became an eq for my stereo. my gf was driving (seems like these problems never occur when i am driving) and she said the radio started to fade in and out, so she smacked the radio and the gauges started "jumping to the music". then she turned the radio off and they stopped working all together.
there are so many half assed wired connections with three different kinds of tape.
from previous events and the looks of the wiring, there has to be a crossed or exposed wire that is screwing with the whole dash system.
if anyone has a diagram that may be a little better than what i have, it would be appreciated. for now all i can do is rewire what has been poorly done before.

oh and by the way. when i pulled out the instrument cluster and housing, it has "85 Cutlass Supreme" written on it, i have the 83 calais, is this the same cluster?

[88hurstolds]

Wow, sounds like a mess
If I had a scanner I would send you a wire diagram, your best bet would be to find a Chassis Service Manual or to follow each wire to find any splices and bare wires.

The cluster is just fine, they are all virtually identical so it doesn't matter if it's from another car.
You may however want to change all the bulbs and make sure the jumper on the back of the tach is secure or even replace the jumper by soldering a piece of wire to avoid the typical erratically high reading tach that always happens.
They jumper is used to change the settings between 6 cylinders and 8 cylinders. Sometimes these can even become missing...

[74hurstolds]

I've had two problems with my 1986 Cutlass 442.

No high speed blower:

Fix:The red wire going to the High speed relay had a bad connection. Follow the red wire into a push connector along the passenger side valve cover. I removed the wire connectors and soldered and heatshrinked the connection to fix. Look for this before replacing any parts. With the ignition on and the blower on check voltage at the highspeed relay big red wire with the relay plugged in.


My battery dummy light stayed Illuminated while the car is running:

Fix:I replaced a diode trio inside the alternator to fix the problem. I also had a slight drain in amperage from this.

I used a digital VOM (volts ohms meter) to find these problems. A meter is a must have when troubleshooting these old electrical bugs.

My 87 has both of these problems currently. I tried everything for the amperage leakage. I fixed it by jumping a wire from the battery to the alternator. I'll see if this fixes it.

Going to check out the red wire now. Low and medium don't work either.

I also have the jumper issue where the tach reads high. I'll try adding a wire to it instead.