Four problems related to wiring have been reported for the 1998 GMC Suburban. The most recently reported issues are listed below.
Fire then smoke coming from wire harness.
Wiring to the electric fuel pump can over heat (and possibly cause a fire) when the fuel pump fails. This would occur when the fuel pump is in a failed (locked) condition while power is applied to the pump. The electrical current draw is higher than the rating of the wiring.
Couldn't start vehicle. Attempted to replace oem delco battery with new battery and found acid had leaked from positive side terminal, totally corroding battery bolt, terminal and cables. Acid had leaked onto high pressure a/c line, electrical wiring and brake lines, corroding them. Significant corrosion on body metal. Repair estimates run in excess of $500. Negotiating with GMC for repairs under a products liability claim.
During summer of 1999, I noticed battery acid residue below battery on lines and wires. Cleaned off with oil. Brakes were mushy. In October, 2000 brakes slowed vehicle but required additional pressure to stop. Noticed additional battery acid build up on lines and wiring. Brakes failed Nov. 22, 2000. Added brake fluid. Vehicle would not start on Nov. 28, 2000. Positive battery post separated from battery. Spent two hours removing broken-off battery from battery bolt,cables and installing battery. Poured baking soda water on affected area of lines and wires.