These cars run like hell with even one GP dead. It sounds like you have at least one bad one. It's probably passing enough current to not trip the CEL but not enough to actually heat up.

1. Pull the 6 conductor plug onthe GP relay, switch on the ignition and check for 12v on all 6 pins on the relay.

2. After passing this test, switch you meter to Ohms and test between ground and each pin on the plug going to the GP's. They should all be about the same, something like .8 ohm.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250