Pulling Relays on 1990 760 T Wagon - Won't come out!

warmblood58 · Post by **warmblood58** » 18 Nov 2016, 19:29

I believe I have a fried FI Relay and found relay location on this '90 car but could not remove! Do they get that stuck or is there some trick to relay removal on these cars? My 850 relays pull right out. What gives? Just super stuck from never being removed over the years? Thanks!

warmblood58 · Post by **warmblood58** » 18 Nov 2016, 19:49

Just found a reference that suggests that the 90's have little retention clips and that the relay tray will pull out somewhat - will give this a shot

joedrt77 · Post by **joedrt77** » 19 Nov 2016, 08:04

The one on my 1990 740 was in there real good, took me a couple of tries wiggling and pulling to get it out, was stubborn. Do you suspect a bad relay?, just went thru a whole ordeal with mine, check my thread if you like.

warmblood58 · Post by **warmblood58** » 19 Nov 2016, 08:34

Thanks, pulled code 113 from OBD1 box, fuel injection which makes me believe the relay has fried. I will search for your link, thanks!

joedrt77 · Post by **joedrt77** » 19 Nov 2016, 09:27

You can make a jumper wire for testing, make sure you don't use small gauge wire tho, it will smoke and get hot, made that error on mine.

Post by **jimmy57** » 19 Nov 2016, 09:31

The sideways mounting of the 88-90 760 and the 91 940SE relays on that RH center board does cause removal issues. They did use a different relay structure where there are locating tabs to assure relays would not bee held only by the terminals. You have to counterhold the board and then wiggle and pull the relays.
To assure that the relay is the problem use a voltmeter between batt pos and a green wire at any of the injectors (slide a paper clip past the rubber seal in backside of the two wire injector connector until you feel the wire touch the terminal for a way to measure this) with engine running. A relay issue will show as volt reading of over 0.5 volt. Thumping that relay will make the reading change if solder problems or worn contacts are a problem with that injector. Do this check after car has been operated for a time to have even higher confidence of it being relay or NOT being the relay.

warmblood58 · Post by **warmblood58** » 19 Nov 2016, 14:42

Thanks Jimmy, what is the technique to slide the relay tray out on the '90 cars? is there a release mechanism to do this? Thanks!

lummert · Post by **lummert** » 19 Nov 2016, 18:18

On my 1988 760 Turbo it takes quite a bit of wiggling to get the fuel relay to come loose. This car has a radio noise suppression relay in the engine compartment. By now the wires are probably coming out of the connector.

joedrt77 · Post by **joedrt77** » 21 Nov 2016, 05:58

lummert wrote:On my 1988 760 Turbo it takes quite a bit of wiggling to get the fuel relay to come loose. This car has a radio noise suppression relay in the engine compartment. By now the wires are probably coming out of the connector.

Absolutely, my connectors were shot, on my 90' 740.

joedrt77 · Post by **joedrt77** » 21 Nov 2016, 06:03

Could try checking voltage at the fuel injector connector with multimeter, ignition on engine off, black lead to ground, red lead to connector, should be about 12 volts, I checked mine with connector off.