Dave Forster
Supporter
Earlier this week, the car would not start and I noticed that the fuel pumps were not running as usual when the ignition was turned on.
As it turns out, the fuel pump relay supplied with the GM Fuse Box (GM Crate Engine Computer package) was sticking, due to having being overheated and partially melted.
I'm not sure whether this is due to a fault in the relay itself, or something else, but the following may be helpful to someone else:
The original is an Omron 68W-1C7T-R-DC12 5-pin relay. These are obsolete, are no longer being produced and are difficult to find. There is no cross-reference replacement that I could find. The published datasheet shows the pin rows separated by 7.0mm. This is wrong and makes it hard to find a compatible replacement. The actual distance between rows is 7.8 mm. Some sites show an equivalent part number for replacements, but in each case, the electrical specs did not seem to be sufficient (e.g. only 10 amps rating).
At the current time, Nexus Electronics (https://nexelec.com/) has stock on the Omron relays. I ordered the minimum (3) and they arrived within 2 days. However, once their stock runs out, it is likely they will not be able to get more. Also, I wanted to find something that could be purchased from a local autoparts store, so that there are options if the relay quits at a bad time. As it turns out, ACDelco makes D-1471C, which is a $15, 4-pin relay rated for 40 amps which works as a plug-in replacement in my car (the middle pin on the Omron relay is not actually used for the fuel pump). Just make sure when plugging it in that the orientation is the same as the old relay. You can tell this by noting the cutoff middle pin on the ACDelco relay and the blank pin opening in the relay receptacle in the GM Fuse Box. You can also note the numbers beside each pin - they are the same for both relays, so if the same pin-number on the new pin goes into the same slot as the old relay, you should be good to go. Alternate part numbers for the ACDelco relay include AZ986-1A-12DC1R1 or 19106615.
As it turns out, the fuel pump relay supplied with the GM Fuse Box (GM Crate Engine Computer package) was sticking, due to having being overheated and partially melted.
I'm not sure whether this is due to a fault in the relay itself, or something else, but the following may be helpful to someone else:
The original is an Omron 68W-1C7T-R-DC12 5-pin relay. These are obsolete, are no longer being produced and are difficult to find. There is no cross-reference replacement that I could find. The published datasheet shows the pin rows separated by 7.0mm. This is wrong and makes it hard to find a compatible replacement. The actual distance between rows is 7.8 mm. Some sites show an equivalent part number for replacements, but in each case, the electrical specs did not seem to be sufficient (e.g. only 10 amps rating).
At the current time, Nexus Electronics (https://nexelec.com/) has stock on the Omron relays. I ordered the minimum (3) and they arrived within 2 days. However, once their stock runs out, it is likely they will not be able to get more. Also, I wanted to find something that could be purchased from a local autoparts store, so that there are options if the relay quits at a bad time. As it turns out, ACDelco makes D-1471C, which is a $15, 4-pin relay rated for 40 amps which works as a plug-in replacement in my car (the middle pin on the Omron relay is not actually used for the fuel pump). Just make sure when plugging it in that the orientation is the same as the old relay. You can tell this by noting the cutoff middle pin on the ACDelco relay and the blank pin opening in the relay receptacle in the GM Fuse Box. You can also note the numbers beside each pin - they are the same for both relays, so if the same pin-number on the new pin goes into the same slot as the old relay, you should be good to go. Alternate part numbers for the ACDelco relay include AZ986-1A-12DC1R1 or 19106615.
